变循环发动机风车起动建模及仿真研究

In order to meet the requirement of windmill starting simulation for variable cycle engines，a component-level windmill starting model of variable cycle engine was established. To solve the problem of discontinuous isentropic efficiency of rotating components，a method of using corrected torque instead of isentropic efficiency was introduced. The method to expand the full speed characteristics of rotating components was given. A burner stability model that can consider ignition and burn stability was proposed. Considering eight variable parameters of variable cycle engine，differential evolution algorithm was used to optimize the windmill and windmill starting performance of variable cycle engine. The results show that，in the windmill state，variable cycle engine has a higher core physical speed in the single bypass mode，which is beneficial to the core physical speed quickly tending to its idle value after ignition. In the single bypass mode，the variable parameters of variable cycle engine in the windmill state are only related to flying Mach number. In order to maintain a high physical speed of the core，the outer bypass area of rear variable area bypass injector needs to be decreased with the increase of the flying Mach number，and the remaining parameters are fixed at their optimal values. When the flying altitude is 6km and the Mach number is 0.8，the windmill starting time of the variable cycle engine in the single bypass mode is 1.4s. The increase in fuel flow during windmill starting is mainly constrained by the burning stability. By optimizing the variable parameters，the key performance parameters of variable cycle engine during windmill starting can be approached to their limit values to the greatest extent，thereby reducing windmill starting time.