Microadaptive Flow Control Applied to a 

Spinning Projectile 

by J. McMichael, A. Lovas, P. Plostins, J. Sahu, G. Brown, and A. Glezer 

ARL-TR-3589 September 2005 

Approved for public release; distribution is unlimited. 
NOTICES 

Disclaimers 

The findings in this report are not to be construed as an official Department of the Army position unless 

so designated by other authorized documents. 

Citation of manufacturer’s or trade names does not constitute an official endorsement or approval of the 

use thereof. 

Destroy this report when it is no longer needed. Do not return it to the originator. 
Army Research Laboratory 

Aberdeen Proving Ground, MD 21005-5066 

ARL-TR-3589 September 2005 

Microadaptive Flow Control Applied to a 

Spinning Projectile 

J. McMichael and A. Lovas 

Georgia Tech Research Institute 

P. Plostins, J. Sahu, and G. Brown 

Weapons and Materials Research Directorate, ARL 

A. Glezer 

Georgia Institute of Technology 

Approved for public release; distribution is unlimited. 
ii

REPORT DOCUMENTATION PAGE Form Approved 

OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering 

and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, 

including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson 

Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to 

comply with a collection of information if it does not display a currently valid OMB control number. 

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY)

September 2005 

2. REPORT TYPE 

Final 

3. DATES COVERED (From - To) 

October 2003–August 2005 

5a. CONTRACT NUMBER 

5b. GRANT NUMBER 

4. TITLE AND SUBTITLE 

Microadaptive Flow Control Applied to a Spinning Projectile 

5c. PROGRAM ELEMENT NUMBER 

5d. PROJECT NUMBER 

622618.AH80 

5e. TASK NUMBER 

6. AUTHOR(S) 

J. McMichael,* A. Lovas,* P. Plostins, J. Sahu, G. Brown, and A. Glezer†

5f. WORK UNIT NUMBER 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 

U.S. Army Research Laboratory 

ATTN: AMSRD-ARL-WM-BC 

Aberdeen Proving Ground, MD 21005-5066 

8. PERFORMING ORGANIZATION 

 REPORT NUMBER 

ARL-TR-3589 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) 

11. SPONSOR/MONITOR'S REPORT 

 NUMBER(S) 

12. DISTRIBUTION/AVAILABILITY STATEMENT 

Approved for public release; distribution is unlimited. 

13. SUPPLEMENTARY NOTES 

*

Georgia Tech Research Institute, Smyrna, GA 30080 

†

Georgia Institute of Technology, Atlanta, GA 30332

14. ABSTRACT 

The focus of this report is to provide a technical and programmatic summary of a Defense Advanced Research Projects Agency 

effort to explore the feasibility of producing steering forces on a spinning projectile using microadaptive flow control (MAFC). 

The report discusses the theoretical foundation for the flow control mechanism, the multidisciplinary modeling technology 

developed, the flight control technology required to enable the MAFC on spinning projectiles, the design of the flight test and

validation hardware, and the results of the open-loop flight test. The open-loop tests clearly indicate that MAFC can be used as 

a spinning projectile divert technology and extended to other subsonic munitions. Phase I of the program will conclude with a 

closed-loop test of the technology. A Phase II program has started to extend the technology to smaller diameter and higher 

velocity projectiles. The Phase II program will also investigate microgas generators as the MAFC actuator technology. 

15. SUBJECT TERMS

microadaptive flow control, guided munition, guided spin-stabilized projectile 

16. SECURITY CLASSIFICATION OF: 

19a. NAME OF RESPONSIBLE PERSON

Peter Plostins 

a. REPORT 

UNCLASSIFIED 

b. ABSTRACT 

UNCLASSIFIED

c. THIS PAGE 

UNCLASSIFIED

17. LIMITATION 

OF ABSTRACT 

UL 

18. NUMBER 

OF PAGES 

38 

19b. TELEPHONE NUMBER (Include area code) 

410-278-8878 

Standard Form 298 (Rev. 8/98) 

Prescribed by ANSI Std. Z39.18
iii

Contents 

List of Figures iv

Acknowledgments vi

1. Program Overview and Objectives 1

2. Technology Transitioning Strategy 3

2.1 MAFC Applied to a Spinning Projectile .........................................................................4 

2.2 Computational Fluid Dynamics (CFD) Modeling...........................................................8 

2.3 Projectile Design ...........................................................................................................12 

2.4 Aerodynamics................................................................................................................12 

2.5 In-bore Launch Modeling and Validation Testing........................................................14 

2.6 Telemetry System Design .............................................................................................18 

2.7 System Integration and Validation Testing...................................................................20 

3. Current and Future Program 24

4. References 26

Distribution List 28 
iv

List of Figures 

Figure 1. Schematic drawing of 80-mm wind tunnel model configuration....................................4 

Figure 2. Schematic of wind tunnel test apparatus. ........................................................................4 

Figure 3. Lift dependence on jet momentum coefficient................................................................5 

Figure 4. Transient force developed on an 80-mm body at 30 m/s. The jet is operated for 

5 ms (about one convective time scale). ....................................................................................6 

Figure 5. PIV phase-averaged measurements of the flow response to six cycles of synthetic 

jet activation...............................................................................................................................6 

Figure 6. Flow turning as a function of spanwise position with respect to the jet centerline.........7 

Figure 7. Enhanced force generated by modified aft section configuration. ..................................7 

Figure 8. Overall schematic of the electronic control system for the open-loop flight tests. .........8 

Figure 9. Schematic of synthetic jet and its location on the instantaneous velocity projectile.......9 

Figure 10. Computed magnitude contours......................................................................................9 

Figure 11. Instantaneous particle traces in the wake. ...................................................................11 

Figure 12. Lift force due to the jet vs. angle of attack..................................................................11 

Figure 13. Time-averaged aerodynamic forces. ...........................................................................11 

Figure 14. Aerodynamics experimental facility............................................................................13 

Figure 15. The 40-mm projectile at Mach 0.69. ...........................................................................13 

Figure 16. Pitch vs. yaw measured in the AEF.............................................................................13 

Figure 17. Total yaw vs. range......................................................................................................14 

Figure 18. Telemetry system design. ............................................................................................14 

Figure 19. SCORPION in-bore acceleration history. ...................................................................15 

Figure 20. SCORPION in-bore velocity history...........................................................................15 

Figure 21. FEA meshes inside the SCORPION projectile with the barrel. ..................................16 

Figure 22. Mesh on the surface of the SCORPION projectile with the barrel. ............................16 

Figure 23. The predicted acceleration load at a given node on the projectile. .............................17 

Figure 24. Effective stress contours inside the projectile. ............................................................17 

Figure 25. M781BT projectile with actuator mounting................................................................18 

Figure 26. Before and after gun launch validation of actuator jet velocity. .................................18 

Figure 27. Front and back view of the DFUZE sensor board.......................................................19 
v

Figure 28. Photographs of the SCORPION telemetry projectile showing the radome and 

battery and projectile assembly. Telemetry projectile showing the radome for the 

telemetry antenna and the battery and the projectile assembly showing the Yawsonde 

slit.............................................................................................................................................19 

Figure 29. Magnetometer data showing the projectile angle relative to the earth’s magnetic 

field. .........................................................................................................................................20 

Figure 30. Open-loop test projectile layout. .................................................................................21 

Figure 31. Solid model of open-loop projectile, sabot, and cartridge case...................................21 

Figure 32. Close-up of SCORPION projectile base showing jet orifice and Coanda surface 

fences. ......................................................................................................................................22 

Figure 33. Projectile assembly and sabot pusher system..............................................................22 

Figure 34. Projectile launch at 82 m/s and sabot pusher separation. ............................................22 

Figure 35. SCORPION open-loop test setup at the ARL Transonic Experimental Facility.........23 

Figure 36. Unpotted SCORPION open-loop flight control and sensor system. ...........................23 

Figure 37. X-rays of potted sensor system before and after 8000 g-test. .....................................24 

Figure 38. Photographs showing actuator disk, flight control electronics, projectile body, 

programming interface connector, and projectile assembly showing Coanda base 

configuration............................................................................................................................24 

Figure 39. Comparison of simulated divert and open-loop test data. ...........................................25 
vi

Acknowledgments 

The SCORPION (Self Correcting Projectile for Infantry Operation) team consisted of many 

engineers, scientists, and technicians who contributed to the overall success of the program. The 

authors of this report would like to recognize the team and express their sincere appreciation for 

all their efforts. 

Georgia Tech Research Institute: Mike Heiges and Kevin Massey 

Georgia Tech: Prof. Anthony Calise, Prof. Mark Allen, Brian English, and Chris Rinehart 

U.S. Army Research Laboratory: Dave Lyon, Dave Hepner, Tom Harkins, Tim Brosseau, 

Donald McClellan, Kenneth Paxton, and Brendan Patton 

ArrowTech: Wayne Hathaway 

Oregon State University: Prof. Mark Costello 
1

1. Program Overview and Objectives 

The Future Force Concept for the U.S. Army clearly outlines a strategy for operational scenarios 

that feature a combined-arms combat system operating in a multithreat, dynamic engagement 

environment. Precision, small- to medium-caliber munitions are integral and necessary elements 

of this strategy. To meet this vision, innovative technologies are needed to provide aerodynamic 

steering forces for small, spinning projectiles. 

With support and direction from the Defense Advanced Research Projects Agency (DARPA), 

the Georgia Institute of Technology and the U.S. Army Research Laboratory (ARL) have teamed 

on a program called SCORPION (Self Correcting Projectile for Infantry Operation) to develop 

and explore the applicability of microadaptive flow control (MAFC) technology for aerodynamic 

steering of spinning projectiles. More specifically, the program is a joint venture between 

DARPA, the Georgia Tech Research Institute’s (GTRI’s) Aerospace, Transportation, and 

Advanced Systems Laboratory, Georgia Tech’s Departments of Mechanical Engineering, 

Electronic and Computer Engineering, and Aerospace Engineering, and ARL’s Weapons and 

Materials Research Directorate. 

The SCORPION program is divided into two successive phases: an initial technology feasibility 

phase and a follow-on technology demonstration phase. The present report summarizes progress 

to-date on Phase 1, technology feasibility. The specific objective of Phase 1 is to show that 

MAFC can be integrated into a 40-mm round, an infantry grenade surrogate, to provide sufficient 

divert control authority and adequate guidance to statistically place the round within a required 

distance from the target. The second phase, now underway, has the objective of demonstrating 

that a new MAFC actuator technology based on very small-scale gas generators can be integrated 

into smaller, faster projectiles to again provide adequate control authority to enable steering and 

guidance. 

The Phase I goals are as follows: 

1. Investigate the nonlinear projectile aerodynamics associated with MAFC. 

2. Design and implement a piezoceramic actuator-driven synthetic jet system that includes onboard electronic power conditioning and device drivers. 

3. Develop an approach for generating aerodynamic control forces using MAFC, and 

demonstrate that the required divert authority can be generated on low subsonic velocity 

projectiles. 

4. Develop a flight control system for a spin-stabilized infantry grenade with MAFC 

actuators.
2

5. Design and build the required miniature high-g sensor and flight control systems. 

6. Integrate the actuator and flight control system in a 40-mm projectile test bed. 

7. Develop the multidisciplinary tools to model all aspects of the system. 

8. Validate all the subsystems with laboratory and flight testing. 

9. Perform an open-loop flight test to verify divert authority. 

10. Perform and complete a closed-loop system demonstration of the 40-mm system. 

11. In parallel with the previous goals, conduct the research necessary to develop alternative 

actuator concepts for future application to smaller, faster projectiles. 

Phase 1 began near the end of FY01 and will be completed in FY04. Goals 1–9 have been 

completed successfully. Goal 10 will be completed in September 2004. Goal 11 has also been 

completed, and the concepts and fabrication methods will be further refined and demonstrated 

during Phase 2. The present report summarizes the work up to and including the 

accomplishment of goal 9, the open-loop flight test verification of the effectiveness of MAFCgenerated steering forces. 

The SCOPRION Phase 2 technology demonstration project is a recently launched 30-month 

follow-on project designed to evaluate advanced microgenerator actuator technology and apply it 

to achieve adequate MAFC-based divert capability in a high subsonic velocity 25-mm projectile. 

This will require the development of advanced MAFC approaches and further miniaturization of 

sensor and flight control systems. This is a critical step towards transitioning MAFC technology 

into block upgrades to provide guidance for currently planned unguided munition systems such 

as the 25-mm objective crew served weapon. 

The goals of the Phase 2 technology demonstration project are as follows: 

1. Develop g-hardened gas generator actuators and fabrication technology. 

2. Design, build, integrate, and test power, processor, and driver electronics for gas generator 

actuator systems. 

3. Research the nonlinear aerodynamics associated with the application of MAFC gasgenerator actuators to high subsonic velocity spinning projectiles, beginning with 40 mm at 

lower speeds and continuing to 25-mm projectiles at high subsonic velocities. 

4. Integrate actuators and electronics into the flight control system. 

5. Miniaturize and g-harden the complete actuator, driver, and flight control system for launch 

in a surrogate 25-mm projectile. 

6. Perform an open-loop divert validation flight test of a gas generator actuator system using a 

40-mm projectile at Mach 0.25.
3

7. Perform an open-loop divert validation flight test of a gas generator actuator system using a 

25-mm projectile at Mach 0.6–0.8. 

2. Technology Transitioning Strategy 

To successfully transition DARPA’s advanced MAFC technology rapidly to the warfighter, the 

product program managers (PMs), e.g., Program Executive Officer of Ammunition, need to have 

the technology delivered to them in a state that allows a seamless transition to system 

development and demonstration (SDD). This requires that the following several critical 

technologies/demonstrations be in place at the end of the program: 

1. An integrated set of technology demonstrations of the enabling technology suite. 

2. An identified path to the realization of a tactical system, i.e., the ability to integrate other 

aspects of the system such as the warhead, munition cartridge interface, or safety 

certifications. 

3. An identified path to the required manufacturing capability. 

4. A complete modeling and simulation suite of tools to be available for SDD redesign and 

integration. 

5. Early collaboration with the PM so that the technical and financial interface will be in place 

at the proper transition point. 

The current SCORPION program has incorporated specific thrusts in order to address these 

requirements, including item 5. This philosophy has benefited the program both technically and 

programmatically by bringing focus, synergy, and overall guidance to the effort. A specific 

example is the concurrent development of high-performance computing multidisciplinary design 

tools to model the flow physics and combine the nonlinear fluid dynamics associated with the 

particular MAFC approach with the nonlinear rigid body flight dynamics. This has helped us 

understand the complex time-dependent fluid dynamics interaction with the spinning projectile 

and enabled us to increase the divert forces generated by MAFC. It has also contributed to the 

definition and design of the flight control system. 

The rest of this report will present an overview of past MAFC technologies developed to the 

present. A discussion of the test article design and subsystem validation will follow as well as 

the description of the system integration and validation tests. Finally, a short discussion of the 

planned future work and the transition of the technology to a higher velocity class of projectiles 

will be presented.
4

2.1 MAFC Applied to a Spinning Projectile 

Synthetic jets were used to develop the control forces on the spinning projectile. Configuration 

details were derived through a series of tests that used several wind tunnel test models with 

diameters of 40, 80, and 120 mm. Most of the testing involved the 80-mm model. The final 

configuration was tested in detail at the 40-mm scale. Synthetic jet actuators were used for the 

experiments. The wind tunnel model configuration is shown schematically in figure 1. 

Figure 1. Schematic drawing of 80-mm wind 

tunnel model configuration. 

The general concept is to produce normal (lift) forces by creating an asymmetric flow pattern 

with separated flow on one side and flow attached to a Coanda surface on the other. Separated 

flow is created by the rearward-facing step near the aft end of the body, where the lip of the step 

fixes separation uniformly around the circumference of the body. The wind tunnel model was 

equipped with four aft-directed synthetic jets located at the base of the backstep; they extended 

36°, azimuthally. When one of the jets was activated, it entrained external flow and pulled it 

around the curved Coanda surface, producing some streamline curvature in the external flow 

with associated lift on the body. 

The effectiveness of this configuration was evaluated experimentally using the wind tunnel 

apparatus depicted schematically in figure 2. 

Figure 2. Schematic of wind tunnel test apparatus.
5

Details of the wind tunnel test results, presented in Rinehart et al. (1), are only summarized here. 

Aerodynamic control forces (and associated moments) are generated using synthetic jet actuators 

driven by a piezolectric diaphragm operating at its fundamental cavity resonant frequency. This 

actuation frequency is ~20× higher than the shedding frequency of the body. The flow 

downstream along the centerline typically turns through nearly 90° at maximum actuator output. 

In most of the experiments with the 80-mm model, the radius of the Coanda surface is 13 mm, 

and the adjoining backward facing step is 1.5 mm high. The step height is shallow enough to 

enable local flow attachment when the control jet is activated but high enough to prevent 

attachment in the absence of the jet. The steady lift generated by continuous actuation is shown 

in figure 3 as a function of jet momentum coefficient. 

Figure 3. Lift dependence on jet momentum 

coefficient. 

The lift rises dramatically as jet strength increases up to momentum coefficient values of 

~5 × 10–5. This is associated with the initial reattachment of the separated shear layer 

downstream of the backstep. The lift increases more slowly at higher momentum coefficients as 

the flow is progressively turned to greater angles around the Coanda surface. Although the jet 

strength is relatively weak (i.e., the control input is small), with blowing ratios of only ~0.5, the 

global effect is quite large, with ratios of normal force (lift) coefficient to jet momentum 

coefficient reaching values as large as 200. This compares to values of this ration of ~80 

obtained on two-dimensional airfoils by steady blowing at much higher blowing ratios (2). 

For a spinning projectile, the control jet cannot be operated continuously. The actuator is in a 

position to favorably direct a steering force in any given direction for only a portion of a spin 

cycle, about a quarter cycle, as determined empirically. If the spin period is 16 ms, then only 

4 ms are available for the jet to operate, i.e., only four cycles of the synthetic jet diaphragm 

are available to generate the necessary steering forces. Figure 4 shows the transient force 

development on an 80-mm body with a free stream velocity of 30 m/s. The jet is operated for 

5 ms, about one convective time scale.
6

Figure 4. Transient force developed on an 80-mm body at 30 m/s. The jet is 

operated for 5 ms (about one convective time scale). 

To see the flow response to transient activation of the synthetic jet, particle image velocimetry 

(PIV) measurements were made, phase conditioned to the jet activation signal. The jet was 

operated for six cycles (6 ms) and then turned off. The flow response is shown in figure 5. 

Figure 5. PIV phase-averaged measurements of the flow response to six 

cycles of synthetic jet activation. 

Careful inspection of the figure shows the first vortex pair emerging from the orifice at the first 

quarter cycle of the jet diaphragm (t/T = 0.25). As this pair grows to full strength, the separated 

shear layer is cut off, leaving a starting vortex structure in the wake. As the third vortex pair 

emerges (t/T = 2.25), significant flow turning has already been achieved. Full turning is evident 

after six diaphragm cycles (about one convective time scale for the 80-mm wind tunnel model). 

For a 40-mm spinning body traveling at 70 m/s, the convective time scale is ~1 ms, based on 

body length (~75 mm). So the flow response should be much faster, and five cycles of jet 

operation should produce force levels approaching quasisteady values after only 2 or 3 ms. 

Here, the time scale of the actuator diaphragm is about the same as that for the global flow 

(convective time scale). 
7

Detailed wind tunnel tests were conducted to examine several aspects of the body and actuator 

configuration, including Coanda radius and the effect of the step height. An important 

question concerns the extent to which the flow behaves more or less two dimensionally 

(axisymmetrically) downstream of the actuator. Near the edges of the jet, the backstep influence 

can cause significant three-dimensional (3-D) effects. Figure 6 shows the flow turning achieved 

at the jet centerline, at midspan, and at the edge of the jet. 

Figure 6. Flow turning as a function of spanwise position with respect to the 

jet centerline. 

It is evident that there is no reattachment at the edge of the (θ = 18°), and that even at midspan 

the flow detaches after partial turning. It was determined through a series of tests that better 

attachment could be achieved by reducing the step height and providing a channeled region that, 

in effect, places strake-like fences at the edges of the channels. The lift force achieved by this 

modified configuration is shown in comparison to the original configuration in figure 7. 

Figure 7. Enhanced force generated by modified aft section configuration. 
8

The net effect is an increase in the force generated under continuous actuator operation by a 

factor of 2.5, at the higher Reynolds numbers. This is the configuration that was chosen for the 

flight demonstrations. 

Following full system design, g-hardening, and integration, flight tests were conducted to assess 

the effectiveness of our MAFC approach in generating lateral movement of the projectile in 

flight. Lateral forces were generated by operating a single synthetic jet actuator at maximum 

output for one quarter of every revolution. To consistently direct the lateral force, roll angle 

must be measured. This is because the projectile spin rate decreases along the trajectory, which 

precludes the use of a simple timing algorithm. On-board magnetometers were used to detect the 

roll angle and provide an index to the electronic driver for the actuator. 

The overall electronic system is shown schematically in figure 8. The on-board system includes 

batteries, power conditioning, a g-switch to sense launch, magnetometers to measure roll angle, a 

processor to determine when the actuator is in the proper position to produce a force in the 

desired direction (left or right), and the driver that provides the oscillatory signal to the synthetic 

jet diaphragm when the body is at the proper range of roll angles. 

Figure 8. Overall schematic of the electronic control 

system for the open-loop flight tests. 

2.2 Computational Fluid Dynamics (CFD) Modeling 

As part of the DARPA SCORPION program advanced state-of-the-art, time-accurate CFD 

techniques have been developed and applied to a new area of aerodynamic research on synthetic 

jets for control of subsonic projectiles. Cutting-edge CFD technology has been successfully 

applied to modeling microadaptive flow control. This research has provided an increased 

fundamental understanding of the complex, 3-D, time-dependent aerodynamic interactions 

associated with microjet control for yawing spin-stabilized projectiles. Detailed flow physics 

simulations have captured all the flow structures with high fidelity and successfully identified the 

locations of synthetic microjets for optimum aerodynamic interference and control authority. 
9

The control of the trajectory of a 40-mm spinning projectile is achieved by altering the pressure 

distribution on the projectile through forced asymmetric flow separation (figures 9 and 10) using 

the Coanda effect (3, 4). Time-accurate CFD modeling capabilities were developed and used to 

assist in the design of the projectile shape, the placement of the synthetic actuators, and the 

prediction of the aerodynamic force and moments for these actuator configurations. 

Additionally, the advanced CFD capabilities provided a simpler way to explore various firing 

sequences of the actuator elements. 

Pulsating 

Synthetic Jet 

Diaphragm 

Synthetic

Jet

Lift

Figure 9. Schematic of synthetic jet and its location on 

the instantaneous velocity projectile. 

Figure 10. Computed magnitude contours. 

Time-accurate unsteady CFD computations were performed to predict and characterize the 

unsteady nature of the synthetic jet interaction flow field produced on the projectile for various 

yaw and spin rates for fully viscous turbulent flow conditions. Turbulence was initially modeled 

using a traditional Reynolds-Averaged Navier-Stokes (RANS) approach. Although this 

approach provided some detailed flow physics, it was found to be less accurate for this new class 

of unsteady flows associated with synthetic jets. In order to improve the accuracy of the 

numerical simulation, the predictive capability was extended to the higher-order hybrid 

RANS/LES (large eddy simulation) approach (5). This new approach computed the large eddies 

present in the turbulent flow structure and allowed the simulation to capture, with high fidelity, 
10

additional flow structures associated with the synthetic jet interactions in a time-dependent 

fashion. Modeling of azimuthally-placed synthetic microjets required tremendous grid 

resolution, highly specialized boundary conditions for the jet activation, and the use of advanced 

hybrid LES approach permitting local resolution of the unsteady turbulent flow with high 

fidelity. The addition of yaw and spin while the projectile is subjected to the pulsating microjets 

rendered predicting the forces and moments as a major challenge. 

This capability has provided fundamental understanding of fluid dynamics mechanisms 

associated with the interaction of the unsteady synthetic jets and the projectile flow fields (6). 

Many flow-field solutions resulting from the simulation of multiple spin cycles, and hence a 

large number of synthetic jet/flow fields, were saved at regular intermittent time-intervals to 

produce movies to gain insight into the physical phenomenon resulting from the synthetic jet 

interactions. The unsteady jets were discovered to break up the shear layer coming over the step 

in front of the base of the projectile. It is this insight that was found to substantially alter the 

flow field (making it highly unsteady) both near the jet and in the wake. This, in turn, resulted in 

asymmetric pressure distributions that produced the required forces and moments even at 0° 

angle of attack. Time-accurate velocity magnitude contours (figure 2) confirm the unsteady 

wake flow fields arising from the interaction of the synthetic jet with the incoming free stream 

flow at Mach = 0.24. Figure 11 shows the particles emanating from the jet and interacting with 

the wake flow, making it highly unsteady. More importantly, the breakup of the shear layer is 

clearly evidenced by the particles clustered in regions of flow gradients or vorticity. Verification 

of this conclusion is provided by the excellent agreement between the predicted (solid line) and 

measured (solid symbols) values of the net lift force due to the jet (figure 12) for a nonspinning 

case at GTRI. The net lift force was determined from the actual time histories of the highly 

unsteady lift force. An example of the time-dependent aerodynamic forces resulting from the jet 

interaction (jet is on and off during spin cycle) for the actual spinning case at 0° angle of attack 

and computed with the new hybrid RANS/LES turbulence approach is shown in figure 13. The 

computed lift force, along with other aerodynamic forces and moments and directly resulting 

from the pulsating jet, was then used for the design of the actuator, flight control, and sensor 

system required to provide the desired course correction for the projectile. The results showed 

the potential of CFD to provide insight into the jet interaction flow fields and provided guidance 

as to the locations and sizes of the jets to generate the maximum control authority required to 

maneuver a spinning projectile to its target with precision. In addition, a multidisciplinary 

coupled CFD and rigid body dynamics technique was developed and demonstrated the effect of 

microadaptive flow control on the flight trajectories through a “virtual” fly-out of a projectile on 

the supercomputers. 

The ability to use the advanced CFD simulation of this complex flow field was critical to 

understanding the microadaptive flow control mechanism and a successful open-loop diverting 

projectile design. This research is at the forefront of technology in the projectile aerodynamics 
11

Figure 11. Instantaneous particle traces in the 

wake. 

Figure 12. Lift force due to the jet vs. angle of 

attack. 

Y

Z

Jet-on

-0.1

0

0.1

0.2

0.3

0 5 10 15

Time (ms)

Forces (Newton)

F y F z

l

Jet on Jet off -0.1

0

0.1

0.2

0.3

0 5 10 15

Time (ms)

Forces (Newton)

F y F z

l

Jet on Jet off

Figure 13. Time-averaged aerodynamic forces.
12

area and represents a major increase in capability for determining the unsteady aerodynamics of 

projectiles in a new area of flow control. This research has shown that microadaptive flow 

control with tiny synthetic jets can provide an affordable route to lethal precision-guided infantry 

weapons. 

2.3 Projectile Design 

The testbed projectile for the SCORPION program is based on the M781BT practice grenade. 

This testbed projectile was chosen because cartridge hardware, propellant, and launch tubes were 

readily available for the program. In order to determine if the projectile could be diverted, it was 

first necessary to get a complete aerodynamic characterization of the nonlinear flight dynamics 

of the base design. It was required to assess the aerodynamics over the entire trajectory as well 

as develop a ground truth system to evaluate the functionality of all of the subsystems in flight. 

To this end, a complete telemetry and sensor system was designed for the projectile. The basis 

for this telemetry and sensor system is the ARL DFUZE described in references (7–9). Since the 

grenade is tube launched at ~10 kg, a comprehensive in-bore model was developed to predict the 

in-bore launch forces (10–12). This modeling effort was combined with specific high-g 

laboratory testing of the subsystem technologies to verify launch survival. The tactical 

configuration could not be used because wind tunnel tests of the microadaptive flow control 

concept using the Coanda effect indicated that a smooth forebody was required to achieve the 

desired effect. A sabot/pusher system was developed and tested to launch the configuration 

required. A short summary and selected examples of each of these efforts will be presented in 

the next sections. 

2.4 Aerodynamics 

The 40-mm grenades are subsonic projectiles with highly nonlinear aerodynamics. The 

projectiles are spin stabilized and have classic magnus moment instabilities that result in yaw 

growth and limit cycles during the downrange trajectories. This was the first attempt to develop 

a flight control and divert system for a highly spun projectile with this class of nonlinearity. It 

was therefore important to understand all of the aerodynamic nonlinearities and flight dynamics 

along the entire trajectory. This data would allow the design of a controller that could divert the 

round without driving it unstable prior to impact. 

A series of aerodynamics tests were conducted in the Aerodynamics Experimental Facility 

(AEF) (13). The AEF is an indoor orthogonal spark shadowgraph test facility designed to obtain 

complete projectile and missile aerodynamics. It contains 37 orthogonal spark shadowgraph 

stations over 100 m of instrumented length. It can obtain both linear and nonlinear aerodynamics 

of flight vehicles from 2 to 40 mm in diameter. The facility can provide both static and dynamic 

aerodynamic stability derivatives. The SCORPION baseline projectile was tested, and a 

complete set of nonlinear aerodynamic coefficients was obtained. These coefficients included 

drag, yaw drag, lift, moment, pitch damping, roll damping, magnus moment, and cubic magnus 
13

moment (14, 15). Figure 14 is a photograph of the AEF, and figure 15 is a spark shadowgraph of 

the 40-mm projectile in flight at Mach 0.5. The data clearly showed that the projectile had the 

classic fast mode/slow mode angular behavior (see figure 16). The projectile showed a magnus 

instability in the fast mode (see figure 17). Over the length of the measurement distance in the 

AEF, 60 m, a small growth in the fast mode can be noted. This warranted further investigation 

and was addressed with a long-range free flight using the telemetry system described in the next 

section. It was necessary to do this to ascertain the exact extend of the yaw growth along the 

trajectory of interest. 

Figure 14. AEF. 

Figure 15. The 40-mm projectile at Mach 0.69. 

Figure 16. Pitch vs. yaw measured in the AEF.
14

Figure 17. Total yaw vs. range. 

2.5 In-bore Launch Modeling and Validation Testing 

In order to understand the launch behavior of the projectile, DYNA3D was used to analyze the 

projectile mechanical behavior and dynamic response. This was necessary in order to design for 

the survivability of the on-board electronics during the in-bore launch. The forward launch loads 

are ~ –10 kg; however, significant transverse loads due to balloting can also damage the 

electronic subsystems. The simulation model consisted of 17 components and five materials (see 

figure 18). The stress states and deformation in different parts are analyzed as a function of inbore time. The projectile muzzle exit velocity and the maximum acceleration in-bore were 

matched to experimental data to ensure simulation fidelity. Two composite boards inside the 

projectile are studied in detail to ensure that the deformation was small enough so that the 

electronic components were not effected during the launch. The projectile is launched from a 

rifled barrel; the full spin rate is modeled in DYNA3D. 

Head 

Batter

Battery Support 

Bore 

Body 

Back Cover 

Tungsten Ring Steel Sleeve 

Sensor board 

Processor board 

GTRItm Brd 

DSP56F803 

Analog cell 

ADXL250 

Resin

Figure 18. Telemetry system design. 
15

Critical components were also tested for high-g survivability in high-g laboratory facilities of 

ARL. A specific example of the results will be given for the piezoceramic actuators.

In order to investigate the SCORPION dynamic mechanical response and launch behavior, a 

finite-element method was used to perform a full-scale simulation. A full 3-D Lawrence 

Livermore National Laboratory code, DYNA3D (11), was adopted for the analysis. The input 

required includes geometric data, mechanical data, and projectile base pressure. Using the 

computer-aided design (CAD) software SOLID WORKS (16), the SCORPION finite-element 

analysis (FEA) model was generated. There are a total of 17 modeled parts in the model. The 

interfaces of each part are guaranteed to be geometrically accurate by using the CAD package. 

The model input mechanical data includes modulus, poison ration, and density. The mechanical 

properties for most of the parts are available from the engineering handbook (17). For the 

unavailable mechanical data required for the chips and potting compound, reasonable values are 

estimated. The projectile base pressure is obtained from the experimental data and matched to 

interior ballistic calculations. The ARL IBHVG2 interior ballistics code was used to predict the 

in-bore and projectile base pressure history (18). The in-bore acceleration history is given in 

figure 19 and the velocity in figure 20. 

Figure 19. SCORPION in-bore acceleration history. 

Figure 20. SCORPION in-bore velocity history.
16

The meshes used on the DYNA 3-D FEA model are shown in figures 21 and 22. The need for 

the complete dynamic FEA simulation is clearly seen in figure 23. The smooth acceleration load 

predicted by the IBHVG2 code is not what the projectile experiences; this is the smooth line in 

figure 23. The simulation clearly shows the high-frequency dynamic state of stress experienced 

by the projectile. This environment has g-loads that peak at least 2.5× higher than the g-load 

predicted by IBHVG2. These high-frequency loads are usually responsible for damaging the 

electronics during gun launch. The simulation indicated that the rear sensor board was subjected 

to significant stress levels; this is the high stress red area in figure 24. This information was used 

to help design the mounting and potting system for the electronics boards needed for the 

telemetry and guidance systems. 

Figure 21. FEA meshes inside the SCORPION projectile with the barrel. 

Figure 22. Mesh on the surface of the SCORPION projectile with the barrel. 
17

Figure 23. The predicted acceleration load at a given node on the projectile. 

Figure 24. Effective stress contours inside the projectile. 

All of the subsystems used in the program were shock tested and then gun launched in surrogate 

projectiles. If the components passed the shock tests in the laboratory, they were integrated into 

specially-designed projectile surrogates to verify launch survivability. This was necessary since 

the effect of spin could not be duplicated in the laboratory tests. These projectiles were 

recovered after gun launch, and the subsystems were retested for function and compared to the 

no-load performance. The example given here is for the piezoceramic actuators that are used to 

divert the projectile. The actuators were shock table tested to 9600 g. An M781BT projectile 

was modified to carry the actuators out of the gun. The modified projectile with the actuator 

mounting is shown in figure 25. Two projectiles were launched with maximum g-loads of 6800 

and 8538 g, respectively. Figure 26 is a comparison of the variation of maximum jet velocity vs. 

frequency before and after the gun launch test. Clearly, the piezoceramic actuator survived the 

gun launch intact and functioning.
18

Figure 25. M781BT projectile with actuator mounting. 

Figure 26. Before and after gun launch validation of 

actuator jet velocity. 

2.6 Telemetry System Design 

A telemetry system was designed for the SCORPION projectile and program. The purpose was 

twofold—(1) to provide a ground truth sensor system for subcomponent tests and (2) to be used 

as the sensor suite for the guidance navigation and control system. The SCORPION telemetry 

system is based on the ARL DFUZE sensor system (7, 8). The system has a three-axis 

magnetometer, four radial accelerometers, an axial accelerometer, and a two-axis accelerometer 

for transverse acceleration. The system also has a suite of four Yawsondes (9). The 

magnetometers are used to measure the projectile orientation to the earth’s magnetic field as well 

as the roll angle. The Yawsondes measure the projectile angular orientation to the sun. This set 

of angles completely identifies the angular state of the projectile. The accelerometer suite 

measures the accelerations in the x, y, and z directions. An encoder board is included to process 

the data and telemeter the data to the ground station. Figure 27 is a photograph of the front and 

back side of the DFUZE sensor suite. Figure 28 contains photographs of the SCORPION.
19

4 Radial Accels 

1-Axis Axial Accel 2-Axis Radial Accel

3-Axis Mag 

Inertial Sensor Suite 

Figure 27. Front and back view of the DFUZE sensor board. 

Figure 28. Photographs of the SCORPION telemetry projectile showing the radome 

and battery and projectile assembly. Telemetry projectile showing the 

radome for the telemetry antenna and the battery and the projectile 

assembly showing the Yawsonde slit. 

The telemetry system was used to obtain the projectile flight dynamics along the trajectory. 

Figure 29 is the magnetometer data from a SCORPION flight. The data confirmed that the 

projectile has a slowly growing fast mode magnus instability. The data was used to update the 

aerodynamics model and do trajectory modeling that showed that the divert forces derived from 

the Coanda effect would not overdrive the flight dynamics. The telemetry test was critical in 

proving that a spin-stabilized projectile with nonlinear aerodynamics could be diverted and 

controlled.
20

Figure 29. Magnetometer data showing the projectile 

angle relative to the earth’s magnetic field. 

2.7 System Integration and Validation Testing 

All the previous research, data, wind tunnel testing, computational modeling, and validation were 

used to design the integrated projectile system for an open-loop test to demonstrate that 

trajectory divert could be achieved using microadaptive flow control and the Coanda effect. The 

open-loop test required the design of a launch system, a sensor system, a processor system, an 

actuator driver board, and the actuator Coanda surface interface. The layout of the projectile is 

presented in figure 30, and a solid model of the projectile is shown in figure 31. The Coanda 

surface had to be fitted with fences to enhance the jet interaction. This was determined from 

wind tunnel tests performed at GTRI. The fences can be seen in the close-up of the projectile 

base in figure 32. The wind tunnel tests also indicated that the aerodynamic surface of the 

projectile needed to be smooth as it approached the step where the actuator orifice is located in 

order for the Coanda effect to develop the divert force. This fact required a sabot pusher system 

to be developed in order to launch a projectile that did not have an obturator band on the 

projectile body forward of the step. This pusher sabot was successfully developed and tested in 

the ARL AEF. A photograph of the sabot pusher is given in figure 33, and figure 34 provides a 

high-speed launch photograph of sabot pusher separation. 

The open-loop test flight control system was designed to initially divert at a given distance from 

the gun muzzle and then continuously divert to the left or the right. The test was conducted at 

the ARL Transonic Experimental Facility. Figure 35 is photograph of the test setup looking 

downrange towards the 200-m target. The sensor system measured its orientation to the earth’s 

magnetic field and thus determined the appropriate divert direction. The projectile flight control 

system was reprogrammable; this feature was used extensively. The electronic and sensor 

system proved to be so robust that one projectile was reprogrammed and launched 10 times. It 

was still functional at the end of the test. The flight control system is shown in figure 36. As 

with the sensor and telemetry system, the divert flight control system was assembled and 

g-tested prior to final assembly. The system was potted, g-tested, x-rayed to verify structural 
21

 Batteries 

Piezoactuator 

Driver Board 

Boost Converter 

Processor Board 

 SCORPION Layout 

 Coanda Tail 

 Connector Board 

Figure 30. Open-loop test projectile layout. 

Figure 31. Solid model of open-loop projectile, sabot, and cartridge case. 
22

Figure 32. Close-up of SCORPION projectile 

base showing jet orifice and 

Coanda surface fences. 

Assembly 

Sabot/Pusher 

Projectile 

Figure 33. Projectile assembly and sabot pusher system. 

6 ft 12 ft 

 Sabot/Pusher Separation 

Figure 34. Projectile launch at 82 m/s and sabot pusher separation. 
23

Figure 35. SCORPION open-loop test setup at the ARL 

Transonic Experimental Facility. 

Figure 36. Unpotted SCORPION openloop flight control and sensor 

system. 

integrity, and then bench tested. Photographs of the unpotted assembly and the pre- and post-gtest x-rays are shown in figure 37. The final assembly and assembly components are given in 

figure 38. 

The open-loop test successfully demonstrated the divert authority of the system. The projectiles 

were programmed to divert both left and right, and the impacts measured on the target at 200 m. 

These results can be seen in figure 39. Also plotted in the figure are simulations of the divert 

simulated data using the BOOM code (19). The code is a full 6 degree-of-freedom trajectory 

simulation including an imbedded model of the guidance navigation and control sensors. The 
24

Figure 37. X-rays of potted sensor system before and after 8000 g-test. 

Figure 38. Photographs showing actuator disk, flight control electronics, projectile body, 

programming interface connector, and projectile assembly showing Coanda base 

configuration. 

left, right, and no divert data are simulated using random initial conditions. The simulated 

impacts are plotted using the plus symbols. The vertical dispersion in the simulation is mostly 

due to muzzle velocity variation. The center of impact of the simulated vertical dispersion is 

indicated by a black cross. The actual open-loop test data are plotted as stars. The control 

authority demonstrated sufficiently eliminates all of the vertical dispersion. 

3. Current and Future Program 

The current program is concluding its last phase. A closed-loop test will be conducted to 

demonstrate that there is enough control authority to reduce the level of vertical dispersion to 

that of the horizontal dispersion. This is tantamount to negating the dispersion due to muzzle 

velocity variation. The program to date has demonstrated that MAFC can be used on subsonic 

projectiles and within elliptic flow fields to generate significant forces. The forces generated are 

capable of diverting 40-mm projectiles to levels that have tactical utility and application. 
25

Left Divert No Divert Right Divert

Figure 39. Comparison of simulated divert and open-loop test data. 

The SCORPION program has been chosen as a DARPA demonstration program to further the 

application of MAFC to higher-velocity, smaller-diameter projectiles. The program will look at 

miniaturization of the sensor systems, higher-strength miniature combustion actuators, midbody 

divert schemes, effects of subsonic compressibility, higher g-load launches, and higher projectile 

spin rates. This level of MAFC and guided projectile technology will be required for the 

medium-caliber munitions being considered for the Future Combat System. 
26

4. References 

1. Rinehart, C.; McMichael, J.; Glezer, A. Transitory Flow and Force Development on a Body 

of Revolution Using Synthetic Jet Actuation; AIAA Paper No. 2003-0618, January 2003. 

2. Englar, R. J. Circulation Control Pneumatic Aerodynamics: Blown Force and Moment 

Augmentation and Modification; Past, Present, and Future; AIAA Paper No. 2000-2541, 

June 2000. 

3. Amitay, M.; Kibens, V.; Parekh, D.; Glezer, A. The Dynamics of Flow Reattachment Over 

a Thick Airfoil Controlled by Synthetic Jet Actuators; AIAA Paper No. 99-1001, January 

1999. 

4. Rinehart, C.; McMichael, J. M.; Glezer, A. Synthetic Jet Based Lift Generation and 

Circulation Control on Axisymmetric Bodies; AIAA Paper No. 2002-3168. 

5. MetaComp Technologies. CFD++ User Manual Version 3.5.1; Argoura Hills, CA. 

6. Sahu, J. Unsteady Numerical Simulations of Subsonic Flow Over a Projectile With Jet 

Interaction; ARL-TR-2975; U.S. Army Research Laboratory: Aberdeen Proving Ground, 

MD, May 2003. 

7. Davis, B. S.; Brown, T. G.; Condon, D.; Hepner, D.; Myers, S. Development of an 

IMU/Telemetry System for Range Flight Testing of Missiles and Rockets. Proceedings of 

the 18th International Ballistics Symposium, San Antonio, TX, October 1999. 

8. Harkins, T.; Davis, B. S.; Hepner, D. Novel On-Board Sensor Systems for Making Angular 

Measurements on Spinning Projectiles. Proceedings of the SPIE AeroSense Symposium, 

Orlando, FL, April 2001, 4365-25. 

9. Hepner, D.; Hollis, M. S. L.; Mitchell, C. Yawsonde Technology for the Jet Propulsion 

Laboratory Free Flying Magnetometer Program; ARL-TR-1610; U.S. Army Research 

Laboratory: Aberdeen Proving Ground, MD, July 1998. 

10. Newill, J. F.; Burns, B. P.; Wilkerson, S. A. Overview of Gun Dynamics Numerical 

Simulations; ARL-TR-1790; U.S. Army Research Laboratory: Aberdeen Proving Ground, 

MD, July 1998. 

11. Whirley, R. G.; Engelmann, B. E. DYNA3D-A Nonlinear, Explicit, Three-Dimensional 

Finite Element Code for Solid and Structural Mechanics; UCRL-MA-107254, Rev. 1; 

Lawrence Livermore National Laboratory: Oak Ridge, TN, November 1993. 

12. Huang, X.; Newill, J. F. In-Bore Dynamic Analysis of the SCORPION Projectile; ARL-TR3048; U.S. Army Research Laboratory: Aberdeen Proving Ground, MD, September 2003.
27

13. Braun, W. F. The Free Flight Aerodynamics Range; BRL-R-1048; U.S. Army Ballistics 

Research Laboratory: Aberdeen Proving Ground, MD, July 1958. 

14. Hathaway, W. H.; Whyte, R. H. Aeroballistic Research Facility Free-Flight Data Analysis 

Using the Maximum Likelihood Method; AFATL-TR-79-98; Arrow Tech Associates: South 

Burlington, VT, December 1979. 

15. Arrow Tech Associates. ARFDAS: Ballistic Range Data Analysis System, User and 

Technical Manual; South Burlington, VT, May 1997. 

16. Solid Works Corporation. User Manual; Vol. 1, Concord, MA, 2001. 

17. Baumeister, T.; Avallone, E. Mark’s Standard Handbook for Mechanical Engineers, 8th 

ed.; Kingsport Press, Inc.: New York, 1979. 

18. Anderson, R. D.; Fickie, K. D. IBHVG2 – A Users Guide; U.S. Army Ballistics Research 

Laboratory: Aberdeen Proving Ground, MD, July 1987. 

19. Jitpraphai, T.; Costello, M. Dispersion Reduction of a Direct Fire Rocket Using Lateral 

Pulse Jets; ARL-CR-465; U.S. Army Research Laboratory: Aberdeen Proving Ground, MD, 

April 2001. 
NO. OF 

COPIES ORGANIZATION 

28

 1 DEFENSE TECHNICAL 

 (PDF INFORMATION CTR 

 ONLY) DTIC OCA 

 8725 JOHN J KINGMAN RD 

 STE 0944 

 FORT BELVOIR VA 22060-6218 

 1 US ARMY RSRCH DEV & 

 ENGRG CMD 

 SYSTEMS OF SYSTEMS 

 INTEGRATION 

 AMSRD SS T 

 6000 6TH ST STE 100 

 FORT BELVOIR VA 22060-5608 

 1 INST FOR ADVNCD TCHNLGY 

 THE UNIV OF TEXAS 

 AT AUSTIN 

 3925 W BRAKER LN STE 400 

 AUSTIN TX 78759-5316 

 1 DIRECTOR 

 US ARMY RESEARCH LAB 

 IMNE ALC IMS 

 2800 POWDER MILL RD 

 ADELPHI MD 20783-1197 

 3 DIRECTOR 

 US ARMY RESEARCH LAB 

 AMSRD ARL CI OK TL 

 2800 POWDER MILL RD 

 ADELPHI MD 20783-1197 

 3 DIRECTOR 

 US ARMY RESEARCH LAB 

 AMSRD ARL CS IS T 

 2800 POWDER MILL RD 

 ADELPHI MD 20783-1197 

ABERDEEN PROVING GROUND

 1 DIR USARL 

 AMSRD ARL CI OK TP (BLDG 4600) 
NO. OF NO. OF 

COPIES ORGANIZATION COPIES ORGANIZATION

29

 3 DARPA TTO 

 S WALKER (2 CPS) 

 A MORRISH 

 3701 FAIRFAX DR 

 ARLINGTON VA 22203 

 1 DARPA ATO 

 D HONEY 

 3701 FAIRFAX DR 

 ARLINGTON VA 22203 

 7 GEORGIA TECH RESEARCH 

 INSTITUTE 

 J MCMICHAEL (5 CPS) 

 K MASSEY 

 A LOVAS 

 7220 RICHARDSON RD 

 SMYMA GA 30080 

 1 OFFICE OF THE DIR OF DEFENSE 

 RESEARCH AND ENGRG WEAPONS 

 DUSD/S&T-DDR&E/WEAPONS 

 P MORRISON 

 1777 N KENT ST 

 ` STE 9030 

 ROSSLYN VA 22209 

 1 US ARMY RESEARCH OFFICE 

 T L DOLIGALSKI 

 PO BOX 12211 

 RESEARCH TRIANGLE PK NC 

 27709-2211 

 1 AIR FORCE RESEARCH LAB 

 MUNITIONS DIR 

 AFRL/MNAV 

 G ABATE 

 101 W EGLIN BLVD 

 STE 219 

 EGLIN AFB FL 32542 

 1 OREGON STATE UNIV 

 DEPT OF MECHL ENGRG 

 M COSTELLO 

 CORVALLIS OR 97331 

 1 CDR 

 US ARMY ARDEC 

 AMSTA AR CCH 

 S MUSALI 

 PICATINNY ARSENAL NJ 07806-5000 

 2 CDR 

 US ARMY TANK MAIN 

 ARMAMENT SYSTEM 

 AMCPM TMA 

 D GUZIEWICZ 

 C LEVECHIA 

 PICATINNY ARSENAL NJ 07806-5000 

 1 CDR USARDEC 

 AMSTA AR CCH A 

 M PALATHINGAL 

 PICATINNY ARSENAL NJ 07806-5000 

 1 CDR US ARMY RES OFFICE 

 AMXRO RT IP TECH LIB 

 PO BOX 12211 

 RESEARCH TRIANGLE PK NJ 

 27709-2211 

 3 ARROW TECH ASSOC INC 

 R WHYTE 

 A HATHAWAY 

 H STEINHOFF 

 1233 SHELBOURNE RD STE D8 

 SOUTH BURLINGTON VT 05403 

ABERDEEN PROVING GROUND

 24 DIR USARL 

 AMSRD ARL HR SD 

 T MERMAGEN 

 AMSRD ARL WM B 

 J NEWILL 

 R COATES 

 AMSRD ARL WM BA 

 G BROWN 

 B DAVIS 

 T HARKINS 

 T KOGLER 

 D LYON 

 S WANSACK 

 M WILSON 

 AMSRD ARL WM BC 

 B GUIDOS 

 S SILTON 

 P PLOSTINS (5 CPS) 

 J SAHU 

 D WEBB 

 P WEINACHT 

 AMSRD ARL WM BF 

 R PEARSON 

 S WILKERSON 
NO. OF 

COPIES ORGANIZATION 

30

 AMSRD ARL WM EG 

 E SCHMIDT 

 AMSRD ARL WM TC 

 R SUMMERS