| Physics and Modeling of Compound SemiConductor Devices with Semi- Insulating and Native-Oxide Layers |
31 DEC 2000 |
20 pages |
| Authors:
H. L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
 | In looking at the literature the two primary sources for two- dimensional calculations that were found were Chin et. at and Poncet. Both of these investigators essentially solve the same set of governing equations. Chin solved a similar problem to that addressed above, but the computational domain was limited to the oxide only. No calculation was performed in either the virgin material or the mask. Poncet's problem is somewhat different ... |
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| Transient Transport in Nanostructure Devices Via The Quantum Liouville Equation In The Coordinate Representation |
JUN 2000 |
24 pages |
| Authors:
H. L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This document summarizes work performed under US Navy, Office of Naval Research Contract: N00014-95-C-0024 to examine transient transport in quantum structures via the quantum Liouville equation in the coordinate representation. For comparison transient results via the Wigner distribution are included. The issue of dissipation in nanostructures was also initiated in this study. A summary of the dissipation results is included in a reprint. |
|
| High Speed Quantum Device and Circuits: Modeling and Design. Phase 1 |
NOV 1999 |
35 pages |
| Authors:
H. L. Grubin; R. C. Buggeln; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This document summarizes work carried out under a U.S. Navy SBIR study, Topic N99-02. The goal of the study was to develop a robust, portable, user-friendly, validated quantum device algorithm for designing tunneling devices, in particular resonant tunneling devices, for realistic present, near future and future applications. Successful algorithm development based on the space and time dependent Wigner equation was undertaken with the result that ... |
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| Transient Transport in Nanostructure Devices via the Quantum Liouville Equation in the Coordinate Representation |
JUN 1999 |
13 pages |
| Authors:
H. L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Through the use of numerical methods the quantum Liouville equation in the coordinate representation has been implemented for the study of semiconductor devices with nanoscale feature sizes, with an emphasis on dissipation. We have successfully applied this algorithm to the calculation of current in single and multiple barrier diodes, and Scientific Research Associates, Inc. is presently one of the few research organizations numerically obtaining the quantum distribution functions for both ... |
|
| Transport Phenomena Studies by Computational Simulation in Structural Materials Processing |
SEP 1998 |
46 pages |
| Authors:
R. C. Buggeln; M. Meyyappan; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Chemical vapor deposition (CVD) is one of the most important techniques for the processing of structural materials. It is extremely versatile in that a wide range of materials and coatings is done by CVD, perhaps more than by any other technique. The process is flexible enough to accommodate a variety of sizes and shapes of objects to be processed and allow continuous change of composition of the ... |
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| Scientific and Engineering Semiconductor Device Simulation Tools as a Windows Application |
01 APR 1998 |
6 pages |
| Authors:
H. L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| A bottleneck associated with numerical simulations of quantum feature size semiconductor devices, has been the absence of a menu driven program that does not require user knowledge of the solution algorithm for the device equations. Under this SBIR study SRA transferred quantum transport algorithms, originally developed for supercomputer simulations to a PC environment. This resulted in (1) program execution via menu based MMicrosoft Windows-type interface, (2) user-defined parameters (dimension, doping, ... |
|
| Numerical Studies of Physics and Operation of LTG Materials and Devices |
AUG 97 |
31 pages |
| Authors:
Harold L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This document summarizes Scientific Research Associates, Inc., (SRA) low temperature material studies, carried out under U.S. Air Force Office of Scientific Research (AFOSR) Contract F49620-94-C-0024. The study summarizes a model that was developed that is consistent with present low temperature growth (LTG) experimental studies. SRA's study included one-dimensional transient simulations and two-dimensional time independent constrained geometric studies. The broad aspects of the study indicate that annealed LTG GaAs is best ... |
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| Numerical Studies of the Physics and Operation of LTG Materials and Devices |
AUG 97 |
31 pages |
| Authors:
Harold L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This document summarizes Scientific Research Associates, Inc., (SRA) low temperature material studies carried out under U.S. Air Force Office of Scientific Research (AFOSR) Contract F49620-94-C-0024. The study summarizes a model that was developed that is consistent with present low temperature growth (LTG) experimental studies. SRA's study included one dimensional transient simulations and two dimensional time independent constrained geometric studies. The broad aspects of the study indicate that annealed LTG GaAs ... |
|
| A Process Model and Complementary Experiments for the Electron Cyclotron Resonance (ECR) Technology: Application to Deposition and Etching. Phase II |
DEC 96 |
106 pages |
| Authors:
M. Meyyappan; T. R. Govindan; F. deJong; R. C. Buggeln; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This Phase II SBIR project was undertaken to model the Electron Cyclotron Resonance (ECR) based plasma processing with a view to understanding plasma mechanisms and aiding in process and equipment design. Models of various complexity levels were successfully developed and applied to ECR discharges. The computer codes were used to study the effects of flow rates, pressure, microwave power and reactor geometry parameters on the process figures of merit. This ... |
|
| Transport Phenomena Studies, VIA Computational Simulation, in Structural Materials Processing |
07 JUN 95 |
72 pages |
| Authors:
SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The objective of the present STTR project is to develop computational tools necessary to simulate processing of structural materials. Processes considered are chemical vapor deposition (CVD) and chemical vapor infiltration In the Phase I work discussed in this report, an existing SRA computational fluid dynamics code has been adapted to apply to CVD modeling. Multicomponent diffusion, thermal diffusion, homogeneous and surface reactions and conjugate heat transfer have been included. A ... |
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| Opto-Electronic Components from Non-Stoichiometric III-V Materials |
28 FEB 95 |
31 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| An investigation was undertaken to determine the feasibility of integrating low temperature growth GaAs:As and silicon for the development of optoelectronic devices. These devices attempt to exploit the optoelectronic properties of LT GaAs while integrating the structure on silicon substrates. Numerical models of LT GaAs are developed and implemented to aid in the design of such devices. An integrated MSM-LED structure was successfully fabricated on a silicon substrate. The results ... |
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| Design and Development of Low Noise, High Speed, High Electron Mobility Transistors (HEMTs) |
SEP 94 |
125 pages |
| Authors:
J. P. Kreskovsky; H. L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| An investigation was undertaken to design and fabricate low noise, high speed InP-based HEMTs. The investigation consisted of several components: the development of quantum corrected hydrodynamics simulation codes; application of these codes to aid in design and optimization of HEMTs for low noise, high speed operation; and fabrication and testing of the resulting designs. Through the research effort, HEMTs of previously unobtained performance levels were designed and fabricated. These results ... |
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| Numerical Studies of Low Temperature Gallium Arsenide Buffer Layers and Their Influence on Device Operation |
17 JUN 94 |
36 pages |
| Authors:
Harold L. Grubin; John P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Through the use of numerical methods involving both the drift and diffusion equations including traps, and more recently the quantum Liouville equation, Scientific Research Associates, Inc., (SRA) has been examining the physics and operation of LTG materials and devices. Both defect and Schottky models have been studied, and two-dimensional microscopic and macroscopic device simulations have been performed. A new generalization of the drift and diffusion equations, including current, has been ... |
|
| Numerical Studies of Low Temperature Gallium Arsenide Buffer Layers and their Influence on Device Operation |
17 JUN 94 |
36 pages |
| Authors:
Harold L. Grubin; John P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Through the use of numerical methods involving both the drift and diffusion equations including traps, and more recently the quantum Liouville equation, Scientific Research Associates, Inc., (SRA) has been examining the physics and operation of LTG materials and devices. Both defect and Schottky models have been studied, and two-dimensional microscopic and macroscopic device simulations have been performed. A new generalization of the drift and diffusion equations, including current, has been ... |
|
| Large Signal Time Dependent Quantum Mechanical Transport in Quantum Phase Based Devices |
10 JUN 94 |
245 pages |
| Authors:
Harold L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This document summarizes studies performed under AFOSR Contract: F49620-91-C-0016. In this study equilibrium and nonequilibrium electron and hole transport in quantum scale structures were studied via solutions to the quantum Liouville equation in the coordinate representation The coordinate representation density matrix solutions are the first to provide the quantum distribution function for electrons and holes in nanoscale devices coupled to model dependent dissipation. Illustrations of the use of the algorithm ... |
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| Capacitance Calculations in Nanostructure Devices Via the Quantum Liouville Equation in the Coordinate Representation |
31 MAY 94 |
50 pages |
| Authors:
Harold L. Grubin; T. R. Govindan; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Through the use of numerical methods the quantum Liouville equation in the coordinate representation has been implemented for the study of semiconductor devices with nanoscale feature sizes. This document summarizes work performed under US Army Contract DAAL03-91-C-0035 to evaluate the significance of calculating the capacitance voltage characteristics of quantum structures via the quantum Liouville equation. All studies were to be performed with a user-friendly workstation based algorithm, copies of which ... |
|
| The Physics and Operation of Ultra-Submicron Length Semiconductor Devices |
MAY 94 |
95 pages |
| Authors:
SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This document summarizes activities under ONR Contract: N00014-86-C- 0780, under which equilibrium and nonequilibrium electron and hole transport in micron and submicron structures were studied via a wide range of numerical procedures. These included Monte Carlo methods, moments of the Boltzmann transport equation, Schrodinger's equation and the quantum Liouville equation in the coordinate representation. While all of the studies have resulted in a large collection of publications, the basic theme ... |
|
| Modeling of Quantum Transport in Semiconductor Devices (The Physics and Operation of Ultra-Submicron Length Semiconductor Devices) |
MAY 94 |
213 pages |
| Authors:
David K. Ferry; Harold L. Grubin; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The evolutionary decrease in the size of an individual semiconductor device continues with no apparent end of the process in sight. As a consequence, it is quite likely that critical dimensions will soon be comparable to quantum coherence lengths for the particles 'Involved in the transport within the device. Generally, quantum transport differs from semi-classical transport in the utilization of a quantum kinetic equation (as opposed to the Boltzmann transport ... |
|
| Fluid Dynamic Noise in a Centrifugal Pump |
AUG 93 |
110 pages |
| Authors:
D. G. Tse; J. H. Whitelaw; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Pressure distributions and frequency spectra have been obtained in a centrifugal pump having flow rates between the design point and near shut-down. The pump was comprised of a radial flow impeller with four backswept blades and a single volute. Measurements were obtained at the design flow rate and at off- design conditions to advance understanding of noise generation, to quantify the contribution of tonal, narrowband and broadband components to the ... |
|
| Numerical Studies of Low Temperature Gallium Arsenide Buffer Layers and Their Influence on Device Operation |
14 APR 93 |
18 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The focus of the program is the development and application of an algorithm for studying charge transport in low temperature gallium arsenide (LT GaAs) buffer layers and the influence of such layers on device operation. During this reporting period the drift and diffusion equations were modified to include the contributions of clusters in one and two dimensions. In addition, the effects of high resistance material on the operation of FETs ... |
|
| Projectile Base Bleed Technology. Part 1. Analysis and Results |
NOV 92 |
84 pages |
| Authors:
Howard J. Gibeling; Richard C. Buggeln; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Detailed finite rate chemistry models for H2 and H2-CO combustion have been incorporated into a Navier-Stoke computer code and applied to flow field simulation in the base region of an M864 base burning projectile. Results without base injection were obtained using a low Reynolds number k-e. turbulence model and several mixing length turbulence models The results with base injection utilized only the Baldwin-Lomax model for the projectile forebody and the ... |
|
| Projectile Base Bleed Technology; Part 2. User's Guide CMINT Computer Code, Version 5.04-BRL |
NOV 92 |
126 pages |
| Authors:
Howard J. Gibeling; Richard C. Buggeln; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Detailed finite rate chemistry models for H2, and H2-CO combustion have been incorporated into a Navier-Stokes computer code and applied to flow field simulation in the base region of an M864 base burning projectile. Results without base injection were obtained using a low Reynolds number k-epsilon turbulence model and several mixing length turbulence models. The results with base injection utilized only the Baldwin-Lomax model for the Projectile forebody and the ... |
|
| Numerical Studies of Low Temperature Gallium Arsenide Buffer Layers and Their Influence on Device Operation |
APR 92 |
12 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This report summarizes recent work on the development and application of an algorithm for studying charge transport in low temperature gallium arsenide (LT GaAs) buffer layers and their influence on device operation. During this reporting period the drift and diffusion equations were modified to include the transient dependence of electrons and holes for gallium arsenide. Calculations were performed for two-terminal, one and two-dimensional structures. Studies with the one-dimensional structures focussed ... |
|
| Active Control of Pressure, Sound and Velocity of Centrifugal Pumps |
MAR 92 |
117 pages |
| Authors:
D. G. Tse; J. S. Sabnis; H. McDonald; James H. Whitelaw; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Measurements of velocity, pressure and sound have been obtained in a centrifugal pump with a four blade impeller rotating at speeds between 1470 rpm and 3510 rpm to improve understanding of noise generation and to investigate the feasibility of reducing fluid dynamic noise with active control. The velocity results show flow separation in the region near the shroud wall and at the suction surface of the blades with the flow ... |
|
| Phenomena Unique to Sub-Micrometer Devices |
13 FEB 92 |
59 pages |
| Authors:
H. L. Grubin; T. R. Govindan; B. J. Morrison; F. J. De Jong; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| An algorithm developed to solve the time dependent Liouville equation in the coordinate representation was implemented to examine phenomena unique to submicron structure. Quantum transport of electrons and holes in III-V and II-VI resonant tunneling structures was investigated. Attention was focused on the tunneling in and out of quantum wells by both electrons and holes. It was determined that characteristic transients including tunneling and capacitive contributions was of the order ... |
|
| Numerical Simulation of the Function of Scientific Instrumentation for Measuring the Speed of Electron Devices |
13 FEB 92 |
113 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; W. R. Briley; G. A. Andrews; M. A. Osman; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Implementation of three algorithms, (1) moment equation, (2) Monte Carlo, and (3) quantum Liouville equation algorithms, were used in a program to determine the high speed and high frequency operation of submicron electron devices. For a psuedomorphic high electron mobility transistor, high frequency, small signal, subpicosecond charge density waves were observed to form within the two dimensional electron gas. Large signal operation of the PHEMT indicated that the switching time ... |
|
| Temperature Description of Transport in Single- and Multiple-Barrier Structures |
1992 |
5 pages |
| Authors:
H. L. Grubin; T. R. Govindan; B. J. Morrison; D. K. Ferry; M. A. Stroscio; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Barrier calculations based upon solutions of the Liouville equation in the coordinate representation reveal a complicated spatial dependence of the quantum distribution function near and within the barriers. Within the framework of classical transport this spatial dependence suggests equilibrium electron temperature values that differ from the ambient. The prospect of quantum heating and cooling under equilibrium conditions is examined and dispelled in favour of an interpretation that includes density-gradient contributions. ... |
|
| Design and Development of Low Noise, High Speed High Electron Mobility Transistors |
MAY 91 |
58 pages |
| Authors:
J. P. Kreskovsky; H. L. Grubin; B. J. Morrison; T. R. Govindan; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This report summarizes work performed under contract DAAL03-90-C- 0021. Under this study the moments of the Boltzmann Transport Equation were applied to investigate the performance of HEMT. The results of the simulations are compared to experimental measurements for a related device structure. Numerical solutions of quantum Liouville equation were also introduced to investigate transport perpendicular to the conducting channel under the device contacts to provide insight as to how carriers ... |
|
| Quantum Devices and Structures |
26 MAR 91 |
35 pages |
| Authors:
H. L. Grubin; T. R. Govindan; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| All devices constructed from quantum mechanical resonant tunneling structures are dependent upon their ability to move charge in and out of the quantum well. The ability to effectively modulate this charge is dependent upon the device structure; which in turn depends upon an understanding of quantum device physics; which in turn depends upon device theory, simulation, and experiment. In the present study, Scientific Research Associates, Inc. implemented its time-dependent quantum ... |
|
| Transport Via Moments of Quantum Distribution Functions |
10 DEC 90 |
23 pages |
| Authors:
H. L. Grubin; T. R. Govindan; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This study represents the first comprehensive effort to assess through (1) numerical simulations of the equation of motion of the density matrix, and (2) approximate analytical procedures involving an expansion of the Lioville potential, the multiplicative constant associated with the quantum potential as used in quantum hydrodynamic transport. It was found that when quantum effects are 'corrections' to classical calculations, as in N(+)N(-)N(+) structures the factor 1/3' is a satisfactory ... |
|
| Intelligent Manipulation Technique for Multi-Branch Robotic Systems. |
DEC 1990 |
|
| Authors:
A. Y. K. Chen; E. Y. S. Chen; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
 | New analytical development in kinematics planning is reported. The INtelligent KInematics Planner (INKIP) consists of the kinematics spline theory and the adaptive logic annealing process. Also, a novel framework of robot learning mechanism is introduced. The FUzzy LOgic Self Organized Neural Networks (FULOSONN) integrates fuzzy logic in commands, control, searching, and reasoning, the embedded expert system for nominal robotics knowledge implementation, and the self organized neural networks for the dynamic ... |
|
| Numerical Simulation of the Comparative Electrical Performance of the Permeable Base Transistor, Opposed Gate-Source Transistor and Heterostructure Launched Ballistic Field Effect Transistor |
OCT 90 |
111 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; M. Meyyappan; B. J. Morrison; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Devices operate under large signal conditions. Thus large signal simulations are required. This is illustrated for the permeable base transistor, the heterostructure bipolar transistor and the opposed source-gate transistor. There were a number of ground-breaking results during the course of this study. The most significant is that a simulation was developed that coupled the large signal two dimensional device behavior to the large signal properties of an external circuit. The ... |
|
| Studying Quantum Phase-Based Electronic Devices |
15 AUG 90 |
107 pages |
| Authors:
H. L. Grubin; M. Cahay; J. P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| A study was undertaken to examine, theoretically, quantum phase-based electronic device. The study was implemented through examination of moments of the Wigner Distribution Function, time dependent solutions to Schrodingers equation in two dimensions and solutions to the equation of motion of the Density Matrix. Solutions were obtained using numerical methods. A variety of problems were considered including simulation of resonant tunneling structures, electron diffraction through an aperture in a potential ... |
|
| Rotating Flow in Radial Turbomachinery |
MAY 90 |
28 pages |
| Authors:
T. R. Govindan; F. J. De Jong; W. R. Briley; H. McDonald; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The present study addresses the development and implementation of computational procedures for analysis and prediction of flows in centrifugal impellers. Two approaches have been investigated: (a) solution of the Navier- Stokes equations, and (b) solution of an approximate set of viscous primary/ secondary flow equations by an efficient spatial marching algorithm. Solution of the Navier-Stokes equations has been directed towards computing the flow field in a rotating centrifugal impeller passage. ... |
|
| Hypersonic Vehicle Environment Simulation. Phase 1 |
MAY 89 |
41 pages |
| Authors:
F. J. De Jong; J. S. Sabnis; H. McDonald; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The hypersonic, viscous, chemically reacting flow around a vehicle in the upper layers of the atmosphere influences vehicle performance, thermal environment, and sensor visibility. Under the Phase I effort; a unique hybrid Navier-Stokes/Monte Carlo method has been successfully developed for the simulation of said hypersonic flows. This method combines a continuum description of the gas mixture with a statistical (or particle ) description of the species transport and the chemical ... |
|
| Numerical Modeling of Two-Terminal Quantum Well Devices |
17 APR 89 |
78 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; M. M. Cahay; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This report discusses in detail the results of a Phase I investigation of aluminum gallium arsenide/ gallium arsenide resonant tunneling devices (RTD) using the moment representation of the density matrix equation and the concept of a quantum potential. One dimensional numerical simulations of the density matrix equation (i.e., continuity and momentum-balance equations) and the Poisson's equation were performed. Our study constitutes the first attempt to solve numerically the moments of ... |
|
| Reciprocal Interactions of Hairpin-Shaped Vortices and a Boundary Layer |
31 DEC 88 |
|
| Authors:
N. S. Liu; S. J. Shamroth; H. McDonald; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The role of hairpin vortices in cyclic production of wall turbulence has been studied in many laboratory experiments, primarily by using flow visualization. Study of hairpin vortices in a fully turbulent environment is greatly complicated by the presence of jitters and other co-existing structures. A viable approach for obtaining better understanding of the role of hairpin vortices in turbulence dynamics is to study the flow events stimulated by synthetically generated ... |
|
| Propulsor Blade Flows |
DEC 88 |
27 pages |
| Authors:
T. R. Govindan; R. Levy; W. R. Briley; S. J. Shamroth; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The performance characteristics of a hydrodynamic propulsor are determined, to a large extent, by complex three-dimensional viscous flow in the blade rows. The ability to compute the complex flow field for use in the design and analysis of performance of a propulsor would be a valuable tool for improving performance. This research addressed computation of the steady flow field in shrouded propulsor blade rows. A prime consideration in the choice ... |
|
| Computational of Flow Around Maneuvering Submerged Bodies |
OCT 88 |
33 pages |
| Authors:
T. R. Govindan; W. R. Briley; R. Levy; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Generalized primary/secondary flow equations and a spatial-marching solution algorithm have been used to develop a procedure to compute the three- dimensional viscous flow around a submerged body in maneuver. The primary/ secondary flow equations are an approximation to the Navier-Stokes equations for flows in which a primary flow direction can be identified. Important elements of the approximation are a locally specified primary flow direction and a decomposition of the secondary ... |
|
| Studying Quantum Phase-Based Electronic Devices |
01 SEP 88 |
21 pages |
| Authors:
H. L. Grubin; J. P. Kreskovsky; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| This report summarizes work confined to use of the moments of the density matrix, for examining transport in quantum phase based devices. There are two significant features of the approach: (1) the introduction of Bohm's quantum potential, and (2) the use of moment equations which are self- consistently coupled to Poisson's equation. There were a number of significant approximations made during this reporting period that are currently being eliminated: (1) ... |
|
| Analysis of the Submarine Appendage Flow Field |
15 AUG 88 |
21 pages |
| Authors:
Ralph Levy; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The corner vortex originating in the hull-sail intersection region is an important component of the submarine flow field. The vortex may play a major role in overall drag, wake development and propeller performance, and may be a major acoustic source. The flow itself is complex, being three-dimensional, viscous and turbulent. Earlier work computed the flow field around the hull and the sail. The present report focuses on the portion of ... |
|
| Validation of a Forward Marching Procedure to Compute Tip Vortex Generation Process for Ship Propeller Blades |
AUG 88 |
35 pages |
| Authors:
F. J. De Jong; T. R. Govindan; R. Levy; S. J. Shamroth; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The tip vortex flow field has a significant influence on the performance a ship propeller. The ability to compute the tip vortex flow field would be valuable aid in the design of ship propellers, and in the analysis of their performance. The present report demonstrates the feasibility of computing the tip vortex generation process with a forward-marching computation procedure. For the purpose of this study, turbulent flow test cases were ... |
|
| Analysis of the Submarine Appendage Flow Field |
AUG 88 |
98 pages |
| Authors:
Ralph Levy; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Input to PEPSIG (Corner Vortex version) consists of an initial card specifying the type of calculation to perform and a title, plus three namelists. Many of the input parameters follows standard FORTRAN convention, unless stated otherwise. (I.e., those starting with I,J,K,L,M or N are INTEGER, and the remainder are real). Keywords: Submarines appendages flow fields; Computer program user manuals. (edc) |
|
| Flow Dynamics Stimulated by Hairpin-Like Vortices in Initially Laminar Boundary Layers |
31 MAR 88 |
|
| Authors:
N. S. Liu; S. J. Shamroth; H. McDonald; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Time-marching spatial simulations of flow events stimulated by hairpin-like vortices in the near-wall region of initially laminar boundary layers are in progress. The behavior characteristics and the underlying physical mechanisms are being examined by using three distinct but related methods of analysis. The results presented in this report are the kinematic and dynamic states in a plane at a given instant. The spatial distributions of various flow quantities over a ... |
|
| Numerical Simulation of the Function of Scientific Instrumentation for Measuring the Speed of Electron Devices |
30 MAR 88 |
|
| Authors:
M. A. Osman; H. L. Grubin; B. J. Morrison; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The feasibility of using numerical simulation to assess the function of scientific instrumentation for measuring the speed of electron devices has been demonstrated by obtaining (1) the dc characteristics of the VHEMT and PHEMT, (2) transient response of the PHEMT to picosecond voltage pulses superimposed on the gate. The drift and diffusion and Poisson's equations were solved in two dimensions. The HEMT and PHEMT demonstrated transconductance of 94 and 375 ... |
|
| Feasibility of Hot-Block Anemometry |
29 FEB 88 |
|
| Authors:
Brian E. Thompson; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| Measurements of the instantaneous velocity vector are wanted in turbulent flows to determine the three components of mean velocity, the six components of the Reynolds stress tensor, and any higher order components required. It is desirable to obtain these velocity characteristics non- obtrusively, but a combination of the difficulty, complexity, cost and need for optical access and seeding, lead to hot-block anemometry as a complementary approach with different uncertainties and ... |
|
| Studying the Physics and Operation of Multi-Terminal Near-Micron and Sub-Micron Length, Hot Electron Semiconductor Devices |
15 FEB 88 |
|
| Authors:
H. L. Grubin; J. P. Kreskovsky; M. Meyyappan; B. J. Morrison; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| The study encompasses a broad examination of transport in submicron and near-micron semiconductor devices through implementation of the moments of the Boltzmann transport equation and the semiconductor drift and diffusion equation. The study utilized advanced algorithms developed at Scientific Research Associates, and recommends development of a network of user based algorithms for closely combined theoretical/experimental interactions. Keywords: Boltzmann transport, Transients, Overshoot, Gallium arsenides, Silicon. |
|
| An Efficient Patched Grid Navier-Stokes Solution for Multiple Bodies. Phase 1 |
03 FEB 88 |
|
| Authors:
Y. T. Chan; Bernard C. Weinberg; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
|
| A major problem area in current computational fluid dynamics technology concerns flows about complex configurations formed by multiple components in relative motion. Major difficulties encountered in such problems are those associated with the grid. For such applications, the geometric constraints of the component elements often require that patched grids be employed. Herein, a novel and efficient procedure is described to solve the time-dependent, multidimensional Navier-Stokes equations about multiple body configurations. ... |
|
| A Navier-Stokes Study of Cascade Flow Fields Including Inlet Distortion and Rotating Stall |
DEC 87 |
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| Authors:
F. Davoudzadeh; N. S. Liu; S. J. Shamroth; S. J. Thoren; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
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| A two-dimensional, unsteady, Navier-Stokes computer code has been developed and applied to general cascade problems including inlet distortion and rotating stall. The code allows an arbitrary number of passages with periodicity conditions applied below the first and above the last passage, thus allowing flows in the computational domain to differ on a passage-by-passage basis. Calculations were performed for both C-grid and H-grid coordinate systems for single passage steady flows, multiple ... |
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| Simulation of the Response of a Gallium Arsenide JFET to Single Particle Radiation in Two and Three Dimensions |
30 SEP 87 |
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| Authors:
J. P. Kerskovsky; H. L. Grubin; B. J. Morrison; SCIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT
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| The response of a GaAs JFET to single particle radiation is simulated in two and three dimensions through numerical solution of the drift and diffusion, and Poisson's equations. Scaling of the particle track density is introduced in the two-dimensional simulation. The two- and three-dimensional results are compared. Qualitative agreement between the three-dimensional simulation are observed, but quantitative differences in current pulses and charge collected at the devices contacts are present. ... |
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