Numerical Analysis for Optimization of the Lifetime Characteristics of Radial Wheels Turbomachines by Introducing the Intentional Mistuning Parameters

Abstract

Due to manufacturing tolerances, small deviations in the mass of the blade always introduce changes in the geometry and structural properties of the design. Changed geometry and parameters of the blade significantly affect the characteristics of the wheel and the performance of the design of the entire turbomachine. These deviations break the cyclic symmetry of the turbine wheel and are called system mistuning. Generally, the tighter the manufacturing tolerance, the smaller the blade mass deviation. However, if the manufacturing tolerances are tighter, then the manufacturing cost becomes higher. Therefore, in the manufacturing process, the manufacturing cost has an impact on the efficiency and durability of the overall turbomachine. To analyze the problem of the influence of manufacturing tolerance and the cost of manufacturing the wheel, this paper analyzes the type of blade arrangement and mass deviation at the level of block arrangement of blades along the disk rim (block model). The idea is that each block model provides a uniform structure in terms of weight (the unbalance value of the radial disk), can significantly reduce vibration during operation compared to using a blade with a mass deviation. The analysis of the obtained results showed that the introduction of intentional mistuning parameters significantly affects the durability of the radial wheel. The process of optimizing a radial wheel consists in introducing intentional mistuning parameters to manage the resource and ensure the required level of strength, reliability and durability of radial turbomachines.