The experiments were performed to examine the influence of using A-CR inserts on heat transfer and fluid flow characteristics of air flow in a tube. The experiments were carried out in an open-loop experimental facility as shown in Fig. 2. The loop consisted of a three hp blower, orifice meter to measure the mass flow rate, and the heat transfer test section. The heat transfer test section was heated by continually winding flexible electrical wire provided a uniform heat flux boundary condition. The electrical output power was controlled by a variac transformer to obtain a constant heat flux along the entire length of the test section and by keeping the current less than 3 amps. The outer surface of the test tube was well insulated to minimize convective heat loss to surroundings, and necessary precautions were taken to prevent leakages from the system. The inner and outer temperatures of the bulk air were measured at certain points with a multi-channel temperature measurement unit in conjunction with the type-T thermocouples. Fifteen thermocouples were tapped on the local wall of the tube (embedded in V-groove tube surfaces) and the thermocouples were placed round the tube to measure the circumferential temperature variation, which was found to be negligible. The mean local wall temperature was determined by means of calculations based on the reading of the type-T thermocouples.