Enhanced Hydrodynamic Performance of Fluid Flow in a Rectangular Channel Using Baffles with Gaps

Abstract

In the present analysis, a new geometry of obstacles is considered in order to demonstrate its importance in improving the thermal-hydrodynamic performance of hydrogen fluid within a 2D, rectangular section channel subject to a constant surface temperature condition along its hot top wall. The new obstacle has a variable-position square-shaped gap (called: perforated obstacle), to reduce its resistance to the fluid flow, to decrease the skin friction, in order to determine the optimum configuration for a high heat transfer. This gap has three different positions (dg) in the (h) height baffle section, i.e., dg = 0.25h, 0.5h and 0.75h reported, respectively, as A, B and C types. The governing equations among the fluid and solid sections are determined and solved via the finite volume method (FVM). The obtained results are presented for Re = 5 × 103-2 × 104. The thermal improvement factors of the channel containing the perforated baffle appear to be greater than unity for all dg gap positions situated between 1.143 and 4.236, and dependent on the values of dg and Re, which suggest a better thermo-hydrodynamic performance compared to that obtained with a smooth channel. It is found that the thermo-hydrodynamic improvement value in case C of a 0.75h perforated baffle decreases by 2.747% compared to the case of a simple obstacle with no gap, at Re = 2 × 104. However, the value of this same factor increases by 5.901% and 2.794% when the value of dg is equal to 0.25h and 0.5h, respectively, for this same great value of the Reynolds number. Therefore, the perforated baffle model with a small gap position distance (dg = 0.25h) can be selected as the best geometric model for a good thermal improvement with minimal frictions inside the channel. The subject is relevant and important for industrial applications.

2D Numerical Study of Heat Transfer Enhancement Using Fish-Tail Locomotion Vortex Generators

“…The results showed that the use of SiO2-EG at a volume fraction of 6% and of 800 results in a higher average Nusselt number of about 50% compared to the case of using =100. Other interesting analysis of the effect of different techniques with and without nanofluids on enhancing heat transfer can be found in references [24][25][26]. Many studies investigated the effect of hydrodynamics on fish locomotion.…”