The present paper deals with the measurement of the apparent thermal conductivity of the sand layer packed in a flat square box using the heat flow meter method. The grain size of sand is in the range of 1.4 to 1.7mm in diameter. The bulk density and the poroslty of the dry sand layers were 1520±20kg·m-3 and 0.42±0.01, respectively. The measurement was carried out repeatedly at average temperatures of the sand layer ranging from 280 to 350K, and water saturation of the sand layer, S, was in the range of 0 to 1. When the temperature difference of the sand layer was about 10K, the thermal conductivity increased with increasing the temperature and water content. The thermal conductivity of the dry sand and water saturated sand layers were 0.3 and 2.4W·m-1·K-1, respectively.
A round-robin thermal diffusivity measurement by the laser flash method(LF) was conducted to examine applicability to rocket nozzle materials. The result of the test showed that the measure values for graphite and CFRP were not scattered depending on the measurement systems, but that for 3-dimensional carbon matrix woven carbon fiber reinforced composites(3D-C/C) the values took with larger scatter. Based on this test result, a numerical simulation corresponding to the LF method for such kind of materials was carrried out by a finite element method. Through the simulation, we investigated the fundamental problem in applying the LF analysis for such materials, and obtained important infomation to improve the measurement method.