Incorporating vibrational excitation in a hybrid particle-continuum method

A modular particle-continuum (MPC) method is extended to model vibrational excitation to simulate hypersonic steady-state ows that exhibit regions of collisional nonequilibrium in a mainly continuum ow eld. This method loosely couples a DSMC code to an implicit Navier-Stokes solver. By limiting our study to steady-state ows, both time-step and cell size are decoupled between methods. Control of statistical scatter and information transfer between modules is described. Hypersonic ow over a 2-D cylinder is simulated with di erent physical models. Results from DSMC, CFD, and the MPC method are presented and compared. The agreement in vibrational temperature between DSMC and the MPC method decreases as the size of the continuum domain increases, which may be due to the di erence in macroscopic relaxation rates computed in DSMC and CFD. Other ow variables and surface properties remain in excellent agreement between DSMC and the MPC method. The MPC simulation results are obtained using less than half the computational time compared to full DSMC while also decreasing the memory requirements.

[1]  Stefan Dietrich,et al.  Scalar and Parallel Optimized Implementation of the Direct Simulation Monte Carlo Method , 1996 .

[2]  Roger C. Millikan,et al.  Systematics of Vibrational Relaxation , 1963 .

[3]  Thomas E. Schwartzentruber,et al.  A hybrid particle-continuum method applied to shock waves , 2006, J. Comput. Phys..

[4]  Paul W. Terry,et al.  Erratum: ‘‘The observation of isolated long‐lived current filaments in two‐dimensional microtearing turbulence’’ [Phys. Fluids B 3, 304 (1991)] , 1991 .

[5]  Iain D. Boyd.  Analysis of vibrational‐translational energy transfer using the direct simulation Monte Carlo method , 1991 .

[6]  H. S. Wijesinghe,et al.  Discussion of Hybrid Atomistic-Continuum Methods for Multiscale Hydrodynamics , 2004 .

[7]  Leonardo C. Scalabrin,et al.  Hypersonic Aerothermodynamics Analysis Across Nonequilibrium Regimes Using Continuum and Particle Methods , 2007 .

[8]  Leonardo C. Scalabrin,et al.  Development of an Unstructured Navier-Stokes Solver for Hypersonic Nonequilibrium Aerothermodynamics , 2005 .

[9]  Claus Borgnakke,et al.  STATISTICAL COLLISION MODEL FOR SIMULATING POLYATOMIC GAS WITH RESTRICTED ENERGY EXCHANGE. , 1974 .

[10]  Graham V. Candler,et al.  Predicting failure of the continuum fluid equations in transitional hypersonic flows , 1994 .

[11]  R. A. East,et al.  Nonequilibrium Hypersonic Aerothermodynamics. By C. PARK. Wiley, 1990. 358 pp. £47.50 , 1991, Journal of Fluid Mechanics.

[12]  Thomas E. Schwartzentruber,et al.  Hybrid Particle-Continuum Simulations of Nonequilibrium Hypersonic Blunt-Body Flowfields , 2006 .

[13]  Thomas E. Schwartzentruber,et al.  Modular Implementation of a Hybrid DSMC-NS Algorithm for Hypersonic Non-Equilibrium Flows , 2007 .

[14]  Thomas E. Schwartzentruber,et al.  A modular particle-continuum numerical method for hypersonic non-equilibrium gas flows , 2007, J. Comput. Phys..

[15]  Bernie D. Shizgal,et al.  Direct Simulation Monte Carlo Method for Internal-Translational Energy Exchange in Nonequilibrium Flow , 1994 .

[16]  Iain D. Boyd,et al.  Vibrational–translational energy exchange models for the direct simulation Monte Carlo method , 1999 .

[17]  Quanhua Sun,et al.  Evaluation of Macroscopic Properties in the Direct Simulation Monte Carlo Method , 2005 .

[18]  Thomas J. Horvath,et al.  Comparison of a 3-D CFD-DSMC Solution Methodology With a Wind Tunnel Experiment , 2003 .

[19]  Iain D. Boyd,et al.  Numerical investigation of the effects of continuum breakdown on hypersonic vehicle surface properties , 2008 .

[20]  Iain D. Boyd,et al.  Analysis of rotational nonequilibrium in standing shock waves of nitrogen , 1990 .

[21]  Richard G. Wilmoth,et al.  Zonally decoupled direct simulation Monte Carlo solutions of hypersonic blunt-body wake flows , 1994 .

[22]  Iain D. Boyd,et al.  Predicting continuum breakdown in hypersonic viscous flows , 2003 .

[23]  E Glass Christopher,et al.  A 3-D Coupled CFD-DSMC Solution Method With Application to the Mars Sample Return Orbiter , 2000 .

[24]  W. Steckelmacher.  Molecular gas dynamics and the direct simulation of gas flows , 1996 .