| An aero engine is a device that provides thrust for an aircraft.In terms of optimizing its performance,usually for the purpose of improving work efficiency,reducing the radial clearance between the blade tip and casing is the most commonly used method at present.With the gap decreases,the chance of the rotor system blades rubbing against the casing greatly increases.Rubbing will cause complex vibrations during the operation of the system,which will cause the system performance and the life of the blades and casings to decrease,which will cause major safety issues and economic losses.In this paper,the aero-engine compressor disk is used as the research object,and the finite element method is used in ANSYS software to conduct a comprehensive study of the blade-casing impact law.Firstly,a solid model of the compressor blade disk and a simplified finite element model of the elastically supported blade-rotor coupling are established.The combination of the dichotomy and the finite element method is used to introduce the mistuning of the blade elastic.modulus.The full-circle rubbing dynamics of a mistune blade rotor system is analyzed,and the three parameters of the blade elastic modulus mismatch standard deviation,speed and rubbing clearance are compared and discussed.Then,based on the existing finite element model,a casing model was added,and the dynamic response of the mistuned blade disk and casing rubbing was studied by defining the surface-to-surface contact.Under different operating conditions,the effects of the two parameters of the blade elastic modulus mistune standard deviation and speed on the dynamic response of the system’s rubbing are compared and studied.A finite element model of bladecoating casing rubbing is also established.The effects of coatings on the system rubbing process are compared and studied without considering the coating abrasion and thermal effects.Finally,a solid model of the straight blade-casing system and a simplified model of the finite element of the rotating shaft-straight blade-casing were established.A 5 degree crack gap was established at the root of the exhaust edge of one straight blade,and different constant impacts were applied.The mechanical characteristics of a single cracked blade were analyzed by friction load,and the variation law of stress intensity factor was obtained.The rubbing dynamics of an impeller-casing system with straight plate cracked blades was analyzed by defining surface-to-surface contact,and the effect of the system on the cracks during rubbing was studied. |
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