Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects

The paper presents research results of thermal phenomena accompanying operation of a water-lubricated stern tube bearing with axial grooves. Experimental tests revealed, that intensity of forced axial flow has strong influence on bush temperature. Numerical simulations focused on investigation of the thermal phenomena under operation of water-lubricated journal bearing showed, that restricted axial flow promotes backflow of the water from bearing's side zones through the grooves. The backflow temperature is higher than the supply temperature since under the conditions of restricted forced axial flow, it is impacted mainly by the temperature of the water outflow from the gap, which is higher due to the shearing of lubricating film. This effect causes rise in the temperature of the bearing bush. •Thermal effects in water-lubricated stern bearing with axial grooves were studied.•The influence of axial water flow on bearing temperature was tested experimentally.•Complex model of stern bearing was developed with the use of FSI technique.•Backflow phenomenon decides about bearing temperature under reduced water flows.•Heat conduction through the shaft has significant effect on bearing temperature.