SIMILARITY, DRAG AND LIFT IN TRANSONIC FLOW WITH GIVEN INTERNAL HEAT ADDITION

We investigate the aerodynamic effects of a given distribution of heat sources on the drag and lift in transonic flow over profiles. The str ength and location of the sources simulate essential features of trans onic flow with coupled non-equilibrium phase transitions. Three differ ent aspects are of interest: the transformation of numerical solutions of the Euler equations using the similarity law of Zierep to prove th e invariant character of the reduced representation (see [Z, 1965]; [Z ierep, 1990]); the addition of heat at different locations over the pr ofile which shows the sensitive reaction of the lift and drag; and com parison with results for flows with coupled homogenous condensation to demonstrate the usefulness and limits of modelling this process by gi ven heat sources. The application of Zierep's similarity law to numeri cal solutions of the Euler equation yields remarkably good agreement i n the invariant static pressure distributions over five different NACA profiles. The lift and drag vary over a wide range. Heat addition nea r stagnation points reduces the drag in non-lifting flows by up to 50% , whereas heat addition around the maximum thickness increases the dra g by about 120%. The supersonic compression on the suction side contro ls the lift decrease in asymmetric flows. The aerodynamic variations a re similar in tendency to those in linear subsonic flow, but superimpo sed upon and quantitatively strengthened by the displacement of the no rmal shock.