Brard 
WING PROFILE IN A QUASI-RECTILINEAR, NON-UNIFORM 
MOTION 
This problem has been considered by many authors and fi- 
nally solved by von Karman and Sears in 1938 eal . These authors 
gave the correct form of the Volterra integral equation for the total 
circulation [ around the profile. They showed, in particular, how 
the circulation behaves following a perturbation in form ofa step 
function occurring at time t,. The response time is long and appro- 
ximately corresponds to a path equal to 15 times the chord, but the 
effect of the total virtual masses is considerable and the lift at time 
to + 0 is half its final value. In [3] the writer has completed the 
calculation in order to obtain the pressure distribution on the profile. 
UNSTEADY THREE-DIMENSIONAL MOTION OF A WING WITH A 
FINITE ASPECT RATIO 
There now exist methods for solving the previous problem 
in the case of a thin wing of finite aspect ratio when the amplitudes 
of the deviations from a uniform motion of translation are small. 
Dat and Malfois [4 ] have given a linearized theory using an accele- 
ration potential py = We ist with 
09 F ist 
= oe + is" P \ £6 =P : 
¥ Bin Sie ae e 
Vr being here in the negative x-direction. The pressure P is 
given by 
The component in the vertical direction of the velocity is 
Wie wie wie S | K(x -§ y-7) 6p(§,n) dédn, 
4anpVi 
wing 
1254 
