A method to calculate the entropy production rate based on the measured velocity flow fields was established based on the similar processes between stereoscopic particle image velocimetry(SPIV)measurement and large eddy simulation(LES).Comparing the turbulence dissipation rate estimated by several typical subgrid-scale(SGS) stress models

it can be found that the result calculated by the mixing model is most reasonable;however

the coefficients CSm and CAm should be well determined.Using the mixing model the entropy production rate of the complex flow fields near the rotor tip region measured by SPIV were analyzed.The results show that at the design condition the losses are mainly caused by the tip leakage vortex

while at the near-stall condition both the tip leakage vortex and the corner vortex can bring large flow losses.