Variable soft sphere molecular model for air species

Abstract

A reliable set of cross-section parameters of the variable soft sphere (VSS) molecular model is determined for the Monte Carlo simulation of air species from the transport collision integrals or potential parameters provided by Cubley and Mason [Phys. Fluids 18, 1109 (1975)] over the high-temperature range 300–15 000 K. The VSS cross-section parameters for the inverse-power-law potential are also determined from the viscosity coefficients recommended by Maitland and Smith [J. Chem. Eng. Data 17, 150 (1972)] for common species in the low (20–300 K) and high (300–2000 K) temperature ranges.

Rovibrational Energy Transitions and Coupled Chemical Reaction Modeling of H+H2and He+H2in DSMC

“…By multiplying r ith the measured value. In He+H 2 , the rotational relaxation occurs faster than (15) where τ r and τ v are rotational and vibrational relaxation times, respectively. In the present work, the relaxation times of the state-resolved method are determined by the e-folding curve-fit method proposed by Kim et al [7,8].…”

“…Previously, variable hard-sphere (VHS) [1], variable soft-sphere (VSS) [14,15], general hard-sphere (GHS) [16], and general soft-sphere (GSS) [17,18] models were developed to determine the total cross sections in the DSMC calculations. However, these previous models have limitations to be employed in the state-resolved method.…”

Temperature Effect on a HDD Slider’s Flying Performance at Steady State

“…However, some macroscopic quantities calculated via the HS model, such as viscosity, can at most qualitatively agree with experimental results. The VSS model [14,15] …”

CFD validation of shock-shock interaction flow fields

“…MONACO employs the Variable Soft Sphere (VSS) collision model of Koura et al [15], a variable rotational energy exchange probability model of Boyd [16] and the variable vibrational energy exchange probability model of Vijayakumar et al [17]. The flow conditions here do not involve chemical reactions.…”