Prediction of Turbulent Flow and Heat Transfer Within Rotating Ribbed Turning Passage
In order to enhance the performance of gas turbine and maintain the blade material endurance within operating temperature range, cooling channels are made within the blade to extract the heat from materials. However, nowadays hot gas temperature has been substantially higher than allowed material temperature. Therefore, optimizing internal cooling schemes is necessary to get higher thermal efficiency and safe operation during life cycle in modern gas turbines. In this paper, the numerical simulation method is used for getting the internal cooling passage pressure coefficient and temperature distribution. 6 times amplification model which is turbine blade internal cooling channel has been studied. Hydraulic diameter of the channel inlet is 11. 2mm. The ratio of Radius gyration and channel inlet hydraulic diameter is 46. Realizable k-ε turbulence model with enhanced wall function is used. The simulation has been done at Rotation number Ro = 0. 0879 and Ro = 0. 0 with different Reynolds number from Re=5000 to 20000, and discharge ratio of each outlet is 27％49％24％. Compare and analyze the characteristics of flow and heat transfer when rotating and nonrotating. The results show that:l) the flow characteristics of rotating channel are different from characteristics of non-rotating channel due to the rotation-induced secondary flow which is produced by coriolis force, buoyancy force and centrifugal force. The pressure coefficients reduce 13. 5％ under rotating condition. 2) Increase the Rotation number which lead to average Nu number increasing and flow resistance decreasing. However, the heat transfer characteristics of different side are difference. Coriolis force is the most intensive ingredient in heat transfer in rotation passage. The heat transfer on pressure-wall is enhanced by the radial outflow, but reduced on the suction-wall. The heat transfer on suction-wall is enhanced by the radial inflow, but reduced on the pressure-wall. 3) The average Nusselt number increases as increasing Reynolds number. The Nusselt number distribution on rotating ribbed channel surface is similar with non-rotation.
ribbed turning passages inner blade coolings rotation convective heat transfer gas turbine
ZHAO Shu ZHU Hin-ren GUO Tao ZHENG Jie LIANG Wei-ying
School of Power and Energy, Northwestern Polytechnical University, Xian, China
国际会议
4th International Symposium on Jet Propulsion and Power Engineering(第四届喷气推进与动力工程国际会议 ISJPPE2012)
西安
英文
285-292
2012-09-10（万方平台首次上网日期，不代表论文的发表时间）