Study of parameters affecting the cooling capacity of liquid jets by using OpenFoam as tool to solve the inverse heat transfer problem

Abstract: In this work, some of the parameters influencing the cooling capacity of a liquid jet impinging onto Inconel 718 and C45 plates were experimentally investigated. The experiment included a high-speed camera to record the dynamic of the jet during the cooling process while an infrared camera was used to record the temperature field at the opposite surface. Jets made of water and oil-in-water emulsion were analysed as well as the influence of the oil concentration. Other parameters studied here include initial temperature of the plate, nozzle-to-plate distance, nozzle diameter, jet velocity, and impinging angle. The cooling performance was analysed by solving a full 3D inverse heat transfer problem (IHTP) with the Conjugate Gradient Method (CGM) implemented in a new solver in OpenFoam. The basic organization and implementation of the solver is shown, followed by its validation with a made-up case. Finally, the growth of the wetting front was analysed for different oil concentrations and a combination of nozzle diameters and jet velocities for the same flow rate. For the latest, unexpected results emerged when comparing the wetting growth for the two plate materials.