升力风扇系统参数匹配及工作特性分析

Through force analysis and thermodynamic process analysis， a component-level performance calculation model for the lift fan system was established. The impact of design parameters on performance was analyzed， and based on this， a preliminary design method for the lift fan system was proposed. By deriving the common working equations and calculating the common operating lines through numerical methods， the characteristics of the lift fan operating lines and the influence of various parameters on these lines were examined. The altitude-speed characteristics and lift adjustment characteristics of the lift fan system were calculated， and a multi-parameter joint control law for lift adjustment was proposed. The results show that the performance calculation model’s results are consistent with the trends of CFD simulation results; increasing the design flow rate and pressure ratio can enhance lift，but a high pressure ratio design may lead to reduced lift efficiency. As the rotational speed decreases，the working line gradually disperses from a power function of converted flow rate and pressure ratio into a cluster of curves related to Mach number， with the steady-state and dynamic operating lines being essentially consistent. The multi-parameter joint control law can adjust the lift of the lift fan system while maintaining constant rotational speed and margin.