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为了预测与评估反推状态下,反推气流再吸入对大涵道比涡扇发动机气动稳定性的影响,采用反推气流扰流流场三维CFD数值模拟、发动机整机稳定性计算分析以及反推状态下发动机进气畸变台架试验相结合的方法,开展了反推气流对大涵道比涡扇发动机气动稳定性影响的研究。通过三维CFD数值模拟手段,捕获了反推状态下发动机进口流场的畸变程度。在此基础上,通过采用稳定性计算程序预测了发动机的气动稳定性,并进一步通过发动机台架试验,验证了预测结果。CFD计算结果表明,随着相对来流马赫数的减小,反推气流被发动机重新吸入的可能性不断增大,当相对来流马赫数减小到0.05时,外侧发动机进口的流场畸变情况变得最为严重。进气畸变情况下的整机稳定性计算分析以及发动机台架试验结果表明,在所考核的目标状态,若只存在因反推气流再吸入引起的进口流场畸变,是不会导致发动机失稳的。
In order to predict and evaluate the aerodynamic stability of a turbofan engine with large bypass ratio under the condition of reverse thrust, the CFD numerical simulation of spoiler flow field, Thrust state of the engine intake distortion test method to carry out a combination of reverse thrust airflow on large bypass ratio turbofan engine aerodynamic stability of the study. The three-dimensional CFD numerical simulation method captures the degree of distortion of the inlet flow field of the engine under reverse thrust. On this basis, the aerodynamic stability of the engine was predicted by using the stability calculation program, and further the engine bench test was carried out to verify the prediction results. The CFD results show that as the relative Mach number decreases, the probability of the reverse thrust gas being re-inhaled by the engine increases. When the relative Mach number decreases to 0.05, the distortion of the flow field at the outer engine inlet Become the most serious. Computational stability analysis and engine bench test results show that in the target state of the test, if there is only distortion of inlet flow field caused by respiration of reverse gas, it will not lead to engine destabilization of.