INVESTIGATION OF THE FLOW-FIELD DOWNSTREAM OF A TURBINE TRAILING-EDGECOOLED NOZZLE GUIDE VANE

A trailing edge cooled low aspect ratio transonic tur-bine guide vane is investigated in the VKI Compression Tube Cascade Facility at an out let Mach number (M) over bar(2,is) = 1.05 and a coolant pow rate mc/mg = 3 percent. The outlet pow field is surveyed by combined total-direc tional pressure probes and temperature probes. Special emphasis is put on the development of low blockage probes. Additional information is provided by oil flow visualizations and numerical pow visualizations w ith a three-dimensional Navier-Stokes code. The test results describe the strong differences in the axial evolution of the hub and tip endwa ll and secondary flows and demonstrate the self-similarity of the mids pan wake profiles. According to the total pressure and temperature pro files, the wake mixing appears to be very fast in the near-wake but ve ry slow in the far-wake region. The total pressure wake profile appear s to be little affected by the coolant flow ejection.