Measurements of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Turbine Blade Tip Geometries.

摘要

This report results from a contract tasking Imperial College of Science. Technology and Medicine as follows: The project will involve the quantification of the flow and surface characteristics of turbine blade tip cooling geometry with velocity and turbulence distributions relevant to the gas turbine designer. The experimental program will provide measurements of the film cooling adiabatic effectiveness and heat transfer coefficient in a simulated blade tip. with injection from the pressure surface side near the tip. The program will be progressive and interactive. starting with a single row of film cooling holes with injection from the pressure surface side near the tip. moving towards other representative injection configurations: slot injection on the tip surface and groove-tip geometry. The project will supply validation data for the 3D Navier-Stokes solver Glenn-HT. currently used by NASA. and it will also provide insight into the performance of advanced cooling geometry configurations. The experiments will make use of liquid crystal thermography to obtain the heat transfer data. The data acquisition method corresponds to the steady-state technique with the use of wide band liquid crystals. It requires a reduced number of experiments when compared with narrow band crystals and thermocouples, and provides a high degree of spatial resolution and reduced uncertainty level. It will be accompanied by data from small-diameter thermocouples. hot wires and pressure transducers.