Howarth–Dorodnitsyn transformation


In fluid dynamics, Howarth–Dorodnitsyn transformation is a density-weighted coordinate transformation, which reduces compressible flow conservation equations to simpler form. The transformation was first used by Anatoli A. Dorodnitsyn in 1942 and later by Leslie Howarth in 1948. The transformation of coordinate to is given by
where is the density and is the density at infinity. The transformation is extensively used in boundary layer theory and other gas dynamics problems.