No abstract

In this article, the effects of film cooling holes arrangement and groove depth on the heat transfer and film cooling performance of blade tip are investigated. For this numerical research, a high-pressure turbine blade with the squealer tip is applied, and the tip clearance is given to be 0.8 mm (1% of the blade span). Simultaneously, a typical tip cooling technology of film holes in the groove floor is used. The number of film holes is fixed at 10, and two kinds of holes arrangements are considered: (1) equidistance distribution and (2) dense distribution near the leading edge. Three groove depths are studied with the values of 1.5, 2.0, and 2.5 mm (1.875%, 2.5%, and 3.125% of the blade span, respectively). The results show that the area-averaged film cooling effectiveness is higher when the holes distribute densely near the leading edge, and the cooling effect of the groove depth with 2.0 mm is obviously high compared with the other two depths.

Purpose Blade tip clearance has always been a concern for the gas turbine design and control. The numerical analysis of tip clearance is based on the turbine components displacement. The purpose of this paper is to investigate the thermal and mechanical effects on a real cooling blade rather than the simplified model. Design/methodology/approach The coupled fluid-solid method is used. The thermal analysis involves solid and fluid domains. The distributions of blade temperature, stress and displacement have been calculated numerically under real turbine operating conditions. Findings Temperature contour can provide a reference for stress analysis. The results show that temperature gradient is the main source of solid stress and radial displacement. Compared with thermal or mechanical effect, there is a great change of stress magnitude for the thermomechanical effect. Large stress gradients are found between the leading and trailing edge of turbine cooling blade. Also, the blade radial displacement is mainly attributed to the thermal load rather than the centrifugal force. The analysis of the practical three-dimensional model has achieved the more precise results. Originality/value It is significant for clearance design and life prediction.

No abstract

No abstract