LI Guangchao, DOU Xiangyu, ZHANG Wei, et al. Effect of wall-to-gas temperature ratio on heat transfer characteristics of transonic gas turbine blades[J]. Thermal power generation, 2018, 47(8): 44-49.
LI Guangchao, DOU Xiangyu, ZHANG Wei, et al. Effect of wall-to-gas temperature ratio on heat transfer characteristics of transonic gas turbine blades[J]. Thermal power generation, 2018, 47(8): 44-49. DOI: 10.19666/j.rlfd.201710115.
Experiments on temperature ratio of the actual wall surface to gas of the gas turbine blades have the problems of high cost and large measurement error. Using numerical simulation can avoid the difficulties caused by high-temperature experiments. In this study
the Nusselt number and velocity distribution on the suction and pressure surfaces of the blades are studied by numerical simulation using the Fluent commercial software when the inlet and outlet pressure ratio of the cascade is 2 and the wall-to-gas temperature ratio(T_R) is 0.7
0.8 and 0.9
respectively. The results show that the larger the temperature ratio T_R is
the smaller the dimensionless temperature gradient near the wall and the Nusselt number on the blade surface are. The maximum difference of the Nusselt number is up to 32% between the temperature ratio T_R of 0.7 and 0.9. With the increase of the temperature ratio T_R
the position of the separation bubble on the suction surface is closer to the leading edge and the range of the separation bubble along the flow direction and the normal direction is increased. The Nusselt number of the blade surface rises sharply in the main direction in the range from x/d=0.836 to x/d=0.884
due to the separation and reattachment of the turbulent boundary layer caused by the separation bubble. The results in this study can provide a theoretical basis for the design modification of actual wall-to-gas temperature ratio of the gas turbine.