Numerical investigation for curved guide vane in gas turbine

A low aspect ratio and curved turbine guide vane with cooling was investigated by 3-D numerical simulation. Through a comparative analysis of schemes with various bowing laws, the mechanism of controlling secondary flow and reducing losses was explored and discussed. The results show that as a result of a smaller range of radial secondary flow, a positively curved blade can improve aerodynamic performance of the cascade, which has a more effect than that of a negatively curved blade. A blade making use of positive curved design could effectively reduce the loss of the upper end-wall and the maximum amplitude of the loss reduction among different schemes reaches 5%. Positive and negative curved designs have little impact on the flow and loss of the lower endwall. When the positive curved design is put into use, the cooling effect of suction surface of the blade does not change a lot. However, the positive design significantly lowers the cooling performance of pressure side and this leads to a rise of high-temperature area.