
Accession Number : ADA326201
Title : Numerical Simulation of BGKBurnett Equations.
Descriptive Note : Final rept. 1 Feb 9530 Nov 96,
Corporate Author : WICHITA STATE UNIV KS
Personal Author(s) : Agarwal, Ramesh K. ; Balakrishnan, Ramesh
PDF Url : ADA326201
Report Date : 15 AUG 1996
Pagination or Media Count : 73
Abstract : Recently it has been shown using Boltzmann's HTheorem that the conventional Burnett equations violate the second law of thermodynamics, and hence must not be employed for fluid dynamic simulations. To overcome this difficulty, a new set of equations, designated the BGKBurnett equations was derived recently by the authors. A secondorder distribution function was derived by employing the ChapmanEnskog expansion on the BGKBoltzmann equation. Moments of the BGKBoltzmann equation with the collision invariant vector using the secondorder distribution function yield the BGKBurnett equations. It has been shown by the authors that the BGKBurnett equations are stable to small wavelength disturbances and that they yield results consistent with the second law of thermodynamics. In order to prove that these equations are indeed entropy consistent, it is shown that the secondorder distribution function does not violate Boltnmann's HTheorem. This new set of equations must be used for computing hypersonic flows at moderate Knudsen numbers. The BGKBurnett equations are employed to compute the hypersonic shock structure. The results of the computations show that under certain flow conditions, the conventional Burnett equations violate the second law of thermodynamics while the BGKBurnett equations provide entropy consistent results.
Descriptors : *COMPUTATIONAL FLUID DYNAMICS, *HYPERSONIC FLOW, HEAT TRANSFER, COMPUTERIZED SIMULATION, STRESS ANALYSIS, SHOCK WAVES, FINITE DIFFERENCE THEORY, FLOW FIELDS, PARTIAL DIFFERENTIAL EQUATIONS, TWO DIMENSIONAL FLOW, MAXWELLS EQUATIONS, HYPERSONIC CHARACTERISTICS, HEAT FLUX, BOLTZMANN EQUATION, ENTROPY, KNUDSEN NUMBER.
Subject Categories : Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE