The calculated effect of combined distortion on the engine stability shows that the critical values of pressure and temperature distortion are 8.82% and 8.60% respectively.The pressure distortion coefficient of the fan is 2.608 and the temperature distortion coefficient of the compressor is 2.442.The magnitude of pressure distortion and temperature distortion determines the severity of the combined distortion effect on the fan or compressor stability.When the relative peak intensity of distortion appears at the fan section
the fan falls into instability first
otherwise the compressor does.The effect of the combined distortion on engine stability can’t be calculated by superposing the effect of the pressure distortion to the temperature distortion simply