Experimental and numerical investigations of aerodynamic behavior of a three-stage high-pressure turbine at different operation conditions

Abstract

Using the Reynolds-averaged Navier–Stokes-based numerical methods to simulate the flow field, efficiency and performance of high-pressure turbine components of multi-stage steam turbines result in substantial differences between the experimental and the numerical results pertaining to the individual flow quantities. These differences are integrally noticeable in terms of major discrepancies in aerodynamic losses, efficiency, and performance of the turbine. As a consequence, engine manufacturers are compelled to frequently calibrate their simulation package by performing a series of experiments before issuing efficiency and performance guaranty. The aim of this article is to investigate the cause of the aforementioned differences by utilizing a three-stage high-pressure research turbine with three-dimensional compound lean blades as the platform for experimental and numerical investigations. Experimental data were obtained using interstage aerodynamic measurements at three measurement stations, namely, downstream of the first rotor row, the second stator row, and the second rotor row. Detailed measurements were conducted using custom-designed five-hole probes traversed in both circumferential and radial directions. Aerodynamic measurements were carried out within a rotational speed range of 1800–2800 r/min. Numerical simulations were performed utilizing a commercially available computational fluid dynamics code. A detailed mesh of the three stages was created and used to simulate the corresponding operating conditions. The experimental and numerical results were compared following a critical discussion relative to differences mentioned above.