ЧИСЛЕННАЯ МОДЕЛЬ ОГНЕНЕПРОНИЦАЕМОСТИ ЭЛЕМЕНТОВ ГАЗОТУРБИННЫХ ДВИГАТЕЛЕЙ ИЗ АЛЮМИНИЕВЫХ СПЛАВОВ

Abstract

For the early stages of design, a numerical model of fire resistance and fire permeability of GTE elements made of alu-minum alloys is proposed. The numerical model is based on the solution of three-dimensional Navier-Stokes equations, closed by a two-parameter isotropic SST – turbulence model. We used an implicit pressure solver and a scheme of second-order accuracy in High Resolution space, which allows lowering the approximation order to the first in the areas of solution discontinuities and high gradients to increase the monotonicity and stability of the solution. Additionally, to achieve the solution stability, the High Speed Numerics solver option was used, activating the solver settings Gradient Factor Relaxation = 0.1 and Blend Factor Relaxation = 0.1. The mathematical model for the thermal-hydraulic calculation was set up in the formulation of the coupled heat transfer, taking into account radiation based on the discrete transfer model of the Participating Media. The influ-ence of the degree of blackness on the results of the numerical model is investigated and the most rational radiation model is chosen. The numerical model was validated according to the results of engineering tests on the fire permeability of the plate not cooled by the air flow using a kerosene burner NexGen of the bench Ts17-G3 of FAU P.I. Baranov TsIAM. The obtained results of calculations on fire permeability are comparable with the experimental data both quantitatively and qualitatively. The developed un-steady numerical model of fire permeability of flat plates of aluminum alloys under conditions of free convection can be used in the de-sign of the fan housing by selecting the most rational structural and layout solutions, such as the thickness of the housing, the presence of fire protection coating, cooling intensity, etc.