Enhanced Design of Piston Cooling Nozzles via Computational Fluid Dynamics

To elucidate the relationship between the flow rate of an engine's piston cooling nozzle and its internal structure, a structural model of the piston cooling nozzle and a three-dimensional model of the internal flow field were established through an analysis of the nozzle's structural characteristics and operational conditions. Flow field simulations were conducted using Fluent software, yielding velocity and pressure distribution maps as well as flow rate data within the fluid domain of the piston cooling nozzle. Additionally, the variation in flow rate with changes in the nozzle throat length and diameter was investigated. It was found that the flow rate decreases linearly with an increase in nozzle throat length, while it exhibits a nonlinear increase with an increase in throat diameter. Compared to changes in throat length, modifications in throat diameter have a more significant impact on the flow rate of the piston cooling nozzle. An analytical expression for the flow rate as a function of throat diameter was also derived, providing valuable insights and guidance for the engineering design of nozzles.