Constructal design for gas-turbine blade based on minimization of maximum thermal resistance

A gas-turbine blade cooling model is investigated based on numerical method. Constructal design of the elemental gas-turbine blade (EGTB) is implemented, and its optimal internal and external shapes are obtained. It shows that the maximum thermal resistance (MTR) can be minimized by optimizing the ratios of the cavity diameter to the thickness as well as the thickness to the length of the EGTB. The optimal constructs of the EGTB based on numerical method in this paper and available analytical method are different. The MTR can be further decreased by increasing the cavity fraction and decreasing the ratio of the cavity edge distance to the thickness. Compared the optimal construct of the EGTB obtained by multi-scale constructal optimization with that obtained by single-scale constructal optimization, the MTR of the EGTB is reduced by 51.33%. Therefore, the performance of the EGTB is evidently improved by adopting multi-scale cooling cavities.