某型发动机喘振特征分析及消喘系统验证试验

Investigation of surge characteristics and surge eliminating system verification based on a certain engine

分别采用吊舱进口安装扰流板和提高发动机慢车以上状态供油量进行某型发动机地面逼喘试验,研究了两种方法的特点,分析了喘振过程中发动机参数变化情况和喘振原因.结果表明,安装扰流板间歇缓推油门杆和提高供油量快推油门杆逼喘试验均能够有效反映干扰因子对发动机稳定性的影响:安装扰流板后的加速过程中,总压畸变和空气流量减少引起喘振,前者是主要因素,风扇先喘压气机后喘;提高供油量后的加速过程中,燃烧室油气比始终偏大,稳定工作裕度降低,高压燃气堆积并堵塞了空气流,压气机和风扇先后喘振.喘振过程中消喘系统可靠投入工作.获得了该型发动机的临界畸变指数.为该型发动机空中逼喘试验及稳定性评定奠定了基础.

Ground test of surge inducing based on a certain engine was performed separately by installing disturbed board at inlet and increasing the fuel delivery.Characteristics of the test methods,the engine parameters in the process of test and the reason of surge were analyzed.The test results show that intermittently pushing staff slowly after installing disturbed board at inlet and pushing staff suddenly after increasing the fuel delivery are effective methods,which could reflect impact of influential factors on engine stability.By accelerating after installing disturbed board at inlet,the total pressure distortion and reduction of air flow result in engine surge,and fan surge occurs before the compressor;however,after increasing the fuel delivery,gas oil ratio is always bigger along with engine acceleration so that the stability margin of combustor is lower,and air provided for engine is jammed by high-pressure gas of combustor so that compressor and fan surge occur successively.Surge eliminating system reliably works and critical distortion of the engine is obtained.The studies in this paper have established a necessary basis for surge inducing test in the air and stability assessment.