TY - GEN
T1 - Development of the ellipsoidal statistical bhatnagar-gross-krook method for hypersonic flows
AU - Patil, Varun N.
AU - Tumuklu, Ozgur
AU - Li, Zheng
AU - Levin, Deborah A.
PY - 2014
Y1 - 2014
N2 - To avoid the high computational costs related to the DSMC method for low Knudsen number flows, a new particle method, based on the solution to the ES-BGK model of the Boltzmann equation, is investigated. In this method, a fraction of the particles in a cell is selected for velocity reassignment from the local Maxwellian distribution based the collision frequency and an even smaller fraction is selected for rotational energy reassignment based the rotational relaxation rate. Zero-dimensional simulation results show that the method can model well the rotational relaxation. When simulating the argon flow over a cone with a weak shock, it is found that a minimum of forty selected particles for transitional velocity reassignment are required to achieve energy conservation and then good agreement with flow properties simulated with DSMC. However, same number of simulated particles per cell for the case with nitrogen flow is not sufficient to model the rotational relaxation rate and results show relatively good agreement for transitional temperature but poor agreement for rotational temperature.
AB - To avoid the high computational costs related to the DSMC method for low Knudsen number flows, a new particle method, based on the solution to the ES-BGK model of the Boltzmann equation, is investigated. In this method, a fraction of the particles in a cell is selected for velocity reassignment from the local Maxwellian distribution based the collision frequency and an even smaller fraction is selected for rotational energy reassignment based the rotational relaxation rate. Zero-dimensional simulation results show that the method can model well the rotational relaxation. When simulating the argon flow over a cone with a weak shock, it is found that a minimum of forty selected particles for transitional velocity reassignment are required to achieve energy conservation and then good agreement with flow properties simulated with DSMC. However, same number of simulated particles per cell for the case with nitrogen flow is not sufficient to model the rotational relaxation rate and results show relatively good agreement for transitional temperature but poor agreement for rotational temperature.
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M3 - Conference contribution
AN - SCOPUS:84902780460
SN - 9781624102561
T3 - 52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014
BT - 52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014
PB - American Institute of Aeronautics and Astronautics Inc.
T2 - 52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014
Y2 - 13 January 2014 through 17 January 2014
ER -