Impingement Cooling Characteristics of a Cube in Cross Flow

Abstract

An experimental and numerical investigation is carried out for the heat transfer from a cube faces subjected to impinging jet which centrally strikes the top face of the cube. The cube is subjected also to a comparatively low velocity cross flow through the duct occupying the cube. Different factors affecting the cooling characteristics of the cube are studied as orifice size, jet velocity and orifice to cube top distance. The results show that cross flow increases heat rates from the cube for small size orifices and low impinging jet velocities. Orifice sizes equal or bigger than cube size will isolate the cube from cross flow effect especially at high impinging jet velocities.

Experimental Study of Heat Transfer Parameters of Impingement Heating System Represented by Conductive Target Plate of Resistive film

“…As seen from this figure, the inline array enhanced the cooling effectiveness over that of the staggered array by (10.3 %). As stated before, the cross flow created by the jets didn't disturb the next jet that stands in its pathway for inline arrangement while in staggered configuration, the cross flow disturbed the downstream jets, as shown in the figure (13), therefore the impingement jets of staggered array are not active compared with the inline jets array. The variation of average cooling effectiveness ( ) along the flow direction for both arrays is presented in figures (17 to 20).…”

“…For staggered array, it can be seen that the cross flow velocity has a great influence on the impingement jet, where high deflection is observed at the downstream compared with inline arrangements. Figure (13) shows the velocity vectors in X-Z plane for both inline and staggered arrangements. The results show that the channel flow is induced in inline jet arrangements while in staggered arrangement, these channels are not existed.…”

“…Perapong and Chayut [11] investigated experimentally and numerically two arrays arrangements of jets, inline and staggered at a constant injection distance and hole to hole spacing. Yoshisaburo et al [12], Jalal et al [13] and Assim et al [14] clarified experimentally and numerically the heat transfer characteristics with multiple jets impingement.…”