Hypersonic, stratified gas flows past an obstacle: Direct simulation Monte Carlo calculations

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · J. Comput. Phys.; (United States)

DOI:https://doi.org/10.1016/0021-9991(88)90170-2· OSTI ID:6907573

Roberts, Jr, W W; Hausman, M A

Computational studies of the three-dimensional hypersonic flow of rarefied, strongly stratified gas past an obstacle are carried out, the incident gas stratified in a direction transverse to the mean flow. An ''N-body'' computational code based on Monte Carlo techniques is developed for these purposes. Our primary interest is centered on the three-dimensional effects induced in the gas flow by a solid obstacle comparable in size to the gas height and collisional mean free path. Of the different types and shapes of obstacles studied, we focus herein on a cylindrical obstacle, assumed to be a diffuse elastic scatterer. The cylindrical obstacle is a short uniform pipe whose upstream end is fully open, facing directly into the flow, and whose downstream end is covered by a flat circular endplate containing an ''orifice'' at its center. For different choices of ''orifice'' diameter, the obstacle serves as a useful model of an impact probe (closed orifice) or scoop (closed, partially open, or fully open orifice) in a rapidly rotating strongly stratified gas (as in a gas centrifuge). The computed results show that the obstacle (in all cases studied, spanning the range from completely closed orifice to fully open orifice) induces large systematic motions in the gas, with strong radially inward driven flow in the direction of the gradient of density stratification, and correspondingly large density perturbations in these regions.

• Research Organization: Department of Applied Mathematics, University of Virginia, Charlottesville, Virginia 22903
• OSTI ID: 6907573
• Journal Information: J. Comput. Phys.; (United States), Journal Name: J. Comput. Phys.; (United States) Vol. 77:2; ISSN JCTPA
• Country of Publication: United States
• Language: English

Related Subjects

640410* -- Fluid Physics-- General Fluid Dynamics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTER CALCULATIONS
COMPUTERIZED SIMULATION
FLOW MODELS
FLUID FLOW
GAS FLOW
HYPERSONIC FLOW
MATHEMATICAL MODELS
MONTE CARLO METHOD
SHOCK WAVES
SIMULATION