Heat transfer coefficient for constant flow solar collector/storage systems

An earlier expression for the heat transfer coefficient between the heated surface and the flowing fluid used in the investigation of the performance of a few collector/storage systems leads to results which are physically impractical. In this communication we derive the correct expression for the heat transfer coefficient in terms of the parameters of the tube, i.e. its length and circumference. The effect of the modified form of the heat transfer coefficient on the performance of a typical system, namely a ground collector system, has been studied in detail.