基于改进增强型本征正交分解方法的航空燃油齿轮泵瞬态内流场重构分析

The specific information about the transient flow field and the flow mechanism of the aero-engine fuel gear pump are important basis for optimal design. This paper presents a reconstruction strategy for the non-linear transient flow field in a fuel gear pump on a shorter time scale through an improved enhanced method utilizing Singular Value Decomposition-based Proper Orthogonal Decomposition（SVD-POD）. The non-linear flow field problem within the gear pump is transformed into a linear problem to enhance the accuracy of reconstruction. Simultaneously，by adjusting and verifying the mechanistic model and experimental data，the accuracy of the POD method is further improved. Finally，with the time correlation function and orthogonal basis obtained from POD，this method is used for predicting the pressure field parameters such as inlet/outlet velocity and tip clearance of the fuel gear pump. Compared to CFD numerical simulations，the simulation time for reconstructing three typical operating conditions has been reduced by 71.7%，69.4%，and 63.2% with equivalent computational accuracy. For the accuracy of the pump inlet/outlet flow field reconstructed by the three-order modes，96% nodes have an error of less than 7.6%，and 77% less than 1%，showing high reconstruction accuracy. The linear heat map and spectrum of the pressure field at 100 time points on the reconstructed tip clearance show that under the working conditions of 9，12 and 15 kr/min，the pressure on the tip clearance varies periodically with the gear rotation，and the frequencies are 1 500，2 000 and 2 500 Hz respectively，which are consistent with the pulsation frequency of the fuel gear pump.