Predicting the Thermal Conductivity of Foam Neoprene at Elevated Ambient Pressure

The purpose of this paper is to present a correlation for predicting the thermal conductivity of foam neoprene at varying ambient pressure. In a previous study, the authors used well-known upper and lower bounds to develop the form of a semi-empirical correlation for the thermal conductivity of foam neoprene as a function of increasing ambient pressure. The correlation was in terms of three constants, which were determined by performing a nonlinear regression on experimentally measured thermal conductivity values of foam neoprene insulation at varying ambient pressure. In this present paper, we show that the three correlation constants can, alternately, be determined by using values of the constituent thermal conductivities (e.g., air and rubber) and the effective thermal conductivity at one pressure point only (reference pressure). Values predicted using the correlation were compared with previously measured values of the effective thermal conductivity of foam neoprene insulation under increased ambient pressure, up to 1.18 MPa. It was found that there was a maximum difference of approximately 14% between the predicted and measured values. It was also found that the accuracy of the correlation did not depend strongly on the reference pressure used. It was therefore concluded that the effective thermal conductivity of foam neoprene, as a function of increasing ambient pressure, can be predicted if the constituent thermal conductivities are known (air and rubber), as well as the effective thermal conductivity at one reference pressure.