Experimental investigations of pressure loss and heat transfer in a 180° bend of a ribbed two-pass internal cooling channel with engine-similar cross-sections

In the present study, the pressure loss and heat transfer of a two-pass internal cooling channel with engine-similar cross-sections were investigated experimentally. This channel consisted of a trapezoidal leading edge pass, a sharp 180 degrees bend, and a nearly rectangular outlet pass. The investigations focused on the influence of tip-to-web distance and rib configuration on pressure loss and heat transfer. The channel was equipped with skewed ribs (alpha = 45 degrees, P/e = 10, e/d(h) = 0.1) in an inline and a staggered configuration. The dimensionless tip-to-web distance W(el)/d(S) was varied from 0.6 to 1.2. The investigated Reynolds number ranged from 15 000 up to 100 000. The experimental results showed a strong increase in pressure loss with decreasing tip-to-web distance, while heat transfer was only slightly increasing. Both rib configurations showed nearly the same heat transfer enhancement in the bend region.