Numerical Study of the Effect of the Ejection Angle on the Cooling Performance of a High-Pressure Gas Turbine

Abstract

In modern gas turbines, the purge flow plays an important role in improving the performance of the gas turbine, as it is adapted against the problem of the ingestion of hot gases in the inter-disc cavity of the turbine. The performance of this purge flow is necessarily influenced by some geometrical and physical parameters. This paper presents a 3D numerical study on the influence of the ejection angle on the cooling performance in a high pressure transonic gas turbine with the presence of the cavity. Five inclination cavity angles are compared (𝝓 = 30°, 45°,60°,75°and 90°) by using ANSYS Fluent, a steady flow Reynolds average Navier-Stokes equations are solved, and the turbulence model k-ω SST has been chosen based on comparison of the distribution of velocity and heat transfer convective coefficient with experimental results in a previous work. It was seen that that cooling is limited to the suction side because of the non-uniform pressure distribution of the main flow and the high pressure of the stagnation point. The optimal configuration was determined for an ejection angle of 30°.

Keywords

• HP transonic gas turbine
• 3D numerical study
• Purge flow
• Ejection angle
• Cooling performance

References

1. Arts, T., Duboue, J. M., & Rollin, G. (1997). Aero-thermal performance measurements and analysis of a two-dimensional high turning rotor blade. American Society of Mechanical Engineers, 3. Vol. 78705, p. V003T09A013
2. Gräf, L., & Kleiser, L. (2014). Film cooling using antikidney vortex pairs: effect of blowing conditions and yaw angle on cooling and losses. Journal of Turbomachinery, 136(1), 011008.