Artificial thickening of cavitation tunnel boundary layers

Preliminary measurements of natural and thickened boundary layer mean velocity profiles on the ceiling of a cavitation tunnel test section are presented. The method of thickening tested is via an array of transverse injected jets. The array consisted of 252 equal diameter jets on a triangular grid on 8 spanwise rows. Several Reynolds numbers, jet flow rates and streamwise locations downstream of the thickening location were tested. Natural and thickened mean velocity profiles are compared with the laws of the wall and wake. At the most downstream location tested natural boundary layers with momentum thickness Reynolds numbers of 33000 could be thickened to over 73000 with minor but apparent remnant distortions from the artificial thickening.