Effect of internal unsteady flow of 90 degree bend nozzle with circular cross-section on oil jet behavior

Abstract

Methods of decreasing the CO2 emissions of the internal combustion engine have been suggested. However, these methods generate high combustion temperatures that increase the heat load in general. Therefore, the piston cooling gallery has been proposed as a system for cooling. For supplying the oil to cooling gallery, an oil jet injected from a nozzle placed under the piston flows into the cooling gallery through an entrance hall. It may thus be desirable to control the shape of the oil jet such that it is stable and straight. However, the interface of the ambient air and oil jet may have unstable, and the mechanism is unclear. In this paper, we measured nozzle internal flow using two-dimensional two-component time-resolved particle image velocimetry and visualization of the jet time-synchronously. As the result, we clarified that the characteristic POD (Proper Orthogonal Decomposition) modes of nozzle internal flow makes oil jet wavy.