The Dynamic Behaviors Of Journal Bearing-rotor System With Micro-polar Fluids

Bearing-rotor system as a core component of rotating machinery have played an important role in energy, power, petrochemical, and the fields of national defense, etc. Many researches have shown that micro-polar fluids can effectively reduce wear of the bearing-rotor system than Newtonian fluids. Micro-polar fluids plays an important role in modern science and technology, polymer additives containing oil, fluid with minor additions, ER fluids, liquid crystal and blood belong to micro-polar fluids. The rigid Jeffcott rotor with micro-polar fluid as the research object, studied the nonlinear dynamical behavior of journal bearing-rotor system under different parameters by using numerical integration. The motion morphological of the system is studied by combined bifurcation diagram, Poincare map, time history map and spectral analysis. Paper got the following useful results:Firstly, through micro-polar principles deduced Reynolds equation of bearings-rotor system with micro-polar fluids. The Reynolds equation with micro-polar fluids is solved by the variational method. The dynamics model of finite width rigid Jeffcott rotor system is dived.Secondly, using the fourth-order Runge-Kutta algorithm to solve the differential equations of motion of the rotor system, and use Fortran programming to analysis of this system, got bifurcation diagram about dimensionless speed ω and analysis chart at some point in wide aspect ratio, the results shown that this system has a wealth of nonlinear dynamics, micro-polar fluids can effectively improve the stability of system.Thirdly, the impact of the micro-polar parameters L0 and N to nonlinear motion characteristics of finite width rigid Jeffcott rotor is discussed, got bifurcation diagram about micro-polarity parameter L0 and N and analysis chart, results shown that Micro-polar parameter has a significant influence on the motion characteristics of the system. This needs to be confirmed by further experiments or field observation.Finally, this paper summarizes the results achieved, and pointed out the shortcomings of the innovation in this paper provide a direction for future work.