Analysis Of Structure And Flow Field Characteristics Of Complex Profile Screw Rotor

As a kind of widely used volumetric compressor,screw compressors rely on the high-speed rotation of the female and male rotors to complete gas compression during the working process.Compressor rotor,as the core device of the compressor,directly determines the performance of the compressor by its structure and flow field characteristics.Firstly,finite element analysis method is used to study the characteristics of modal and harmonic response structures of the rotor.Then,combined with the fluid solution and dynamic grid technology,the distribution of pressure,temperature,and flow velocity of the screw compressor cavity in the actual work was simulated.Finally,the fluid-solid coupling analysis method was used to obtain the structural characteristics of the rotor with fluid-solid coupling.The specific research content of this article is as follows:1.By scanning the profile of the screw rotor end face,the end face data of the rotor model is obtained,and the three-dimensional model of the screw rotor is established by using PROE software.Based on the modal analysis theory,the natural frequency and mode shape of the rotor free mode and prestressed mode are obtained,respectively.Finally,the harmonic response of the screw rotor is analyzed.The results,to some extent,can provide a theoretical reference for how to avoid resonance in the actual working process of the rotor.2.The two-dimensional and three-dimensional flow field analysis model of screw compressor was established at first.Then,by studying the screw rotor flow field solving technology,grid generation and dynamic grid technology,the distributions of the pressure,temperature,and air velocity of the screw compressor chamber are analyzed during a meshing cycle.By adjusting the center distance between the male and female rotors to adjust the meshing gap,the variation curves of the pressure,temperature,and gas flow rate in the compressor chamber under different meshing gaps are obtained,moreover,the influence of the gap between the female and male rotors on the performance of the compressor are analyzed.Finally,the pressure,temperature and flow velocity curves of the screw compressor at the same position in the inner cavity of the screw compressor at different speeds and different exhaust end-face clearances are analyzed,and the influence of different rotor speeds and different exhaust end clearances on the performance parameters of the compressor are obtained.3.The two-dimensional and three-dimensional flow field analysis model of screw.Based on the study of fluid-structure coupling analysis technology,a screw rotor fluid-solid coupling analysis system is established.The aerodynamic force distribution of the rotor tooth surface is obtained by simulating the internal flow field of the screw compressor.While applying the rotor aerodynamic force as a load,the stress,strain,modal and harmonic response curves of the screw rotor at 500 Hz-6000 Hz are analyzed,and the results are compared with the structural characteristics of the screw rotor without considering the rotor aerodynamic loading.The research results have a certain theoretical reference for optimizing the structure of the screw compressor and improving the performance of the compressor.