Experimental measurements of thermal conductivity of hydrocarbon fuels by a steady and kinetic method

Abstract

A steady and kinematic thermal conductivity measurement method is proposed for the round tube flow in laminar regime under constant heat flux condition. And this method is based on the fact that heat transfer coefficient depends only on thermal conductivity λ and inner diameter and is independent of V, ρ, and Cp in laminar flow with fully developed temperature and velocity profile. This independence results from the fact that the energy transport is purely molecular conduction problem under these conditions. The uncertainty of the measurement is within ± 3.0 % (coverage factor k = 2) according to the uncertainty analysis. For validation, the thermal conductivity of toluene and ethanol was measured at the temperature range of (288–372) K. And the validation tests show that the relative deviation of measured thermal conductivity from standard data is within an error band of 2 %. Using this method, thermal conductivity of a typical hydrocarbon aviation fuel RP-3 was measured.