The Effect of Nozzle Configuration on Local Convective Heat Transfer to Horizontal Plate Impinging Air Jet

In an impinging air jet, nozzle shape noticeably impacts heat transfer between jet and plate by affecting the velocity profile at the jet exit and thereby potentially modifying the behavior of the air jet vortex structures. This study analyzed the influence of four different injections (۰ to ۸۰ mm). They all possess the same free area and the equivalent diameter is D = ۹ mm. Experiments have been conducted for Reynolds numbers ۱۹۲.۶۱< Re<۱۶۶۱.۲۶, for orifice-to-plate distances ۰.۶۷ < H/D< ۱۶, and for the temperature of the jet was conducted ۱۱۵oC. In this effect which is greater in the round shaped orifice was taken. The velocity profile at the jet exit (۶.۴ and ۹.۲ m/s), for a distance from the point of impingement (x/D = ۰ to ۱۶۰) presents a shape for the round orifice (۰.۵ to ۳ mm). Thermal results also show that a round orifice on higher heat transfer rate for injections. The measurements of parameters on the behavior of local heat transfer characteristic values on the impingement surface and the effect of the velocity values were discussed. From the results, it was observed that the peak of the heat transfer obtained at the impinging point higher jet velocity of ۹.۴m/s.

کلیدواژه ها:

Orifice-to-plate spacing ، impinging jets ، Reynolds numbers ، velocity profile ، Plate impinging air jet