This paper describes the method for accurately estimating profile loss using measured flow parameters in a low speed cascade test. One of the issues of the control volume analysis for obtaining the mixed-out profile loss is to give realistic flow conditions on the control surface at the trailing edge plane. In this paper, the flow conditions at the trailing edge plane are related to the measured velocity distribution on the suction surface from throat to the trailing edge using the concept of circulation.
The validity of the estimation method is verified by using the results of steady Reynolds Averaged Navier-Stokes (RANS) simulation. In this verification, the verification profile loss of the RANS simulation is obtained by using the calculated drag forces of surface pressure and surface shear stress. The verification is conducted for two kinds of blade profiles at three different Reynolds numbers, 57,000, 100,000 and 147,000, for each blade profile. It is found that all the estimations by the current method are in a range between −10% to +6% of the verification profile losses of the RANS simulations.
This method is applied to the data analysis of low speed cascade tests for the two kinds of blade profiles used in the verification. It is shown that the measured pressure loss downstream of the cascade includes an additional loss to the profile loss even in the steady flow.