Multi-Fidelity Simulation Research On the Low Reynolds Number Effect On the Engine Performance At Different Altitudes

With the rapid development of unmanned aerial vehicles, the effect of low Reynolds number on gas turbine performance has received extensive attention. However, the existing three-dimensional component modeling cannot meet the design requirements of the whole engine level. Through the study of a single-shaft turbojet engine, this paper adopts a fast and accurate coupling method, which combines the volume method and the full coupling method, and conducts multi-fidelity simulation research on the zero-dimensional engine model and the three-dimensional component model. Then, based on the high-altitude test data, compared with the existing empirical correction method in GasTurb, the accuracy of the engine inlet flow, fuel flow, thrust, and exhaust gas temperature predicted by the volume-based fully coupled method is improved by 6.2%, 7.9%, 4.7%, and 11.4% respectively. Next, as the flight altitude rises from 0km to 21km, the working lines approach the surge lines, the maximum mass flow rate and the efficiency of the engine components gradually decrease. In addition, in the flow field of the components, the thickness of the boundary layer increases, the shock wave intensity decreases, and the position moves forward. The core innovation of this article is that it provides a creative multi-fidelity evaluation method for gas turbines to effectively solve the problems of insufficient accuracy of the existing empirical correction methods and the inability of the component design to meet the gas turbine requirements in the study of low Reynolds number effect.