AN EFFECTIVE INSTALLATION OF TURBULENCE PROMOTERS FOR HEAT-TRANSFER AUGMENTATION IN A VERTICAL RIB-HEATED CHANNEL

Parameter studies including the channel spacing, convective heat flux, channel inlet velocity, turbulence-promoter location and height on heat transfer performance and pressure drop in a vertical rib-heated channel have been explored in detail. In addition, the rib/overall channel Nusselt numbers and the coefficient of channel pressure drop C(p) are correlated and presented in terms of relevant dimensionless parameters studied. The experimental results show that the installation of turbulence promoter on the opposite shrouding insulated wall in the vertical rib-heated channel can effectively enhance all the rib heat transfer performances in the channel and avoid hot spots occurring in the 'quasi-equilibrium' high-temperature regime. Taking both thermal and flow aspects into consideration simultaneously, Nu and C(p) increase hand in hand with increasing ratio of promoter height to channel spacing t/H. This tendency is consistent with the increased levels of flow disturbance, or turbulence mixing, promoted by the protruding ribs and the installed turbulence promoter.