Experimental and Numerical Studies of Natural Insulation Materials

Abstract

To find 100% natural, unrefined materials in place of synthetic materials for insulation industry, laboratory experiment and numerical modeling have been carried out. The materials studied include human hair, tree leaves, cotton and sawdust. The experiments have been done in a cylindrical vessel with a hollow center. Time history of temperature at the inside surface has been recorded in the laboratory. Accordingly, thermal diffusivity for the four different materials has been obtained. It is found that cotton has the maximum value of thermal diffusivity, with leaves ranking the second, and sawdust following as the third. On the assumption that the natural material is uniform and isotropic, in which heat transfer takes the form of conduction, the numerical modeling procedure has been developed. It is based on the differential energy equation in cylindrical coordinates. Numerically, the finite difference approach has been used. The results include thermal diffusivities for the four natural materials and the temperature distribution in both time and space. The numerical results agree well with experiment.