PSI - Issue 50

Diana D. Popova et al. / Procedia Structural Integrity 50 (2023) 236–250 Popova, Popov, Samoylenko / Structural Integrity Procedia 00 (2022) 000 – 000

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From the graph in Figure 7, it can be seen that the maximum reduced TC value is observed at the RB leading edge, and the minimum is at the trailing edge and part of the suction side. For each section, a generating line is constructed by shifting from the case by the value of the reduced TC value at each of the two points, as shown in Figure 8. Thus, lines are obtained in the sections that are generatrices for creating a surface of complex shape, which will later become a new end surface of the blade considering unevenness.

Fig. 8. The TC real shape construction in the section, taking into account the non-uniformity.

The original RB end surface was replaced with a new one with constructing the design geometry; the result is shown in Figure 9. A similar form of clearance for the compressor is considered in (Botao Zhan et al. 2022), however, it was not due to real deformations.

Fig. 9. RB end: red - new surface; blue - old surface.

Under the influence of all external factors, it is shown that in real conditions the tip clearance non-uniformity is quite high (the difference is more than 2 times at different points along the profile), and the blade end surface is not parallel to the case, as it is commonly assumed in the turbine blades three-dimensional gas-dynamic analysis. 7. Turbine stage three-dimensional gas-dynamic modeling with a TC real form. Computational domain, boundary conditions and problem statement The computational domain is shown in Figure 10; it includes the inlet and outlet paths, as well as the nozzle and rotor blades that form the turbine stage.