Experimental Study on the Effect of Spiral Spring Inserts in a Circular Tube in Case of Forced Convection Heat Transfer.

Document Type : Research Studies

Authors

1 Mechanical Power Engineering Department., Faculty of Engineering., El-Mansoura University., El-Mansoura., Egypt.

2 Lecturer at Mechanical Power Engineering Department., Faculty of Engineering., El-Mansoura University., El-Mansoura., Egypt.

Abstract

Results are presented from experimental investigations of convective heat transfer and friction loss in a 13.5 mm Inside diameter copper tube in case of air flow. This tube is fitted with helical-wire- coil inserts of varying diameter (DC) ranges between 1.4 and 9.4 mm constant pitch to diameter ratio (P/d=3) and constant wire diameter (d = 1.4 mm). The outer surface of the test tube is heated by a little superheated steam (2-3 °C) at one atmosphere. During this work, Reynolds number varied between 60 and 4000 and Prandtle number was about 0.7. The heat transfer enhancement for the tested tube with internal coils was higher than that of the bare one by value ranges between 25% and 45%. The pressure loss results show a quantite-vely increase in the pumping power. 

Main Subjects