A5103246502- Gas Dynamics and Kinetic Theory
- Combustion and flame dynamics
- Fire dynamics and safety research
- Computational Fluid Dynamics and Aerodynamics
- Combustion and Detonation Processes
- Fluid Dynamics and Turbulent Flows
- Lattice Boltzmann Simulation Studies
- Energetic Materials and Combustion
- Advanced Combustion Engine Technologies
- Microfluidic and Capillary Electrophoresis Applications
- Plasma and Flow Control in Aerodynamics
- Air Traffic Management and Optimization
- Innovative Microfluidic and Catalytic Techniques Innovation
- Radiative Heat Transfer Studies
- Advanced Numerical Methods in Computational Mathematics
- Atmospheric chemistry and aerosols
- Microfluidic and Bio-sensing Technologies
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Traffic control and management
- Catalytic Processes in Materials Science
- Coagulation and Flocculation Studies
- Simulation Techniques and Applications
- Magnetic confinement fusion research
- Particle Dynamics in Fluid Flows
University of Maryland, College Park
1986-2022
United States Naval Research Laboratory
2003-2012
Naval Research Laboratory Laboratories for Computational Physics & Fluid Dynamics
1996-2012
Computational Physics (United States)
1996-2012
United States Navy
1993-2006
Korea Advanced Institute of Science and Technology
1993
A new microfluidic mixer is presented consisting of a rectangular channel with grooves placed in the top and bottom. This not only increases driving force behind lateral flow, but allows for formation advection patterns that cannot be created structures on bottom alone. Chevrons, pointing opposite directions bottom, are used to create pair vortices positioned side by side. Stripes running width generate vertically stacked vortices. Computational fluid dynamics (CFD) simulations model...
On-orbit firings of both liquid and solid rocket motors provide localized disturbances to the plasma in upper atmosphere. Large amounts energy are deposited ionosphere form expanding exhaust vapors which change composition flow velocity. Charge exchange between neutral molecules background ions (mainly O <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ) yields energetic ion beams. The rapidly moving pickup excite instabilities yield...
This paper presents a general approach for developing an automated, fast and flexible procedure to determine the reaction parameters simplified chemical-diffusive model simulate flame acceleration deflagration-to-detonation transition (DDT) in stoichiometric methane–air mixture. The uses combination of genetic algorithm Nelder-Mead optimisation scheme find optimal rate based on Arrhenius form conversion reactants products. finds six that reproduce detonation properties. Results show closely...
A computational "toolbox" for the a priori design of optimized microfluidic components is presented. These consist microchannel under low-Reynolds number, pressure-driven flow, with an arrangement grooves cut into top and bottom to generate tailored cross-channel flow. An advection map each feature (i.e., groove particular shape orientation) predicts lateral transport fluid within channel due that feature. We show applying these maps in sequence generates excellent representation outflow...
The blue whirl is a small, stable, spinning flame that evolved spontaneously in recent laboratory experiments while studying turbulent, sooty fire whirls. It burns range of different liquid hydrocarbon fuels cleanly with no soot production, presenting previously unknown potential way for low-emission combustion. Here, we use numerical simulations to present the and flow structure whirl. These show composed three flames-a diffusion premixed rich lean flames-all which meet fourth structure,...
A dynamic Monte Carlo-type lattice model has been developed to simulate the agglomeration of nonspherical chain-like agglomerate combustion aerosols due Brownian motion. Simulations are carried out in free molecular and continuum regimes, for both initial mono-disperse lognormally distributed aerosols, with without source mechanisms, at number densities ranging from 1 × 109 cm−3 5 10,0 cm−3. Preservation structure is accomplished throughout simulation by describing as fractal, that is,...
A new computational approach to the modeling and design of efficient microfluidic mixers is demonstrated. The created provide far more rapid mixing than previous designs. set mixer components mapped using a traditional Navier–Stokes fluid solver. maps are used quickly model effect each component has on lateral distribution species in channel. For given length, all possible combinations can be evaluated, best for metric found. Although presented this study short (length-to-width ratios below...
Gaseous flows in microfluidic devices are often characterized by relatively high Knudsen numbers. For such flows, the continuum approximation is not valid, and direct simulation Monte Carlo (DSMC) may be used to find an appropriate solution. low-velocity where fluid velocity much smaller than mean molecular velocity, large statistical fluctuations solution that features of flow obscured noise The use a high-order, nonlinear monotone convection algorithm, flux-corrected transport (FCT), as...
A new Barely Implicit Correction (BIC) algorithm is presented for the simulation of low-Mach-number flows. This based on original, introduced by G. Patnaik et al. [G. Patnaik, R. H. Guirguis, J. P. Boris and E. S. Oran, barely implicit correction flux-corrected transport. In: Journal Computational Physics 71.1 (1987), pp. 120], which was a solution procedure including an explicit predictor step to solve convective portion Navier–Stokes equations corrector remove acoustic limit integration...
We introduce a coupled multiscale, multiphysics method (CM 3 ) for solving the behaviour of rarefied gas flows. The approach is to solve kinetic equation gases (the Boltzmann equation) over very short interval time in order obtain accurate estimates components stress tensor and heat-flux vector. These are used close conservation laws mass, momentum energy, which subsequently advance continuum-level flow variables forward time. After finite interval, solved again new continuum field, cycle...
Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.
The effects of two-dimensional gas radiation on the flame behavior over a solid fuel plate are explored. theoretical model includes elliptic type momentum, energy and species equations with second-order single-step chemical reaction Arrhenius type. discrete ordinates method is employed to solve radiative transfer equation. Numerical calculations performed for wide range mass absorption coefficients wall emissivities characterize behavior. When stronger, heat loss causes retreat downstream,...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCondition numbers as criteria for evaluation of atmospheric aerosol measurement techniquesFariba F. Farzanah, Carolyn R. Kaplan, Po Y. Yu, Juan. Hong, and James W. GentryCite this: Environ. Sci. Technol. 1985, 19, 2, 121–126Publication Date (Print):February 1, 1985Publication History Published online1 May 2002Published inissue 1 February 1985https://pubs.acs.org/doi/10.1021/es00132a001https://doi.org/10.1021/es00132a001research-articleACS...
A series of direct simulation Monte Carlo calculations flows through microfilters were performed to evaluate the range validity a previously derived scaling law. This law, which describes how pressure drop across filter depends on Reynolds number and geometry, is based Navier-Stokes experiments in continuum regime. The simulations show that this law predicts correct dependence for fixed Knudsen number, but magnitude overpredicted as effects due collisional nonequilibrium become important....