Numerical Study Of The Vibration Of Compressor Blade Induced By The Wake Of The Inlet Probe Support

At present,most of the researches on the immersed probe used in turbomachinery at home and abroad focus on the influence of the probe support wake on the aerodynamic performance of the compressor,however,little attention has been paid to the influence of probe rod wake on the vibration characteristics of compressor blades.During a compressor performance test,it was found that if a probe with a diameter of 10 mm was installed at the inlet of the compressor,the dynamic strain of the rotor blade would cause an over limit alarm.However,if the probe was removed or the combined probe with a diameter of 8 mm + 3 mm was replaced,the over limit alarm would disappear.In this paper,a numerical study was carried out for this phenomenon.Numerical simulation was used to study the flow mechanism of blade vibration strain overrun and the influence of inlet probe strut layout on blade vibration,which provided theoretical guidance for the establishment of test layout scheme of probe strut to avoid compressor blade vibration.First of all,the modal analysis shows that the vibration strain overrun of compressor rotor blade under the influence of strut wake is a resonance problem.Then the feasibility of harmonic response analysis,one-way fluid structure interaction and two-way fluid structure interaction to describe the compressor rotor resonance is compared,therefore,the numerical method in this paper is one-way fluid structure interaction.Then,the influence of the probe free strut on the vibration characteristics of the compressor rotor blade under the condition of rotor blade failure is studied by using the one-way and two-way fluid solid coupling calculation methods.Both methods can predict that the strain fluctuation of rotor blade decreases with time and no resonance failure occurs.Thirdly,under the fault condition,the influence of rod wake of 10 mm and 8 mm + 3 mm probes on the vibration characteristics of rotor blades and the flow mechanism of resonance failure induced by strut wake are analyzed in detail.It is found that the frequency of blade resonance comes from the superposition of the fluctuating frequency of rotor inlet angle of attack caused by the wake of probe strut and the passing frequency of strut,and The fluctuating frequency of the angle of attack of the rotor is determined by the frequency of the shedding vortex,the transport time of the shedding vortex,the passing frequency of the strut and the rotor.Finally,based on the failure condition,the effects of the number,axial position,circumferential position and diameter of the probe strut on the vibration of the compressor rotor blades are studied.In the case that the interaction between the probe rods can be ignored,reducing the diameter of the probe rods can significantly reduce the its wake strength and avoid the rotor blade resonance failure.Increasing the axial distance between the probe rods and the rotor and changing the circumferential position of the rods will not greatly improve the vibration performance of the rotor blades.