Numerical analysis of heat transfer of a nanofluid counter-flow heat exchanger

Experimental Study on Convective Heat Transfer and Pressure Drop Characteristics of an Alternating Cross-Section Flattened Tube with Different Twist Angle

“…The passive technique is generally preferred because this method does not need any external energy to enhance heat transfer. The objective can be achieved by inserting twinned coil/twisted tape into the tube [2][3][4][5][6], adding nanoparticles to the base fluid [7][8][9][10][11], and modifying the tube structure of the heat exchanger, such as with a corrugated tube [12][13][14], a micro-fin tube [15][16], a flattened tube [17][18], a twisted flattened tube [19], or a twisted oval tube [20][21]. These reports concluded that modifying the tube shape to enhance the heat transfer of the internal flow was an attractive approach.…”