Flow measurements using LDV and flow analysis in the exit region of a radial inflow turbine

Detailed flow investigation in the downstream region of a radial inflow turbine has been performed using a three component Laser Doppler Velocimetry. The flow velocities are measured in the exit region of the turbine at an off-design operating condition. The results are presented as contour and vector plots of mean velocities, flow angles and turbulent stresses. The measured parameters are correlated to the rotor blade rotation to observe any periodic nature of the flow. The measurements reveal a complex flow pattern near the tip region at the rotor exit due to the interaction of the tip clearance flow. The degree of swirl of the flow near the tip region at the rotor exit is observed to be high due to the gross under turning of the flow near the tip region. The swirl of the flow near the pressure surface was found to be higher than that near the suction surface at the measurement plane nearest to the rotor exit. The effect of the rotor on the exit flow field is observed in the proximity of the rotor exit. The separation behind the rotor hub and its influence on the exit flow field are captured in this investigation.;A limited numerical computation of the flow field has also been performed in the meridional plane at the exit of the tested radial turbine. Steady, axisymmetric, compressible, turbulent viscous flow computations were performed using the code, "PARC" with a two equation k-...