BIFURCATION OF A TRANSONIC IDEAL-GAS FLOW AROUND 
A SYMMETRIC AIRFOIL WITH A CONCAVITY

K. V. Babarykin

UDC 533.6.011

A transonic flow around a symmetric airfoil with a concavity 
in its central part has been numerically investigated. The dependences 
of the lift coefficient on the Mach number of the incident flow M and 
on the angle of attack  were determined. It is shown that, depending on 
M, in the flow past the upper part of the indicated airfoil there can arise one 
or two supersonic-flow regions. It has been established that, at fairly 
large angles of attack, the coalescence and separation of supersonic-flow 
regions are realized in a discrete way. For these angles of attack, 
singular Mach numbers Ms, in the neighborhood of which the structure 
of the flow is transformed, were determined and the physical processes occurring 
in this case were analyzed. It was found that the flow being considered is
characterized by a large hysteresis in M.

St. Petersburg State University, 28 Universitetskii Ave., 
St. Petersburg, 198504, Russia; email: konst20@mail.ru. Translated 
from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 4, pp. 63-68, 
July-August, 2007. Original article submitted October 28, 2005.