Experimental investigation into transonic flows over tandem cavities

An experimental study was conducted to analyse the pressure distribution al ong the floor of a cavity, with and without the presence of an upstream tan dem cavity, at a constant freestream Mach number of about 0.911. Measuremen ts were made for single cavities and the results compared with those obtain ed in the presence of an upstream tandem cavity. This comparison was made o ver a wide range of geometries, covering open to closed classes of cavities with both identical and different dimensions for the two cavities. The eff ect of the spacing between the two cavities was also studied. The downstrea m cavity is shown to be significantly affected by the presence of an upstre am cavity, with both the overall net static pressure and its gradient being affected, dependent upon the class of cavity geometry and spacing under co nsideration.