Extension of the Blasius force theorem to subsonic speeds
Abstract
The theorem considered by Blasius (1910) represents a wellknown method for calculating the force on a body situated in an incompressible, inviscid twodimensional flow. The efficiency of the Blasius theorem is due to its quality of expressing the forces with the aid of contour integrals of analytic functions of complex variables. The present note has the objective to deduce an analog of Blasius theorem for the aerodynamic forces in subsonic flow. It is assumed that an approximate velocity potential of the subsonic flow has been calculated by using the ImaiLamla method. It is pointed out that this method is a variant specially suited for the twodimensionally flows of the JanzenRayleigh expansion method. The derived formula expresses the aerodynamic forces with the aid of contour integrals of analytic complex functions. It can be regarded as the Blasius theorem with firstorder compressibility correction for the subsonic speed regime.
 Publication:

AIAA Journal
 Pub Date:
 November 1985
 DOI:
 10.2514/3.9170
 Bibcode:
 1985AIAAJ..23.1811B
 Keywords:

 Aerodynamic Forces;
 Blasius Equation;
 Subsonic Flow;
 Approximation;
 Differential Equations;
 Flow Equations;
 Two Dimensional Flow;
 Fluid Mechanics and Heat Transfer