Numerical Simulation of Thermal and Hydrodynamic Behavior of Mixtures of Air and Oil in Hydraulic Coupling

Todays, in Power Plant Industries, hydraulic coupling are frequently used for transmission of power from electromotors to pumps and fans. However, because of the oil trap in the coupling and continuous operation the properties of the oil change and early destruction of coupling happens. Consequently, this problem can be delayed by precise analysis of thermal and hydrodynamic behavior of coupling and also using a proper cooling system. Thus, in this paper, thermal and hydrodynamic behavior of a mixture of oil and air in a hydraulic coupling, because of the 3D-geometry and complicated flow, is simulated by FLUENT software. The aim of this study is to identify locations of the secondary flows and vortex which have the greatest role in heat-generation. Also, the areas of fluid and body with high temperature will be determined. In this simulation, the internal flow in the coupling is examined in 3D, two-phase, and turbulent conditions. The velocity and temperature distribution of the fluid flow and the temperature distribution on the body of coupling are analyzed. The results indicate that the maximum temperature is occurred at the outside diameter of turbine coupling, increasing the distance between the pump and turbine increases the thermal dissipation around 65KW and increases the maximum and mean temperature of oil, and displacing the fins can reduce the thermal dissipation around 8KW.