AN EXPERIMENTAL STUDY OF FRICTION FACTOR IN THE TRANSITION REGION FOR SINGLE PHASE FLOW IN MINI- AND MICRO-TUBES

A systematic and accurate experimental investigation of friction factor in the transition region for single phase flow in mini- and micro-tubes has been performed for eight stainless steel tubes with diameters ranging from 2083 mu m to 667 mu m. The pressure drop measurements were carefully performed by paying particular attention to the sensitivity of the pressure-sensing diaphragms used in the pressure transducer. Experimental results indicated that the start and end of the transition region was influenced by varying the tube diameter. The friction factor profile was not significantly affected for the tube diameters between 2083 mu m and 1372 mu m. However, the influence of the tube diameter on the friction factor profile became noticeable as the diameter decreased from 1372 mu m to 667 mu m.