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A computational fluid dynamics simulation of the hypersonic flight of the Pegasus(TM) vehicle using an artificial viscosity model and a nonlinear filtering methodThe computational fluid dynamics code, PARC3D, is tested to see if its use of non-physical artificial dissipation affects the accuracy of its results. This is accomplished by simulating a shock-laminar boundary layer interaction and several hypersonic flight conditions of the Pegasus(TM) launch vehicle using full artificial dissipation, low artificial dissipation, and the Engquist filter. Before the filter is applied to the PARC3D code, it is validated in one-dimensional and two-dimensional form in a MacCormack scheme against the Riemann and convergent duct problem. For this explicit scheme, the filter shows great improvements in accuracy and computational time as opposed to the nonfiltered solutions. However, for the implicit PARC3D code it is found that the best estimate of the Pegasus experimental heat fluxes and surface pressures is the simulation utilizing low artificial dissipation and no filter. The filter does improve accuracy over the artificially dissipative case but at a computational expense greater than that achieved by the low artificial dissipation case which has no computational time penalty and shows better results. For the shock-boundary layer simulation, the filter does well in terms of accuracy for a strong impingement shock but not as well for weaker shock strengths. Furthermore, for the latter problem the filter reduces the required computational time to convergence by 18.7 percent.
Document ID
19960009469
Acquisition Source
Legacy CDMS
Document Type
Thesis/Dissertation
Authors
Mendoza, John Cadiz (California Univ. Los Angeles, CA, United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1995
Publication Information
Publisher: NASA
Subject Category
Aerodynamics
Report/Patent Number
NASA-CR-186033
H-2071
NAS 1.26:186033
Accession Number
96N16635
Funding Number(s)
PROJECT: RTOP 466-01-00
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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