Flow and heat transfer characteristics for single and multiple rows of circular jets impinging on a concave surface are investigated experimentally. The dimensions of the concave target plate, impingement tube, orifice diameter, intra jet spacing are so selected that the present system represents a scaled-up (30: I) model for the leading edge of a typical gas turbine nozzle guide vane. The target plate is kept at a distance of one orifice diameter from the impingement tube, whilst the ratio of inter-jet distance to jet diameter is maintained at a value of 5.4. The parameters which are varied in the study include jet Reynolds number (Red=2847-19300) and number of rows (nR=l and 5).The local dimensionless pressure and Nusselt number variations along the concave plate are presented at these parameters. A performance number named Thermo Hydrodynamic Performance Ratio (THPR) is introduced to evaluate different configurations on the basis of a combined pressure drop and heat transfer. Usage of multiple jets appears to oiler much better THPR than that of single jet or single row of jets, for a chosen plenum condition. Copyright © 2008 by ASME.