Impingement Cooling 2

[borjame]

I'm looking for some data or correlations concerning impingement cooling. I'm looking to at how my h will vary with different shaped impingement holes, slots, etc and the shape of the impinged surface (ribs, rough surface, etc). Thanks.

 

[poetix99]

I suspect that various "industries" that utilize impingement cooling have developed their own specialized correlations, and it would be well worthwhile to investigate those (if applicable).

In any case, I will say as a more general statement that the shape of impingement holes does not matter directly, but could affect "h" by determining the cooling fluid velocity distribution.

Surface details of the hot body will also affect this of course, but the orientation of the hot body surface(s) are also potentially very important. I think that changing the surface for the sake of improving the cooling is unnecessary...

I believe that you could consult standard heat transfer texts to obtain some useful correlations (Rohsenhow & Choi, Holman,...), but you will have to grind through a lot of calculations if your configuration is irregular (cooling flow, surface orientation, temp. difference, etc.) in order to obtain some sort of average "h" value(s).

 

[rjw57]

borjame

Best reference I have seen for this topic is entitled "Heat and Mass Transfer between Impinging Gas Jets and Solid Surfaces" by Holger Martin. I believe that the professor can be reached here (possibly to discover where this publication could be found or if its still in print form): Holger.Martin@ciw.uni-karlsruhe.de
Perhaps you could ask for a suggestion on a book/paper closer to what you have described since this one deals with singular and arrays of either round or slotted jets. The book appears to have a section which may relate to your question regarding surface effects. It is called "Other parameters Influencing heat and Mass Transfer" and is broken down further into A) Turbulence Promoters. Swirling Jets. B) Wire Mesh Grids on the Surface of the Material. C) Impinging Flow on Concave Surfaces. D) Angle of Impact. The book also has a reasonable reference list at the end.

Also, from Feb 1966 "Journal of Heat Transfer" there is an article entitled "Heat Transfer Characteristics of Impinging Two-Dimensional Air Jets" by Robert Gardon and J. Cahit Akfirat. I assume you could get a reprint from the Linda Hall Library (ASME site has links).

Next is "Heat Transfer Between a Flat Plate and Jets of Air Impinging on It" by Robert Gardon and John Cobonpue. I don't have any idea where this came from but it is numbered "53". Looks journalish to me though.

Last is "Heat Transfer by Convection from a Hot Gas Jet to a Plane Surface" by K.P. Perry. Again, not sure where this came from but an internet search might help...

If you intend to do internet searches on this topic also check for the names Petzold, Gnielinski and Schlunder. They seem to have done related work.

rjw57