Investigation of effective thermal conductivities of powders

Memorandum presenting a simplified analysis to determine the effective thermal conductivity of a powder from the fraction of space occupied by the gas and conductivities of the solid and the gas which make up the powder. Tests were conducted to determine the conductivity of magnesium oxide powder in various gases at a range of temperatures. The effects of some of the factors neglected in the simplified analysis, such as bending of the heat-flow lines and the irregularity of the arrangement of the particles, were investigated and discussed.