Analysis of Averaging Methods for Nonuniform Total Pressure Fields

Abstract A common objective in the analysis of turbomachinery components (nozzle guide vanes (NGVs) or rotor blades, for example) is to calculate performance parameters, such as total pressure kinetic energy (KE) loss coefficients, from measurements a nonuniform flow-field. These parameters can be represented range ways. For example, line-averages used compare between different radial sections 3D component; plane-averages assess flow (perhaps coefficient) development axial planes; and fully mixed-out values determine associated with component. In literature, weighting method line- plane-averaging (e.g., area, volume flow, mass entropy-flux) sometimes regarded an unimportant issue. Indeed, many authors neglect even state which was their work. certain low-speed test cases, where are made long distance component, nonuniformity will relatively small practical difference methods may negligible. However, high-speed applications close component trailing edge, this becomes increasingly unlikely. paper, we calculating aerodynamic parameters—for coefficient—including plane-average schemes several methods. We analyze sensitivities location measurement plane, averaging range, exit Mach number. use high-fidelity experimental data taken planes downstream cascade engine parts: high-pressure (HP) turbine NGVs operating at transonic The complemented by computational fluid dynamics (CFD). discuss underlying physical mechanisms give rise observed sensitivities. provide guidance on accuracy each relevant, application.