HEAT TRANSFER ENHANCEMENT IN A CHANNEL WITH INCLINED BAFFLES UNDER PULSATING FLOW: A CFD STUDY

This study numerically investigated hydraulic and thermal performance in a channel with inclined baffles under pulsating flow conditions. The baffles were placed in a staggered arrangement. The governing equations were discretized with the finite volume method (FVM), and the pressure-velocity coupling was handled by the SIMPLE algorithm. The Strouhal number (St: 0.5, 1, 2, 3, and 4), pulsation amplitude (A: 0.2, 0.5, and 0.8), and Reynolds number (200 = Re = 1000) were changed. The top and bottom surfaces of the channel were kept at T-w = 350 K, and thermal improvement and friction factor were calculated for a pulsating cycle. The results were given in terms of thermal enhancement (.), relative friction factor (f(rel)), and performance evaluation criteria (PEC). The flow and temperature contours were presented to determine the impacts of the pulsation frequency, the pulsation amplitude, and the Reynolds number. The results showed that the pulsation amplitude and the pulsation frequency contributed remarkably to thermal enhancement with increasing Reynolds numbers, while the heat transfer improved significantly depending on pulsation parameters together with a slight rise in friction factor. The highest thermal enhancement achieved was about 1.47 at Re = 1000, A = 0.8, and St = 4. The highest PEC obtained was approximately 1.12 at Re = 1000, A = 0.2, and St = 4.