Influence of different rim widths on leakage flow

Three-dimensional simulations of squealer tip on GE-E3 blade with eight film cooling holes were numerically studied. The effect of the rim width and the blowing ratio on the blade tip flow was revealed. Numerical simulations were performed to predict the leakage flow and the tip heat transfer with the κ-ε model. For the squealer tip, the depth of the cavity is the same and the width of the shoulder varies to form a narrow rim and a wide cavity, which can decrease the coolant momentum and the tip leakage flow velocity. This cavity contributes to the improvement of the cooling effect in the tip zone. To investigate the leakage flow influenced by the rim width, numerical simulations were made at four different models which have different rim widths of 0.58%, 0.89%, 1.16% and 1.74% axial chord (0.5mm, 0.77mm, 1 mm and 1.5mm, respectively) on both the pressure side rim and the suction side rim. From the simulated results, mathematical equations of mass flow rate of the leakage flow and the blowing ratio were proposed. With different rim widths, the effect of different global blowing ratios of M=0.5, 1.0 and 1.5 is investigated. In addition, calculation results of squealer tip and flat tip were compared. The simulation results are validated with some limited experimental data in the open literatures.