Film Boiling Conjugate Heat Transfer during Immersion Quenching

Round 1

Reviewer 1 Report

The topic of the considered paper is relatively actual. Overall, the manuscript is well prepared. Language is clear and easy to understand, the structure is well organized. However, authors should provide more details about the choice of used parameters and sub-models. So I recommend publication of this paper after minor revision.

 

Lines 164-172. Is it really important to take into account the bubbles-induced turbulence? How was model constants chosen here?  Please provide more details.

1.     Line 199. Why the authors consider Sauter diameters, not equivalent? Usually this parameter is used for sprays and droplet-flows, not for bubbles.

2.     Lines 299-301. It is not fully correct. The natural convection also takes place at Tw > Tsat, since nucleate boiling starts from Tonb > Tsat (as marked in table 4).

3.     Please provide more details about equation (17). How was kMHF and kburn identified?

4.     Lines 351-356. How was Z in (22) defined to be 4? Why [49] was chosen to calculate bubble departure diameter? The same is for N for fw.

5.     The main question is about the comparison with the experimental data of [18]. How «universal» they are? I mean could the described approach be used for other initial parameters?

6.     Did the authors compare their approach with other ones?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The reviewed paper concerns the boiling process during the contact of a hot solid with a cold liquid. This phenomenon occurs during the immersion hardening process used in industry. The authors attempted to model this phenomenon using specialized computer fluid dynamics software. A model of the physics of the phenomenon was developed based on the equations of conservation of energy, momentum, and mass. While the main focus was on film boiling, bubbly and transient boiling were also considered. Various heat transfer mechanisms, additional interfacial forces are taken into account. Separate energy equations were written for each fluid phase, including phase transitions at their interface. Numerical calculations were performed for a simple geometry in the form of a horizontal hot plate placed in a cold liquid. The obtained results are given in the form of dependencies describing the parameters of the boiling process (mainly temperatures) as a function of time.

Critical remarks:

1. The authors of the paper refer to the works of various authors and suggest that they have experience in the study of film boiling on a hot surface. However, there are no publications in this regard in the literature list. There is only one item [2] that is practically not directly related to the subject of the work. If the authors have previous papers on the subject of the reviewed publication, they should be cited.

2. The authors present in Figs. 4 and 9 a comparison of the results of theit own calculations with the results of experimental research. In the description of Fig. 4, they refer to the publication [18] (Khalloufi, M.; Valette, R.; Hachem, E. Adaptive Eulerian framework for boiling and evaporation. Journal of Computational Physics 669 2019, 401) wrote that "These are also in excellent consensus with the numerical validation solution". The provision given in this way shows that the validation was done by computer, and not by experimental tests in laboratory conditions. This should be clarified in the paper. If there are no results from laboratory tests, the paper should be supplemented with studies by other authors or their own studies. Only such validation will show that the results of numerical calculations are actually related to reality.

I suggest introducing the proposed supplements into the paper and publishing the reviewed paper after a positive assessment.

Author Response

Please see the attachment

Author Response File: Author Response.pdf