Heat transfer measurements of a transonic nozzle guide vane

The heat transfer and aerodynamic characteristics of a turbine nozzle guide vane with a supersonic exit velocity have been measured in a transient cascade facility. The vane possesses a convergent-divergent passage, and this, together with a low trailing edge wedge angle, is seen to control the supersonic flow efficiently at design conditions. Heat transfer measurements have been taken on both suction and pressure surfaces. On the suction surface, transition is marked by a rapid increase in heat transfer, whereas on the pressure surface a slow increase in heat transfer indicates the gradual onset of turbulence. The measurements also indicate possible relaminarisation of the suction surface boundary layer at the impingement of the trailing edge shock. Predictions are presented of aerodynamic flow, using an inviscid time-marching calculation, and heat transfer, using a differential method applied to the vane surface.