Numerical analysis and design optimization on full coverage film-cooling for turbine guided vane

Abstract

Based on numerical simulations, the heat transfer and flow field of a turbine vane are analyzed and the film cooling is improved. The optimization objective is increasing the overall cooling effectiveness with cascade pressure loss factors staying almost unchanged. Thus, cylindrical film holes were replaced by laidback holes and V-crater holes. To analyze the effect of structural adjustment on the vane, pressure distributions, mass flow distributions, and heat transfer coefficients were investigated for internal and external cooling systems. To explain the advantages of shaped holes over cylindrical holes, the flow mechanisms, film superposition, discharge coefficients, blow ratios, and film cooling effectiveness were compared. Meanwhile, the influence of mass flow ratios and mainstream Reynolds numbers was analyzed. After optimization, at the design condition, the overall cooling effectiveness increased by 4.19% on the pressure surface and 1.78% on the suction surface. However, the cascade pressure loss factor increased by 0.26% only.

Keywords

• Conjugate heat transfer
• turbine vane
• film cooling
• V-crater hole
• laidback hole
• discharge coefficient