Effects of Rib Arrangements on Pressure Drop and Heat Transfer in a Rib-Roughened Channel With a Sharp 180 deg Turn

Abstract

The objective of this study was to investigate, through experiments, the combined effects of a sharp 180 deg turn and rib patterns on the pressure drop performance and distributions of the local heat transfer coefficient in an entire two-pass rib-roughened channel with a 180 deg turn. The rib pitch-to-equivalent diameter ratio P/de was 1.0, the rib-height-to-equivalent diameter ratio e/de was 0.09, and the rib angle relative to the main flow direction was varied from 30 ∼ 90 deg with an interval of 15 deg. Experiments were conducted for Reynolds numbers in the range 4000 ∼ 30,000. It was disclosed that, due to the interactions between the bend-induced secondary flow and the rib-induced secondary flow, the combination of rib patterns in the channel before and after the turn causes considerable differences in the pressure drop and heat transfer performance of the entire channel.

Thermal performance assessment of turbulent channel flows over different shaped ribs

“…The best value of the e/H ratio found to lie between 0.083 and 0.125 was reported. Mochizuki et al [8] studied the effect of rib arrangements on heat transfer in a rib-roughened channel with uniformly heating the four walls. Ribs were placed at 60°with e/H = 0.09 and the rib pitch ratio of 1.…”

“…Liquid crystal thermography technique was used for determining local temperature field. Different P/e ratios of 6,8,9,10,12,14 and 16 with only a single e/D ratio of 0.1 were introduced. They found that the heat transfer is highest at (P/e) ratios of 9 and 12.…”

Heat Transfer Enhancement by Detached S-Ribs for Twin-Pass Parallelogram Channel

“…The two stainless steel heating foils, (7) and (8), are sandwiched between the two pairs of copper plates (9) that connect with the electrical cables for feeding the adjustable heater powers to the test channel. The two pairs of copper plates (9) are embedded in the base plate (10). For electrical and thermal insulations, the channel base (10) and top (11) plates, the constituent channel walls (12)- (14) and the central divider are all made of Teflon.…”

Experimental Investigation of Heat Transfer in Two-Pass Coolant Passages With Ribs and Film Cooling Hole Ejection

“…Heat transfer characteristics have been reported in 45deg rib arrangement in literature. Several references describe area averaged results, performed mainly with thermocouples (Mochizuki et al [1] and Han et al [2]). Correlations presented in Han et al [3] and Han et al [4], have been built in single pass channel for several Re numbers and geometrical characteristics.…”