直升机扭振固有频率测量试验方法

直升机扭振与FADEC控制的耦合具有强大的破坏作用,在FADEC中必须采取有效措施防止这种共振,有必要通过试验的方法测量扭振的固有频率。独创性地设计了用于直升机扭振固有频率测量的新方案:采用颤振扫频技术,直接对FADEC系统动力涡轮转速给定值进行激励,通过闭环系统对发动机动力涡轮转速进行扫频激励的方法,获取了直升机扭振系统不同工作模态下的扭振频率点。试验结果表明:该新方法能够在直升机平台准确地获取扭振固有频率。

Investigation on Test of Helicopter Torsional Vibration Natural Frequency Measurement

The coupling between helicopter torsional vibration and FADEC control has a horribly destructive effect. Effective measures must be taken to prevent this torsional vibration in FADEC. Therefore,it is necessary to measure the natural frequency of torsional vibration by test. A new scheme for natural frequency measurement of helicopter torsional vibration is originally proposed and designed,which excited the given value of power turbine speed in FADEC system by utilizing sweep-frequency technique of shimmy. The torsional vibration frequency of helicopter torsional vibration system is able to be distinguished under different working modes by means of the excitation to power turbine speed of engine through the closed-loop system. The result show that the new scheme can measure the natural frequency of torsional vibration precisely on the helicopter platform.