Compressible Fluid in Motion

The aerodynamic study of an airplane is performed by considering an initial steady horizontal motion with constant speed (the freestream velocity). Thus, it is necessary to solve the partial differential equations by assuming compressible fluid in motion with constant speed (the unsteadiness is considered to be a small perturbation of this constant speed state). This chapter introduces the elementary solutions of the small perturbation velocity potential equation under the assumption of compressible inviscid fluid in motion.