Experimental study of heat transfer characteristics in a curved path with multi-hole impingement

Ice formation on airplane has a great influence on the plane's working condition. Therefore the effective anti-icing on some internal assemblies needs to be conducted when the temperature is low. This paper studies experimentally on the heat transfer in a curved path within the cowl. Experiments are carried out by using a transient thermochromic liquid crystal technique. The dimensionless tangential distance (L/H, where L is the tangential distance, H is the height of the path), the dimensionless axial distance (x/X, where x is the arc distance from the leading edge hole to the side impingement hole, X is the arc distance from the edge of the curved path to the leading edge impingement hole) as well as the pitch ratio (D/d,where D is the leading edge hole, d is the diameter of the side impingement hole) of the leading edge and side impingement holes are respectively investigated to study the heat transfer on the surface of curved path. Within the experimental range, the result shows that the Nusselt number at the impingement hole rises with the increase of the dimensionless axial distance x/X. The increasing dimensionless tangential distance L/H of side impingement holes leads to a higher Nusselt number both to peak value and tangential mean value. When the pitch ratio D/d increases, the Nusselt number at the leading edge of the hole goes up while it reduces at the side impact holes.