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A Study on Rotor Profiles Design for a Novel Twinscrew Kneader
Jing Wei,Qingchao Sun,Xujian Sun,Wei Sun 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.
The profile curve design method and the mathematical model of conjugate surfaces of twin-screw kneader used for high viscosity material mixing, transportation and malaxating are established according to the principle of gear engagement. A novel twin-screw kneader and the equations of the profile curves of the rotors as well as the rotor design are proposed. The working principles of the twin screw kneader are analyzed and numerical simulations for dynamic characteristics of the flow field are carried out Threedimensional,isothermal and steady state numerical analysis of a non-Newtonian fluid are presented, based on computational fluid dynamics (CFD) theory, and the characteristics under the conditions of different speeds and center distances are studied, such as pressure distributions, velocity fields, the maximum shear stresses and the mass flow rates. The results provide a theoretical basis for performance predictions and reasonable design for the novel twin-screw kneader.
Measured and investigated nonlinear dynamics parameters on bolted flange joints of combined rotor
Tao Li,Dongjian Yang,Binbin Zhao,Qingchao Sun,Junzhou Huo,Wei Sun 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.5
The complex micro-slip phenomenon of the contact interface will lead to the nonlinear stiffness of the connection structure, as well as the structural damping and energy dissipation. As the most important connection structure of the combination rotor, the mechanical properties of bolted flange joint interface are needed in the dynamic analysis of the combined rotor. Therefore, it is urgent to model and test the friction contact interface in the nonlinear dynamic analysis of rotor. In this paper, two sets of mechanical characteristics test system were built to test the dynamic parameters of tangential and bending directions of the bolted flange joint interface. Then, the mechanical behavior and the change regularities of dynamics parameters were studied under different external excitation, bolt distribution and tightening torque. The results show that once the bolt preload is above the rated torque, stiffness softening behavior is not significant; and then the tangential stiffness of the joint interface tends to be stable, with the variation range of 8.08~8.96e8 N/m; the equivalent bending stiffness coefficient is about 3.38~3.83e6 N·m/rad. With the decrease of bolt preload, the external excitation and the number of bolts have a significant effect on the stiffness reduction of the joint. Finally, the change interval of the dynamics parameters of the interface obtained by the experiment provide basis for the uncertainty dynamic analysis and optimization of the rotor.