A Study on the Thermophysical Properties of a Soil

The effect of water content on the apparent thermal diffusivity of a soil has been investigated in relation to time and position in the direction of heat flux. To evaluate the apparent thermal diffusivity the method of minimizing the sum of squares based on a forward-difference equation was used. The sample used for experiments was a sand whose mean grain size was 208 μm and mean dry bulk density about 1360 kg/m³. The measurements were conducted over a range of water content ratios φ (percent pore volume filled with water) from 0 to 93.9 percent and temperatures from 20 to 40°C. The result shows that the overall apparent thermal diffusivity in the case of φ = 9.6 percent and the local apparent thermal diffusivity change with time.