Geometric parameters measurement for the multi-view internal fusion morphology of turbine blade cooling holes

The evaluation of the film cooling performance of turbine blades necessitates the analysis of the geometric parameters of the cooling holes. Nevertheless, obtaining precise measurements poses a challenge due to the intricate structure of the cooling holes, especially the fan-shaped cooling holes with tiny diameters, to which conventional measurement methods cannot be applied. The paper presents a novel method for measuring the multi-view internal fusion morphology of cooling holes, aiming to evaluate geometric parameters accurately, which utilizes the optimal beluga whale optimization (OBWO) algorithm and a weighted variance algorithm that relies on the depth information of point clouds. Experiments simulating the cooling hole process are conducted to validate the proposed methodology. The findings indicate that the method effectively recovers the internal 3D shape of the cooling hole. The above method is also employed to quantify intricate fan-shaped cooling apertures on physical turbine blades. The cooling hole diameter exhibits a maximum error of less than 9.5 mu m, while the hole axis angle demonstrates a maximum deviation of less than 0.87. The proposed method accomplishes the measurement of the internal morphology of the cooling hole and evaluates its geometric parameters.