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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Based on the obtained displacements, a three-dimensional conjugate gas-dynamic calculation of the blade with the TC real shape was carried out. It is expected that due to the uneven heating of the rotor and stator parts in the axial direction, as well as the influence of fits of conjugate parts, the gap will be uneven in the axial direction. Also, the TC unevenness is formed in the circumferential direction when the blade deviates towards the back under the action of gas-dynamic forces (Inozemtcev A.A., Nihamkin M.A., & Sandratckij V.L. 2008). These deviations from the uniform TC, which is commonly used in gas-dynamic calculations of turbine blades, will presumably lead to a change in losses and the structure of secondary flows.

Nomenclature GTE

gas turbine engines combustion chamber

CC PS TC SS

pressure side tip clearances suction side

SSS TFC

stress-strain state typical flight cycle

2. Tip clearance real form determination

At each moment of time on a working gas turbine engine, the real RС consists of the following components, shown in Figure 1: • mounting TC- tip clearance on a non-working engine; • the stator displacement - leads to an increase in the real TC ; • the rotor and blades displacements - lead to a decrease in the real TC.

Fig. 1. TC dimensional chain.

As described earlier in the introduction, to determine the TC actual shape, it is necessary to determine the thermal state and radial displacements of the rotor, stator, and blade. 3. Rotor displacement The disks interlocking parts displacement non-uniformity at the RB attachment place was determined based on a non-stationary thermal calculation according to the TFC with the subsequent calculation of the SSS. The thermal state is determined based on axisymmetric finite element models. The non-stationary problem of heat conduction is solved for complex composite regions with contact heat exchange and third kind boundary conditions (heat transfer coefficient and ambient temperature). Based on the obtained thermal state, an axisymmetric calculation of the SSS was performed. For reliability, the rotor assembly (shaft, disks, intermediate disks, deflector, rings) is considered, since the elements adjacent to the