The effect of trapezoidal baffles on heat and flow characteristics of a cross-corrugated triangular duct

The cross-corrugated triangular duct is a common flow channel in plate heat exchangers. To further improve the heat transfer in the cross-corrugated triangular duct, trapezoidal baffles were inserted in the flow channel in this study. The apex angle and baffle position on heat and flow characteristics of the flow channel are investigated. The flow fields, velocity contours, and temperature contours were obtained through calculation. Numerical results of friction factor (f), Nusselt number (Nu), and Performance Evaluation Criterion (PEC) for various channel structures were analyzed. The variations of apex angle and baffle position make the field more complex in the flow channel than that of without baffles. For various apex angles, the f of flow channels with an apex angle of 60° or 90° are close in value, higher than that of 120°. The same trend is found for Nu. When the baffles are in the center of the upper half of the channel, the flow duct owns the highest f, Nu, and PEC values. When the Reynolds number is less than 1000, the PEC value for the flow channel with a particular baffle position at the apex angle of 120° may be lower than that of without baffles.