TESTING OF NUMERICAL METHODS, CONVECTIVE SCHEMES, ALGORITHMS 
FOR APPROXIMATION OF FLOWS, AND GRID STRUCTURES BY THE EXAMPLE OF 
A SUPERSONIC FLOW IN A STEP-SHAPED CHANNEL WITH THE USE OF THE CFX 
AND FLUENT PACKAGES


S. A. Isaev and D. A. Lysenko

UDC 519.95

An unsteady supersonic flow of a nonviscous gas with a 
Mach number M = 3 in a step-shaped channel has been calculated. The 
accuracy of the forecasts made has been analyzed on the basis of the 
Roe dissipation model and the advective upwind splitting method with 
the use of convective schemes of the second and third orders of accuracy 
and algorithms for approximation of flows. Triangular and polyhedral 
grids have been tested. The mechanism of formation of an artificial 
physical instability on grid structures with a local-gradient adaptation 
has been considered. It is shown that the existence of a singular 
point - a right corner - in the computational region causes 
a large phase change in the evolution of the flow.

Keywords: supersonic flow, shock wave, step-shaped 
channel, ideal gas, calculation, FLUENT and CFX packages. 

St. Petersburg State University of Civil Aviation, 38 Pilotov Str., 
St. Petersburg, 196210, Russia; email: isaev3612@yandex.ru. Translated 
from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 2, pp. 326-330, March-April, 
2009. Original article submitted November 7, 2007; revision submitted July 20, 2008.