Research on the volume-based fully coupled method of the multi-fidelity engine simulation

Numerical simulation is an indispensable means to develop advanced aero engines. To improve the simulation accuracy of aero engines under limited computing resources, coupling methods are commonly used to investigate the multi-fidelity engine simulation. However, for complex high-precision component models, the obvious problem in the application of existing methods is reflected in the high computational cost. Through the investigation of a single-spool split-flow turbofan engine, this paper presents a rapid and accurate coupling method to research the multi-fidelity simulation of three-dimensional component models and zero-dimensional engine model, which creatively combines the advantages of the volume method and the fully coupled method. Then, through numerical examples of the turbofan engine and another single-spool turbojet engine, the volume-based fully coupled method is compared with the existing coupling methods in terms of accuracy, computational cost, and simplicity. Moreover, the experimental data of the ground test and high-altitude test are performed to verify the effectiveness of the coupling methods. And the results indicate that the volume-based fully coupled method matches well with the test data. For the numerical examples of the turbofan and turbojet engines, the volume-based fully coupled method consumes 56.74 and 39.17 hours to realize the multi-fidelity simulation respectively. And the former example reduces the computational burden by 52.76% and 38.12% respectively compared with the existing iterative coupled method and fully coupled method. While the latter example saves the computational cost by 50.11% and 36.28%. The main novelty of this paper lies in that it affords an effective solution capable of significantly decreasing the computational burden of the multi-fidelity simulation model based on guaranteeing simulation accuracy. Moreover, it fully embodies the design idea of the whole engine guiding the engine components, and it could provide more realistic requirements for component design during the design phase of future new concept aero engines in the absence of component characteristics.