Particle Simulation of Detonation in Microchannel

2009 ◽  
Author(s):  
Yevgeniy A. Bondar ◽  
Mikhail S. Ivanov
Keyword(s):  
Detonation Wave ◽  
Chemical Kinetics ◽  
Numerical Study ◽  
Direct Simulation Monte Carlo ◽  
Wave Structure ◽  
Particle Simulation ◽  
Dsmc Method ◽  
Detailed Chemical Kinetics ◽  
Von Neumann ◽  
Dsmc Simulation

Direct simulation Monte Carlo (DSMC) method was applied to numerical study of detonation in an H2/O2 mixture with detailed chemical kinetics on the basis of effective DSMC molecular chemistry models. The process of homogeneous adiabatic autoignition of a stoichiometric H2/O2 mixture diluted by argon was simulated by the DSMC method. The modeling results provide a qualitatively correct description of autoingition process and are in good agreement with the numerical solution of equations of chemical kinetics. The results of the DSMC modeling of an unsteady detonation wave yield the velocity of detonation, which coincides with the Chapman-Jouguet velocity. The internal structure of the detonation wave obtained in the DSMC simulation is in good qualitative agreement with the detonation-wave structure calculated on the basis of the Zeldovich – von Neumann – Doering (ZND) theory.

PARALLEL SOLVER FOR THE SIMULATIONS OF DETONATION WAVES ON UNSTRUCTURED GRIDS

2020 ◽  
Author(s):  
A. I. Lopato ◽  
◽  
A. G. Eremenko ◽  
Keyword(s):  
Chemical Kinetics ◽  
Numerical Scheme ◽  
Unstructured Grids ◽  
Numerical Study ◽  
Numerical Approach ◽  
Detonation Waves ◽  
Detailed Chemical Kinetics ◽  
Parallel Solver ◽  
Further Development ◽  
Detailed Chemical

Recently, we developed a numerical approach for the simulation of detonation waves on fully unstructured grids and applied it to the numerical study of the mechanisms of detonation initiation in multifocusing systems. Current work is devoted to further development of our numerical approach, namely, parallelization of the numerical scheme and introduction of more comprehensive detailed chemical kinetics scheme.

DSMC Simulation of Low Knudsen Micro/Nanoflows Using Small Number of Particles per Cells

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Ali Amiri-Jaghargh ◽  
Ehsan Roohi ◽  
Hamid Niazmand ◽  
Stefan Stefanov
Keyword(s):  
Direct Simulation Monte Carlo ◽  
Velocity Slip ◽  
Heat Fluxes ◽  
Dsmc Method ◽  
Suitable Alternative ◽  
Low Speed ◽  
Rarefied Flows ◽  
Dsmc Simulation ◽  
Grid Scheme ◽  
Number Of Particles

Direct simulation Monte Carlo (DSMC) method in low Knudsen rarefied flows at micro/nanoscales remains a big challenge for researchers due to large computational requirements. In this article, the application of the simplified Bernoulli-trials (SBT)/dual grid collision scheme is extended for solving low Knudsen/low speed and low Knudsen/high gradient rarefied micro/nanoflows. The main advantage of the SBT algorithm is to provide accurate calculations using much smaller number of particles per cell, i.e., 〈N〉 ≈ 2, which is quite beneficial for near continuum DSMC simulations where the requirement of fine meshes faces the simulation with serious memory restrictions. Comparing the results of the SBT/dual grid scheme with the no time counter (NTC) scheme and majorant frequency scheme (MFS), it is shown that the SBT/dual grid scheme could successfully predict the thermal pattern and hydrodynamics field as well as surface parameters such as velocity slip, temperature jump and wall heat fluxes. Therefore, we present SBT/dual grid algorithm as a suitable alternative of the standard collision schemes in the DSMC method for typical micro/nanoflows solution. Nonlinear flux-corrected transport (FCT) algorithm is also employed as a filter to extract the smooth solution from the noisy DSMC calculation for low speed/low Knudsen number DSMC calculations.

Numerical Study of the Detonation Wave Structure in a Linear Model Detonation Engine

2018 ◽  
Author(s):  
Supraj Prakash ◽  
Romain Fiévet ◽  
Venkatramanan Raman ◽  
Jason R. Burr ◽  
Kenneth H. Yu
Keyword(s):  
Detonation Wave ◽  
Linear Model ◽  
Numerical Study ◽  
Wave Structure ◽  
Detonation Engine

scholarly journals A Zel’dovich–von Neumann–Döring-like detonation wave in a multi-temperature mixture

2019 ◽  
Vol 869 ◽  
pp. 674-705 ◽  
Author(s):  
Damir Madjarević ◽  
Srboljub Simić ◽  
Ana Jacinta Soares
Keyword(s):  
Detonation Wave ◽  
Chemical Reaction ◽  
Wave Structure ◽  
Jump Discontinuity ◽  
Theory Approach ◽  
Reaction Heat ◽  
Von Neumann ◽  
Detonation Structure ◽  
Reversible Chemical Reaction ◽  
Non Equilibrium

The detonation wave structure is analysed in a binary mixture undergoing a reversible chemical reaction represented by $A_{r}\rightleftharpoons A_{p}$. It is assumed that the flow satisfies the proper basic assumptions of the Zel’dovich–von Neumann–Döring (ZND) detonation model, namely the flow is one-dimensional and the shock is represented by a jump discontinuity, but the assumption of local thermodynamic equilibrium is disregarded. This allows us to deeply investigate the coupling between the detonation structure of overdriven detonations and its chemical kinetics. The thermodynamic non-equilibrium effects are taken into account in the mathematical description, using the model of a multi-temperature mixture developed within extended thermodynamics, which has been proved to be consistent with a kinetic theory approach. The reaction rate is then enriched with terms that take into account the temperatures of the constituents. The results show that the temperature difference between components within the detonation wave structure, which describes thermodynamic non-equilibrium, is driven by the chemical reaction. Numerical computations confirm the existence of non-monotonic profiles in the reaction zone of overdriven detonations which are sensitive to changes in the activation energy and reaction heat.

Modeling of Emissions in a Laboratory Swirl Combustor

2015 ◽  
Author(s):  
Viswanath R. Katta ◽  
William M. Roquemore
Keyword(s):  
Chemical Kinetics ◽  
Numerical Study ◽  
Flame Structure ◽  
Detailed Chemical Kinetics ◽  
Swirl Combustor ◽  
Detailed Chemistry ◽  
Hydrocarbon Emission ◽  
Recirculation Zones ◽  
Fuel Mixtures ◽  
Detailed Chemical

A swirl-stabilized combustor utilizes recirculation zones for stabilizing the flame. The performance of such combustors could depend on the fuel used as the cracked fuel products may enter the recirculation-zones and alter their characteristics. A numerical study is conducted for understanding the effects of fuel variation on the combustion and unburned-hydrocarbon-emission characteristics of a laboratory swirl combustor. A time-dependent, detailed-chemistry CFD model UNICORN is used. Six binary fuel mixtures formulated with n-dodecane and n-heptane, m-xylene, iso-octane or hexadecane are considered. A semi-detailed chemical-kinetics model (CRECK-0810) involving 206 species and 5652 reactions for the combustion of these fuels is incorporated into UNICORN code. Calculations are performed for a fuel-lean condition, which represents cruise operation of an aircraft. Combustor flows simulated with different fuel mixtures yielded nearly the same flowfields and flame structures. Production of the intermediate cracked fuel species that are key for the final flame structure and emissions seems to be independent of the fuel used. This finding could greatly simplify the detailed chemical kinetics used for obtaining cracked products. As the cracked fuel species are completely consumed with in the flame zone, no emissions are observed at the combustor exit for the considered fuel-lean condition.

Various Boundary Condition Implementation to Study Microfilters Using DSMC Simulation

2010 ◽  
Author(s):  
Masoud Darbandi ◽  
Hassan Akhlaghi ◽  
Abolfazl Karchani ◽  
Soheyl Vakili
Keyword(s):  
Boundary Condition ◽  
Monte Carlo ◽  
Gas Flow ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Dsmc Method ◽  
Uniform Distributions ◽  
Dsmc Simulation ◽  
Flow Through ◽  
Simulation Monte Carlo

In this study, we present a vast boundary condition treatment to simulate gas flow through microfilters using direct simulation Monte Carlo (DSMC) method. We examine the effects of different boundary condition treatments on the density, pressure, and velocity distributions and suggest the best conditions to simulate gas flow through microfilters. We also refine the effects of upstream and downstream locations on the solution. The results show that uniform distributions can be achieved if we apply the inlet/outlet boundary condition at appropriate upstream and downstream distances. We also show that all the suggested boundary conditions suitably predict the pressure drop coefficient factor across the filter. To evaluate the current results they are compared with some available empirical formulations.

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