# Presentation: 285434

## Current Airframe Emissions Research

- Richard Antcliff
- NASA Langley Research Center

## }

**40,000 ft**

**3000 ft**

**Stratosphere:**
**  • ****NO****x**

**Ozone Layer Depletion**

**Troposphere:**
**  • ****CO****2**
**  • ****No****x**
**  • ****H****2****O Vapor**
**  • ****Aerosols**
**  • ****Particulates**

**Green House Gasses**

**Cloud Formation**

**Global Warming**

**Ground Level:**
**  • ****No****x**
**  • ****VOC’s**
**  • ****CO**
**  • ****Particulates**

**Ozone & Smog Formation**

**Health Effects**

**Local Air Quality**

**Environmental Impacts of Aircraft Emissions**

- Stan Husch - NASA Langley

## Generic Program Strategy

***Systems Technology Programs***
** ****• ****Pursues and matures promising, high-payoff technologies**
** • ****Aligned with critical issues to achieving stretch goals**
** • ****Includes decision points (    ) to provide opportunities to integrate key technologies developed**
**   ****within the Base R&T program and to strategically revector program**

***Base Research & Technology Plan***
** • ****Pursues broader mix of long-term, high-risk/high-payoff technologies**
** • ****Tackles fundamental and “barrier” issues**
** • ****Aligned with critical issues to achieving stretch goals**
** • ****Transition technologies to Systems Technology Programs and directly to the customer**
** • ****Provides basis for future Systems Technology programs**

***Today***
- Because we don’t know
- how to achieve the
- Stretch Goals today, we
- need a combination of
- Base R&T and Systems
- Technology Programs
- to credibly manage the
- process of achieving
- the goals

*Base R&T*

*S.T. 1*

*S.T. 2*

*S.T. **11*

***Generic Program Strategy***

***20 Years***
***Stretch Goal***

***10 years***

***Stretch Goal***

## Airframe Systems Base FY 99

**ASCOT**

**Morphing**

**TAME**

**MAD**

**ATTAC**

**CLOSUR**

**ACE**

**FACT**

**IAS**

**Error-**

**Proof**

**AAA**

**RACR**

**Hyper-X**

**Increase **

**Safety**

**Reduce **

**Emission**

**Reduce **

**Noise**

**Increase **

**Capacity**

**Reduce **

**Cost**

**Reduce **

**Travel **

**Time**

**Invigorate **

**General **

**Aviation**

**Design **

**Cycle & X-**

**Planes**

**Reduce **

**Cost to **

**Orbit**

**Reduce **

**Cost to **

**Space**

**Enabling **

**Technology**

**DoD **

**Synergy**

**Primary**

**Secondary**

**Support**

**Access to **

**Space**

**Three **

**Pillars for **

**Success**

**Enterprise **

**Goal**

**Global Civil Aviation**

**Revolutionary **

**Technology Leaps**

**Level 2 Projects - FY99**

## Innovative High Lift

**Innovative High Lift**

**Polymers (LaRC-SI)**

**Actuators (THUNDER)**

**Active Flow Control**

**Advanced High Lift**

*Reduce Cost*
*of Air Travel*

**Accomplishments**

**Demonstrated operational lifetimes > 10 million cycles for high displacement piezoelectrics**
**Developed computational models to simulate polymer response to electric fields**
**Developed vortex-on-demand device to produces vortices comparable to conventional devices**

## DARPA/AFRL/NASA Smart Wing Program

_**Program Objectives:**_
**Use smart materials and structures to improve military aircraft aerodynamic performance in lift to drag (L/D) ratio, maneuver capabilities and aeroelastic response**
**Phase I: focus on static wing-shaping concepts **
**Wing twist**
**Hingeless control surfaces**
_**Approach:**_
**Design, fabricate and test semi-span models**
**Address power, reliability, system integration **
**Lay the ground work for follow-on program(s)**

**Hingeless Control Surface Concept**

_**State of the Art:**_
**Performed small-scale demonstrations of smart material actuator wing-shaping concepts.**
**This effort is the largest-scale wind-tunnel demonstration of smart material actuator wing-shaping concepts to date.**

## Adaptive Refinement Based on Smoothing Element Analysis

- Mesh 0

- Mesh 1

- Mesh 4
- Max error < 30% of Initial Mesh 0

- Uniform End-Shortening

- Uniform End-Shortening

- Symmetry

- Symmetry

- Internal Pressure
- Loading of 18.2 psi

**Adaptive Refinement Based on Smoothing Element Analysis**
**And Residual Error Estimation for Built-up Aerospace Structures**

-   Adaptive Refinement of Boeing Crown Panel:
-    Residual-Based Error Distribution and Mesh Refinement

## Integrally Stiffened Metallic Fuselage Structure

- <date/time>

- Integrally stiffened curved fuselage panel machined from aluminum alloy 7050 plate

**Integrally Stiffened Metallic Fuselage Structure**

- Curved compression test panel
- machined from 7050 plate

- Integrally stiffened aluminum
- alloy 6013 extrusions

- 118” Radius

- Integral “Zee” Stiffners

- 48” x 78” Test Panel

## Integrally Stiffened Metallic Fuselage Structure

**Notes:**
Issue Addressed:
 Integrally stiffened structure must demonstrate durability and damage tolerance equivalent to or better than conventional built-up structure.  The structure must be able to contain a fracture while subjected to combined loads typical in a pressurized fuselage.  The industry “two-bay fracture criterion” requires the structure to support limit load with a two-bay long crack present.

Results: 
Machined integrally stiffened curved fuselage panels were tested under simulated fuselage loading conditions.  Panels contained either a circumferential or longitudinal crack.  Photos show the machined panel and test fixture to evaluate the longitudinal crack case.  Panel is 60” x 120”, with membrane 0.063”, radius of curvature 127”, machined from 7475. (7475 used as it is expected to have more isotropic fracture properties than 7050 shown on prior chart).  The panel has machined stringers and pad-up areas with riveted frames.  Panel was precracked under cyclic loading at 8.6 psi to a crack length of 38”.  Panel then loaded by increasing pressure.  Rapid crack extension occurred at about 9.7 psi and the crack arrested at rivets that attach the frames. Final crack length was approx. 40”, equal to a two-bay crack length.  The panel was further loaded to 10.3 psi (limit of test fixture) with no further crack extension.  Limit load occurs at about 9.8 psi.  These results indicate that an integrally stiffened structure can support limit load with a two bay crack length.

## Solution-adaptive Unstructured Grid CFD Solver

**Benefits of Solution-adaptive Grid**
- Grid generation time reduced from days to hours
- Virtually eliminate human intervention
- Improved accuracy, grid locations derived from physics
- Codes run by designer engineers, not CFD experts

**Structured**
**Grid**

**Unstructured**
**Grid**

***Adaptive***
***Grid***

**20 Days**

**5 Days**

**X Hours**

**75%**
**Reduction**

- Adapted grid clusters grid
- points to high gradient regions
- and produces correct solution
- of vortex bursting

- M = 0.4,  = 20 ̊

## Innovative High Lift

**Innovative High Lift**

**Polymers (LaRC-SI)**

**Actuators (THUNDER)**

**Active Flow Control**

**Advanced High Lift**

_**Accomplishments**_

- Demonstrated operational lifetimes > 10 million cycles for high displacement piezoelectrics
- Developed computational models to simulate polymer response to electric fields
- Developed vortex-on-demand device to produces vortices comparable to conventional devices

## RevCon Program

**BIOMEMETICS!**