Numerical Simulation of Subcooled Nucleate Boiling in Cooling Jacket of IC Engine

There has been a change in the thermal management of IC engines where engineers now like to harness the superior heat transfer rates available when limited and controlled nucleate boiling is used to remove heat from high temperature zones. Any flaws in the design of such systems, such as uncontrolled boiling that leads to Dry Out situation, can have an adverse effect on the cooling performance. A detailed engineering model of this process would allow engineers to weed out flawed designs early in the design process. In this paper, we proposed and validated a CFD model for this process.

A CFD model is built using the commercial CFD solver ANSYS FLUENT. The mixture multiphase model is used to study subcooled nucleate boiling in IC engine cooling jackets. The departure of bubbles enhances heat transfer at walls, which is captured using the empirical correlation. Volumetric mass transfer is modeled using the inbuilt evaporation-condensation model. Results obtained from heat transfer in channels are compared with experimental results available in the literature for a range of operating pressures, different inlet sub-cooling and different inlet flow velocities. The predicted heat fluxes are in good agreement with experimental data. Results from a typical I.C. engine cooling jacket geometry are also presented.