INFLUENCE OF LIFT REDISTRIBUTION ALONG
THE LENGTH OF A SUPERSONIC AIRPLANE
ON THE ACOUSTIC-SHOCK PARAMETERS

V. M. Fomin, V. F. Volkov,
and V. F. Chirkashenko

UDC 518.4:533.4:629.7

Results of numerical investigations of the influence of 
lift redistribution along the length of the airframe of an airplane 
arrangement on the parameters of the acoustic shock produced by this 
arrangement and its aerodynamic characteristics are presented. The 
airplane arrangements investigated were constructed by disposition 
of wings in tandem at definite values of the aerodynamic lift and 
the lifting-surface area. The gasdynamic parameters of the flow near 
an arrangement were calculated by the numerical scheme based on the 
integral Euler equations, and the disturbed-pressure distribution 
at a large distance from the arrangement was determined using the 
quasi-linear theory. It is shown that the acoustic-shock level is 
substantially decreased in the case where there arises a middle-zone 
effect and an excess-pressure profile with an N-like shape. The arrangement 
of a supersonic airplane of weight 40 t making a cruise at a height 
H = 18 km and a Mach number M = 2.0, which makes 
it possible to decrease the acoustic shock produced by this airplane 
with no decrease in its lift-drag ratio, was determined.

Institute of Theoretical and Applied Mechanics, Siberian 
Branch of the Russian Academy of Sciences, 4/1 Institutskaya Str., 
Novosibirsk, 630090, Russia; email: lkov@itam.nsc.ru. Translated 
from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 5, pp. 28-37, 
September-October, 2007. Original article submitted April 24, 
2006.