Analysis of conjugate heat transfer characteristics of nozzle in middle-high speed marine diesel engine

The nozzle temperature characteristics of middle-high speed marine diesel engine affect the reliability of fuel supply system. It is difficult to obtain the accurate temperature distribution of the nozzle in the experiment. This paper is based on the coupling method of multiple physical fields. In this paper, a three-dimensional simulation model is established. The fluid-solid coupling conjugate heat transfer of nozzle was analysed by ANSYS FLUENT commercial software. The results show that the fuel flow rate is 51.24 L/min, the pressure drop mainly occurs in the orifice, and the temperature increases by 1.2 K. The flow rate of lubricating oil is 4.524 L/min, and the pressure drop mainly occurs in the cooling ring cavity. The temperature increased by 4.3 K. The needle body temperature near the fuel area and the nozzle tail is lower, and the nozzle head is higher. The highest temperature is 610.8 K and the average is 511.2 K. The cooling parameters of needle valve body can ensure that the maximum temperature is less than 610.8 K, and the material can still maintain high strength.