*Max A. Heaslet, Harvard Lomax, John R. Spreiter*

*naca-tn-1824*

*Jan 1950*

The partial differential equation for the perturbation velocity potential is examined for free-stream Mach numbers close to and equal to one. It is found that, under the assumptions of linearized theory, solutions can be found consistent with the theory for lifting-surface problems both in stationary three-dimensional flow and in unsteady two-dimensional flow. Several examples are solved including a three-dimensional swept-back wing and a two-dimensional harmonically oscillating wing, both for a free-stream Mach number equal to one.

*An Adobe Acrobat (PDF) file of the entire report:*

http://naca.central.cranfield.ac.uk/reports/1949/naca-tn-1824.pdf