The measurement of convection heat transfer characteristics in a supercritical carbon-dioxide gas tube by the use of an extended temperature oscillation method

Presented is an extended temperature oscillation model for the measurement of in-tube convection heat-transfer factor during the variation of fluid temperature in a small duct. The recommended method can be employed to measure the local convection heat-transfer factor of flows in various kinds of smooth-surface duct. An actual measurement was conducted of the supercritical CO₂ convection heat-transfer factor in a round stainless steel tube of 2 mm inner diameter under typical pressure and temperature conditions.