Experimental studies of subsonic flow around a tandem of permeable and solid disks

Some results of experimental studies on subsonic flow around a pair of coaxial disks are discussed with consideration of changes in the permeability of the front disk and in the attack angle of the tandem. Various schemes of flow are visualized. The aerodynamic drag is determined. The results are compared with the well-known data obtained by Bohn and Morel (1980). It is found that the front disk permeability has a stabilizing effect in the case when the mixing layer is unstable at the separation region boundary between the disks.