PRANDTL-GLAUERT TRANSFORMATION
LAMBERT M. SURHONE, MIRIAM T. TIMPLEDON, SUSAN F. MARSEKEN
High Quality Content by WIKIPEDIA articles!
The Prandtl-Glauert transformation or Prandtl-Glauert rule (also Prandtl-Glauert-Ackeret rule) is an approximation function which allows to compare aerodynamical processes occurring at different Mach numbers.
In subsonic flow the compressibility of the fluid (often air) becomes more and more influential with increasing velocity.
Thus, characteristic values of the flow, as found from incompressible, inviscid potential flow theory, can be multiplied with a correction factor to account for the influence of compressibility.
The Prandtl-Glauert transformation is one such correction factor.
The Prandtl-Glauert transformation is found by linearizing the potential equations associated with compressible, inviscid flow.
It was discovered that the linearized pressures in such a flow were equal to those found from incompressible flow theory multiplied by a correction factor.
