bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unsteady Analysis of Particle-Laden Gas Flows When Hit by a Moving Shock Wave
Authors: Park Jun Sung , Baek Seung Wook 
Published: November 2021

Abstract
A successful prediction of the thermo-fluid mechanical characteristics of gas and particles is very crucial and imperative for the successful design and operation of rocket nozzles and energy conversion systems. This paper describes an interaction phenomenon when a moving shock wave hits a two-phase medium of gas and particles. A particle-laden gas is considered to be located along a ramp so that numerical integration is accomplished from the tip of ramp for a finite period. For the numerical solution, a fully conservative unsteady implicit 2nd order time-accurate sub-iteration method and a 2nd order Total Variation Diminishing (TVD) scheme are used with the finite volume method (FVM) for gas phase. For particle phase, the Monotonic Upstream Schemes for Conservation Laws (MUSCL) as well as the solution of the Riemann problem for the particle motion equations is used. Transient development of thermo-fluid mechanical characteristics is calculated and discussed by changing the particle mass density and particle specific heat. Major results reveal that when the particle mass density is smaller, there is a stronger interaction between two phases so that the velocity and temperature differences between two phases more rapidly decrease. When the particle specific heat is varied, only a thermal effect (temperature difference between gas and particles) is observed while the other effects (variations of particle concentration and velocity fields) are minor.
Critical Heat Flux During Reflood Transients in Small Hydraulic Diameter Geometries
Authors: Holowach M. J. , Hochreiter L. E. , Cheung F.-B. , Aumiller D. L. 
Published: November 2021

Abstract
Critical Heat Flux (CHF) at a low flow condition in a small hydraulic diameter duct is an important phenomenon for a MTR/ATR (Materials Test Reactor/Advanced Test Reactor) design under a number of accident conditions including reflood transients. Current CHF models in the literature, such as the Mishima/Nishihara and Oh/Englert CHF models, are based on macroscopic system parameters and not local thermal hydraulic conditions. These macroscopic parameter-based models cannot be readily used for analysis in transient best-estimate thermal hydraulic codes. This investigation focuses on developing a low flow rate CHF correlation, based on local conditions, that is amenable to implementation into a best-estimate transient thermal hydraulic code for a small hydraulic diameter channel. The model development proceeds with a means of correlating CHF data to local conditions parameters and then applying a correction factor to the resulting correlation, that permits accurate predictions over a range of pressures. An evaluation of the proposed local conditions-based CHF model is conducted by predicting independent sets of CHF experimental results over a range of flow rate, pressure, and sub cooling conditions. Conclusions on the viability of the proposed CHF model and suggestions for future efforts in improving the reflood heat transfer CHF models for small hydraulic diameter ducts are provided with an evaluation of the model results.
Two-Phase Flow in Microchannels
Authors: Hetsroni G. , Mosyak A. , Segal Z. 
Published: November 2021

Abstract
Experimental investigation of a heat sink for electronics cooling is performed. The objective is to keep the operating temperature at a relatively low level of about 323–333K, while reducing the undesired temperature variation in both the streamwise and transverse directions. The experimental study is based on systematic temperature, flow and pressure measurements, infrared radiometry and high-speed digital video imaging.
The heat sink has parallel triangular microchannels with a base of 250μm. According to the objectives of the present study, Vertrel XF is chosen as the working fluid. Experiments on flow boiling of Vertrel XF in the microchannel heat sink are performed to study the effect of mass velocity and vapor quality on the heat transfer, as well as to compare the two-phase results to a single-phase water flow.
Void Fraction Physics Resulting From Chaos Control of Upward Gas-Liquid Slug Flow
Authors: MacMeccan Robert M. , Langford Heather M. , Beasley Donald E. 
Published: November 2021

Abstract
The present investigation examines open-loop control of chaotic upward gas-liquid slug flow. Though highly structured, slug flow is deterministically chaotic in nature. Recent analytical and experimental investigations indicate that perturbation of a system parameter has the potential to reduce or increase chaos in a system. Slug flow provides an interesting medium for the investigation into control of chaotic systems due to its high degree of structure and complex physics. The response of slug flow under control in turn lends insight into its complex dynamics. The results of the present study validate open-loop control, showing that periodic perturbation of the air inlet conditions at a specific frequency destabilizes dominant system dynamics, pushing the system to less stable orbits with different flow physics.
Bubble Nucleation on Micro Line Heaters
Authors: Lee Jung-Yeop , Park Hong-Chul , Kwak Ho-Young , Jeon Jin-Seok 
Published: November 2021

Abstract
Nucleation temperatures on the micro line heaters were measured precisely by obtaining the I-R (current-resistance) characteristic curves of the heaters. The bubble nucleation temperatures on the heater with 3 μm width are higher than the superheat limit, while the temperature on the heater with broader width of 5 μm are considerably less than the superheat limit. The nucleation temperatures were also estimated by using the molecular cluster model of bubble nucleation with effect of contact angle. The bubble nucleation process was observed by microscope / 35 mm camera unit with a flash light of μs duration.
Behavior of Single Bubble Growth With Constant Wall Temperatures Controlled by a Microscale Heater Array
Authors: Lee Hanchoon , Son Younggeun , Oh Byung Do , Bae Sungwon , Kim Moohwan 
Published: November 2021

Abstract
Experiments of nucleate pool boiling of R11/R113 mixtures were performed. The heat flux was measured with sufficient temporal and spatial resolution to show characteristics of the nucleate boiling with constant wall temperatures controlled by a novel microscale heater array. Instantaneous images of single bubbles were captured using a high-speed CCD camera, synchronized with the data acquisition from the microscale heater array. The heater was 0.27 × 0.27mm2, which is similar to the size of a typical bubble in nucleate boiling. The heating power was designed to automatically maintain a constant wall temperature. The experiments were performed with wall superheat using pure substances and mixtures with different mass ratios of R11 and R113. For pure substances, the bubble growth rate was much lower with the constant wall temperature than that with the constant wall heat flux. A high rate of bubble growth initially was observed for pure substances. The volume growth rate decreased for large bubbles when the wall temperature was constant, but increased continuously for a constant wall heat flux. The rate of bubble growth in mixtures is highly dependent on the mass fraction of their components. The peak value of the heat flux for mixtures is reduced because of concentration gradients at the bubble interface. A numerical simulation was also performed; qualitative agreement was noted between the numerical and experimental results.
New Phenomena of Mass Transfer in Gas/Liquid Flows
Authors: Bork O. , Schlueter M. , Scheid S. , Raebiger N. 
Published: November 2021

Abstract
Due to a lack of knowledge of mass transfer in multiphase flows, investigation into mass transfer is in great demand in order to obtain a better understanding of local phenomena. This paper describes the experimental investigation into mass transfer, in particular the influence of flow conditions around bubbles, contact time between phases, bubble size and viscosity of the liquid. Single bubbles are injected into a bubble column (diameter dR = 100 mm). The laser-induced fluorescence measuring technique (LIF) is used to visualize the concentration field around a freely rising bubble. A special experimental set-up has been developed which permits a three-dimensional (3d) reconstruction of the local concentration field around bubbles. Oxygen concentration fields of ellipsoid gas bubbles with equivalent diameters between 4mm and 8mm in aqueous solutions are shown and local mass flows are presented.
Mechanistic Model for Dynamic Forces in Micro-Drilling
Authors: Gong Yongping , Ehmann Kornel F. 
Published: November 2021

Abstract
By considering the effects of drill grinding errors and drill deflections, dynamic cutting chip thickness models were developed which in combination with workpiece surface inclination effects allowed the formulation of expressions for the dynamic cutting chip cross-sectional area. By using the dynamic chip thickness and dynamic cutting chip area to replace their static counterparts, static drilling force models were extended to facilitate the prediction of dynamic cutting forces in micro-drilling processes. The geometric characteristics of micro-drills were considered in these mechanistic force models. Separate thrust, torque and radial force models for the major cutting edges, secondary cutting edge and for the indentation zone were developed. The effects of drill installation errors on the radial cutting forces acting on the chisel edge and the major cutting edges were also included.
Analytical Convolution Model of Cutting Forces in 3-D Ball End Milling
Authors: Chiou Richard Y. , Zhao Bing 
Published: November 2021

Abstract
This paper presents an analytical convolution model of dynamic cutting forces in ball end milling of 3-D plane surfaces. The model takes into account the instantaneous slope on a sculptured surface to establish the chip geometry in cutting force calculation algorithm. A three-dimensional model of cutting forces in ball end milling is presented in terms of material properties, cutting parameters, machining configuration, and tool/work geometry. Based on the relationship of the local cutting force, chip load and engaged boundary, the total cutting force model is established via the angle domain convolution integration of the local forces in the feed, cross feed, axial direction, and inclination angle. The convolution integral leads to a periodic function of cutting forces in the angle domain and an explicit expression of the dynamic cutting force components in the frequency domain. Following the theoretical analysis, experimental study is discussed to illustrate the implementation procedure for force identification, and frequency domain data are presented to verify the analytical results.
An Investigation of the Predicting Capabilities of a Variable Flow Stress Machining Theory
Authors: Mathew P. 
Published: November 2021

Abstract
The Oxley Machining Theory, which has been developed over the last 40 years, is presented in this paper. The capability of the model is described with its initial two-dimensional machining approach followed by the extension to the generalised model for three-dimensional machining. The theoretical results from the model are compared with the experimental results to determine the model capability. A brief description of the work associated with the effect of strain hardening at the interface is presented and comparative results are shown. A further extension of the model to intermittent cutting process of reaming is also presented and a comparison with the experimental results indicates the model developed is quite capable of predicting cutting forces for reaming. In explaining the results obtain, the assumptions made are explained and the inputs required. The limitations of the modelling approach are presented. It is pointed out that the Oxley model is a versatile model as long as proper description of the material flow stress properties is presented.
Modeling of Necking/Shear Failure of Aluminum Sheet Metals With Consideration of Void Nucleation and Growth
Authors: Chien W. Y. , Pan J. , Tang S. C. 
Published: November 2021

Abstract
Failure of two aluminum sheets, AA5754 and AA6111, under stretching conditions is analyzed using a combined plane stress and plane strain approach. The sheet material is modeled by an elastic-viscoplastic constitutive relation that accounts for material plastic anisotropy, material rate sensitivity, and the softening due to the nucleation, growth, and coalescence of microvoids. Failure processes of sheet metals are modeled under plane strain tension. Also, failure strains are determined under bending conditions when the necking mode is suppressed. The results are consistent with experimental observations where the failure strain of the aluminum sheets increases significantly under bending conditions. The results indicate that when a considerable amount of necking is observed under stretching conditions, failure strains under bending conditions are higher.
Pressure Generated During Pulse Electrochemical Machining
Authors: Kozak J. , Rajurkar K. P. 
Published: November 2021

Abstract
Pulse electrochemical machining (PECM) provides an economical and effective method for machining high strength, heat-resistant materials into complex shapes such as turbine blades of titanium alloys. The dimensional accuracy of PECM can be improved if a small interelectrode gap is maintained. This paper presents an interelectrode gap model for estimating pulse pressure generated after pulse current switched on, and the subsequent dynamic loading on the electrodes during PECM. A specially built PECM cell and a high-speed data acquisition system are used to measurement of wave pressure for verification of estimated values.
Industry-University Educational Partnerships for the New Millennium: Experiences and Lessons Learned
Authors: Wiens Gloria J. , Grider David C. , Beale David G. , Magleby Spencer P. , Todd Robert H. , Pugh Len , Stanfill R. Keith , Coulter John P. , Gillette Frank C. , Franco James S. , Mattson Christopher A. , Clerc Jean-Philippe , Riger Hannah 
Published: November 2021

Abstract
Selected as one of the 2001 ASME / IMECE industrial highlight sessions, this panel focuses on the paradigm shift from the traditional capstone design course structure towards new design experiences formulated through industry-university educational partnerships. Such partnerships feature collaboration of multidisciplinary student, faculty and industrial teams for product and process realization. The two-session symposium addresses the following topics:
• Integrated product and process design
• Modern design methodologies integration
• Frameworks for university and industrial partnerships
• Recruitment, student profiles, graduation and placement
• Effective evaluation of student, team and project
• Grading and motivation techniques
• Program assessments and outcomes
• Implementation, institutionalization, and sustainability strategies
The ten-person panel brings together a group of faculty, program administrators, students and industrial sponsors from three different undergraduate engineering programs incorporating the new industry-university educational partnerships. The panel discussion highlights the attributes, pros/cons, obstacles/challenges, lessons learned, intellectual property issues, project failure drivers, role of industrial liaisons, recruitment, the effect on faculty and student participants, and program outcomes. The university programs represented are Brigham Young University, University of Florida, and Lehigh University.
The symposium organizers extend many thanks to the panelists and session chairs for providing the program content and energized discussions required for making this panel and symposium a success. Last but not least, R. Keith Stanfill’s continual behind-the-scenes leadership and assistance in bringing together the key elements of the program is greatly appreciated.
Issues and Directions of MEMS Research for the Electronics Industry
Authors: Pak Y. Eugene 
Published: November 2021

Abstract
The 20th Century has witnessed breathtaking developments in the miniaturization and the large-scale integration of microelectronic devices that have had an enormous impact on human affairs. The same miniaturization paradigm can be applied to mechanical devices using MEMS technology leading to ultra small micromachines that cannot otherwise be fabricated using conventional machining and assembly techniques. The MEMS technology is expected to have a great impact in the 21st century by enabling many complex electromechanical systems to be fabricated and integrated. In this paper, applications of MEMS to many areas relating to information and biotechnology are discussed. These topics are presented in the context of ongoing research at the Samsung Advanced Institute of Technology (SAIT). SAIT is the central research laboratory for the Samsung Corporation whose charter is to develop breakthrough technologies to be th leader in the 21st century.
Characterization of a Piezoelectric Membrane for MEMS Power
Authors: Bruce K. , Richards R. , Bahr D. , Richards C. 
Published: November 2021

Abstract
Work toward the development of a thin-film piezoelectric membrane generator is presented. The membrane generator is the central component of a new MEMS power generation system, the P3 micro power system. The P3 micro power system is based on a two-dimensional, modular architecture, in which the individual generic modules or unit cells each have all the functions of an engine integrated. Each unit cell is an external combustion engine, in which thermal power is converted to mechanical power through the use of a novel thermodynamic cycle that approaches the ideal vapor Carnot cycle. Mechanical power is converted into electrical power through the use of a thin-film piezoelectric membrane generator. This paper introduces the concept of the thin-film piezoelectric membrane generator, and describes its design and fabrication. Results of a study to characterize the performance of the piezoelectric membrane generator under expected operating conditions are presented. Current prototypes of the membrane generator are shown to be capable of producing a peak power of 0.1 milliWatts at a voltage of 0.5 Volts.
Multiplexed Detection of Nanoscale Microcantilever Deflections for High-Throughput Biomolecular Analysis
Authors: Dames Chris , Wu Guanghua , Lin Henry , Majumdar Aran 
Published: November 2021

Abstract
We present the first steps towards a device for the parallel detection of multiple biomolecules through the binding-induced deflection of microcantilevers. In this study the thermal bimorph effect is used to model the changes in surface stress that are caused by molecular binding. A bank of five cantilevers (each 600 μm long, 645 nm thick) is actuated thermally over a range of 3 μm of tip deflection. The cantilevers are illuminated with a laser and the resulting pattern of reflected spots is used to validate a new CCD-based detection method that tracks the deflections of multiple cantilevers simultaneously. A stress-balancing fabrication technique was also implemented to reduce the initial deflection by an nearly order of magnitude.
Design of Deformable Focusing Micromirrors
Authors: Yen Hanchee , Lee Chimin , Chen Rongshun , Lin Meng-Ju 
Published: November 2021

Abstract
A deformable mirror is an adaptive optical device that can deform its surface shape to self-adjust its focal length. This paper designed a center-anchored circular deformable micromirror, which is a two-layer structure; a metal layer atop a structure layer, fabricated using surface micromachining process and actuated by electrostatic force.
A series of simulations are performed to investigate the process- and voltage-induced deformations and thus to determine the focal length under various parameters for the designed micro-mirror. Because of warpage occurring after release, the two-layer center-anchored circular plate was cut into several sectors when fabricated, in which the diameters of the circular plate and the centric anchor are 500 (before deformation) and 100 μms, respectively. The profiles of deformable mirror are measured and the curvature radius measured is estimated from 200 to 400 μm.
Modeling and Optimization of a High Sensitivity Out-of-Plane Microgyroscope
Authors: Li Shifeng , Chen Shaochen 
Published: November 2021

Abstract
This paper presents an optimal model for microgyroscope design. According to gyroscope topology, one lumped dynamic model is built to optimise the microgyroscope performances. The design parameters are categorized into function variables and style variables to reduce optimisation cost. The maximum sensitivity and minimum area of the device are selected and weighted as the combined multiple objective functions. The optimisation is conducted with a solver in Excel9.5™. FEM is chosen to verify these optimised results. The FE results show good agreement with the model calculation. The discrepancy of mode shape is less than 5%. The discrepancy of sensitivity is less than 3%. The output linearity is less than 1.5%.
Characterizing the Poisson’s Ratio of Thin Films Using Resonance Method
Authors: Tsai Hsin-Chang , Lai Wen-Pin , Fang Weileun 
Published: November 2021

Abstract
In this study, we proposed a new and simple technique to characterize the Poisson’s ratio of thin films. The diagnostic micromachined cantilevers are fabricated using the thin film to be determined. The Poisson’s ratio of the thin film can be determined after the bending and torsional vibration modes are measured. To obtain cantilevers with prismatic cross section, the micromachined beams were fabricated on the (111) silicon substrate. The primary advantage of this technique is that the error of Poisson’s ratio due to the deviation of film thickness can be significantly reduced. In application of this technique, the Poisson’s ratio of thermally grown silicon dioxide is measured to be 0.26± 0.01.
Creation of Nanometer-Sized Features in Polysilicon Using Fusing
Authors: Levitan Jeremy A. , Good Dan , Sinclair Michael J. , Jacobson Joseph M. 
Published: November 2021

Abstract
Current microfabrication systems can achieve resolutions of approximately 0.1μm. We present physical methods for creating structures with length scales and characteristic dimensions significantly below current fabrication resolutions. These structures, themselves fabricated in conventional, gross-resolution (greater than 2μm) semiconductor facilities, undergo structural change to create features below the lithography limits of the fabrication process.
These devices — dog-boned microfabricated polysilicon fuses — are heated just below melting, and a small perturbation current heats a narrow, necked region of the beam, resulting in fusing.
Infrastructure has already been constructed to create gross-resolution structures in microfabrication. Novel processes and mechanisms are needed to utilize these resolutions and create structures capable of addressing biological systems, functioning quantum mechanically, use single electrons, or require extreme speeds.
Experimental Study on Roughness Effect for Laminar Micro-Channel Gas Flow
Authors: Tu Jih-Hsing , Tseng Fangang , Chieng Ching-Chang 
Published: November 2021

Abstract
Present study investigates the roughness effect on laminar gas flow for microchannels ranging from 40 to 600 μm with various roughness heights (40–82 nm) by systematical experiments. The micro-channels are manufactured by micro-machining technology and KOH anisotropic etching is employed to achieve various roughness patterns. Experimental results shows that higher product levels of Reynolds number (Reh) and friction factor (f) are obtained for microchannels of larger size and smaller relative roughness and friction factor f approaches to laminar flow theory value f0 for very smooth channel but the ratio of (f/f0) decreases as the surface roughness increases.