Nomenclature: A = Target plate surface area, [m.sup.2] [A.sub.h] = Hole cross-sectional area, [m.sup.2] D = Jet hole diameter, m H = Jet to target spacing, m [h.sub.av] = Averaged heat transfer coefficient, W/[m.sup.2].k k = Thermal conductivity of the target plate, W/m.K [m.sup.*] = Mass flow rate, kg/s Nu = Nusselt number [bar.Nu] = Area-averaged Nusselt number Q = Heat flow rate, Watt Re = Reynolds number S = Jet to jet spacing, m t = thickness, m T = Temperature, degree centigrade Tw = Wall temperature, degree centigrade X = Local length of the target plate, m [bar.[eta]] = Average wall cooling effectiveness [rho] = Density of the air, kg/[m.sup.3] Subscript: s = crossflow av.= average in = inner target surface j = jet out = outer target surface [infinity] = mainstream flow REFERENCES
"Effect of Jet Hole Arrays Arrangement on Impingement Heat Transfer" M.Sc.
Azad et al , Used line jets array (four row with each row having twelve jet holes) impinging orthogonally on pinned target surface and observed the heat transfer is increased greatly.