EXPERIMENTAL INVESTIGATION OF CONVECTIVE HEAT TRANSFER OF SUPERCRITICAL PRESSURE HYDROCARBON FUEL IN A ROTATING CENTRIFUGAL CHANNEL
Experimental investigation of the heat transfer of supercritical pressure n-decane flowing through a 2-mm-diameter and 200-mm-long pipe under varying rotational speed, mass flow rate, inlet temperature, and heat flux is presented. The wall temperature was measured at four positions around the periphery of the pipe at each of the five selected cross-sections along the pipe length. Maximum convective heat transfer was observed along the trailing edge of the centrifugal section while its corresponding minimum was observed along the leading edge. Heat
transfers along the two sides of the channel were observed to be identical. The section average convective heat transfer coefficient was found to demonstrate an increase with increase in the rotational speed, and its value corresponding to 1500 rpm was observed to lie in the range of approximately 2−2.5 times that observed under static condition. The strong effect of buoyancy force caused by centrifugal force and flow deceleration caused by pressure drop tended to limit
the deterioration of the local heat transfer. This paper presents an expression for a dimensionless criterion concerning the buoyancy force generated under rotating conditions and proposes a new local Nusselt number correlation apropos the heat transfer of n-decane flowing through a rotating centrifugal section under operating conditions of supercritical pressure.