Analysis of turbine flow field under low Reynolds number condition

The flow field in turbine was investigated using three-dimensional numerical simulation method. The flow structures in different altitude were compared and analyzed, to show the effect on flow structure and turbine performance with the decrease of Reynolds number. The results indicate that on the condition of high altitude, the Reynolds number is decreased nearly one order, and the blade loading distribution is changed, large separation is found on blade suction surface, and secondary flow and radial mixing effects enhance obviously, so that the performance is changed worse and the efficiency is dropped rapidly. These factors should be paid more attention to the aerodynamic design of turbine under low Reynolds number condition. Moreover the selection of loading distribution form is also an important factor of the design.