Micropolar fluid to improve dynamic response of gear pair system supported by journal bearings

Abstract

PurposeThe purpose of this paper is to present a numerical analysis of the nonlinear dynamic response of a gear‐bearing system subject to nonlinear suspension effects, micropolar fluid, journal bearing, nonlinear oil‐film force and nonlinear gear mesh force. The results presented in this study provide some useful insights into the design and development of the system for rotating machinery that operates in highly rotational speed and highly nonlinear regimes.Design/methodology/approachThe non‐dimensional equation of the gear‐bearing system proposed in this study is solved using the Runge‐Kutta method. The non‐periodic behavior of this system is characterized using phase diagrams, power spectra, Poincaré maps, bifurcation diagrams, Lyapunov exponents and the fractal dimension of the system.FindingsThe numerical results reveal that the system exhibits a diverse range of periodic, sub‐harmonic, quasi‐periodic and chaotic behaviors. The micropolar fluid is a useful lubricating fluid to suppress nonlinear dynamic responses and improve the dynamic regularity of the systems.Research limitations/implicationsThe unbalance coefficient, damping coefficient, other control parameters and some experiments are also important to identify dynamic behaviors of those systems and they may be regarded as research directions in the future.Practical implicationsBecause of financial constraints, some important experiments are outstanding to identify dynamic behaviors of these systems and await research in the future.Originality/valueThis study has presented a numerical analysis of the nonlinear dynamic response of a gear‐bearing system with nonlinear suspension effects, micropolar fluid, journal bearing, nonlinear oil‐film force and nonlinear gear mesh force.