In heat treating industry cooling curves analysis is widely used for controlling quenching processes. Special standard probes with one thermocouple at the core are used to control intensity of cooling. Such analylisis cannot provide enough data for computer simulation of the quenching processes. Many investigators use CFD modeling trying to apply it to transient boiling processes taking place during quenching. Is there any success in this field?
No success can be without taking into account critical heat flux densities for each specific quenchant. As known, critical heat flux densities are not yet investigated enough for many quenchants, that is why big problem will arize when apply CFD modeling to transient boiling processes. And also other theoretical and practical problem will ocuur in this field.
If you plan to simulate using CFD, the flow of quenchant and resulting heat transfer, then I must say that the problem is difficult. There have been some CFD studies for electronics cooling utilizing the quenching concept. I am curious to know how do you plan to use temperature data for CFD simulation, or do you mean validation?
We used CFD for solving conjugate problem when quenching steel parts of different shapes from 860oC in water flow which provides direct convection during quenching. Water flow was high enough that liquid had no chance to be heated to boiling point. We assumed that It was no boiling from the very beginning. However, water flow creates stagnation zones when quenching, for example, shaft consisting of different diameters. In stagnation areas even film boiling can start if heat flux q>qcr1. It means that we should compare heat flux with the critical heat flux density in this area. I don't believe that CFD technique can be used successfully for investigation boiling processes as many investigators trying to do. Boiling processes are too complicated. I believe that CFD can be used for solving conjugate problem when direct convection is provided during quenching ( see US Patent # 6, 364, 974 B1).
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