Numerical investigation into coolant liquid velocity effect on forced convection quenching process

In this paper, forced convection quenching process of hot pieces in the subcooled liquid is numerically investigated. The Volume Of Fluid method is extended to simulate boiling phenomena and re-condensation of vapor bubbles in the quenching process. The developed CFD code is validated and there is a good agreement between the developed code and existing analytical solution and also experimental data. Quenching oil is selected as the working fluid and liquid-vapor phase is considered incompressible and immiscible. Energy equation in the solid region is also solved to find out temperature distribution within the hot piece. To consider the different flow conditions during the process, forced convection quenching of a step plate at different inlet velocities in the range of 0.1-0.6 m/s is studied. All the simulations are performed in laminar flow region and the effect of oil inlet velocity on some parameters such as variation of temperature with time, heat transfer rate, temperature uniformity index and oil pumping power are investigated. Investigation of uniformity index, heat extraction rate and pumping power parameters showed that 0.3 m/s entrance velocity is the most appropriate choice for forced convection quenching of step plates in small sizes.