Panel Methods in Computational Fluid Dynamics

Abstract

in the field of computational fluid dynamics that the more generally the physics of the flow is modeled by a method, the less general is the boundary geometry to which the method is applicable. Part of the difficulty lies in the stringent requirements on the calculational grid in the field of flow. According to the above observation, the simp lest meaningful flow physics- that of invi scid, in compressible potential flow­ should be applicable to the most general geometries. Indeed, as is well known, this problem can be formulated as a linear integral equation over the boundary, thus eliminating the need for a field grid and allowi ng the possibility that a potential-flow method formulated in this way can be capable 'of obtaining flow solutions about completely arbitrary con­ figurations. Happily, this generality substantially can be achieved in prac­ tice, although with more analytical and programming effort than most publications on the subject are prepared to admit. At the same time, the predictions of such methods have been found to agree well with experiment over a surprisingly large range of flow conditions. Even when their results fail to give the proper experi mental values, they are frequently useful in predicting the incremental effect of a proposed design change or in ordering various designs in terms of effectiveness. This perhaps fortuitous agreement with real flow, combined with their geometric generality, has made numeri­ cal potential-flow methods indispensable design tools in many fields. For example, in the author's company a major design calculation (e.g. flow