Wind Tunnel Testing and Modeling Implications of an Advanced Turbine Cascade

TL;DR

This study conducts wind tunnel testing on an advanced turbine blade to evaluate aerodynamic performance, compare experimental results with CFD predictions, and analyze the effects of various geometrical and flow conditions.

Contribution

It provides comprehensive experimental data on turbine blade aerodynamics and assesses the predictive accuracy of CFD tools under different flow regimes and geometrical parameters.

Findings

Design successfully achieved target aerodynamic performance.

CFD predictions showed good agreement with experimental data.

Discrepancies identified between measurements and simulations at certain conditions.

Abstract

This paper describes the extensive Wind Tunnel (WT) linear cascade testing campaign carried out on a constant section turbine blade developed for low subsonic applications. Comprehensive experimental program was designed to determine the aerodynamic behaviour of this blade under a wide range of varying geometrical like Pitch to Chord Ratio, Stagger Angle and Aerodynamic like Reynolds Roughness, Mach number, Incidence angle conditions. In addition to the classical Two-Dimensional (2D) measurements, targeted Three-Dimensional (3D) surveys have been performed to complement the 2D results, allowing to draw supplementary conclusions as to the behaviour of the considered blade in three-dimensions. The performed experiments predominantly covered the transitional and beginning of a fully turbulent flow regime (maximum Re is 2.5 million). Post processing of experimental results were done in view of exploitation and judgment of some key aerodynamic aspects; parameters such as profile section load distribution, loss coefficient and flow deviation angle. Alongside with confirmation of the design targets, a parallel goal pursued in the current WT testing, was to get a more accurate idea as to the predictive capabilities of the employed CFD tools (CFX and MISES) under the basic flow condition generated in the WT. The aim was to get a global picture, as to the level of agreement that can be reached by the used design tools while accounting for the afore-mentioned design, operational variables. The obtained measurement results clearly indicated the success of the design in achieving the pre-set targets. The paper further provides a detailed discussion on the identified discrepancies, measurement versus predictions, of the key parameters at the geometric, aerodynamic design as well as off-design conditions.