Thermal design of an orthotropic flat fin in fin-and-tube heat exchangers operating in dry and wet environments

A semi-analytical method was described to determine the thermal performance of fin-and-tube heat exchangers with orthotropic fin materials and wet surfaces. The effect of the orthotropic thermal conductivity was investigated over a range of design parameters for both wet and dry fins, and design optimization was carried out using a generalized Newton–Raphson method. The optimized designs were analyzed to gain insight into the relative importance of the different parameters under varying conditions, and a set of curves was determined to provide design optimization guidelines.