基于脉动压力变化率的航空发动机喘振检测方法

Aero-engine surge detection method based on fluctuating pressure change rate

根据发动机发生喘振故障时气流脉动压力会急剧变化这一特征,通过测量和计算压气机出口脉动压力变化率实时检测喘振的发生。对动态压力信号进行预处理以提取特定频段内的脉动压力,计算固定周期内脉动压力变化率;依据发动机整机地面试验结果设定喘振检测阈值及判据,判断脉动压力变化率是否满足判据来实现喘振检测。利用该方法成功检测出发动机飞行试验中的两次喘振故障。分析得出:发动机未发生喘振时,地面试验和飞行试验脉动压力变化率差异很小;发生喘振时,脉动压力变化率绝对值急剧增大;发动机在稳态和瞬态过程稳定工作时,脉动压力变化率不受发动机工作状态变化的影响。

According to the characteristics that the airflow fluctuating pressure will change sharply when the surge failure happens,the occurrence of surge can be detected in real time by measuring and calculat ing the fluctuating pressure change rate at the outlet of the compressor.The dynamic pressure signal was preprocessed to extract the fluctuating pressure in a particular band,and the fluctuating pressure change rate in the fixed period was calculated.The surge detection threshold and criterion was set based on the ground test results of the engine to determine whether the change rate satisfied the criterion to realize surge detection.Two surge failures in a certain engine flight test were detected using this method.Analysis shows that when no surge occurs in the engine,the difference of the fluctuating pressure change rate between the ground test and the flight test is small.When surge occurs,the fluctuating pressure change rate will in crease sharply.When the engine works stably under steady and transient conditions,the fluctuating pres sure change rate is not affected by the change of the engine operation conditions.