On the Emissivity of a Gas which Contains Particles

Abstract

The author has found a new theoretical way of calculating the emissivity of a gas which contains particles. The emissivity of a gas, which contains a group of particles, is calculated by the following equations. εG_a is the emissivity by the same gas when it does not contain particles. εG_a=1-e^<-(K_GLL)> εG_a'=1-e^<-(K_GLL)>'(K_GLL)'=(K_GLL) (1+γ) [chemical formula] where L is the thickness of gas layer. The particles are assumed to distribute uniformly and constitute spheres of equal diameter. A_P is the area of a sphere surface. Side planes of an imaginary cube, which corresponds to a sphere, are perfectly black and A_B is the area of a cube surface. As ΔL is the length of edge of a cube, A_B is 6 (ΔL)². (K_GΔLΔL) and (K_GLL) are factors corresponding to the thickness of gas layers ΔL and L for εG_a of a gas as in above equations. These are given by Hottel and others for non-luminous gases. The experiments by the author show that the results agree well with his theoretical analysis. The experimental results by Sherman, being analysed by author's methed, show no contradiction. The experimental formula by Lindmark and Wohlenberg are expressed as special cases of author's theory. For a gas, which contains two or more groups of particles calculation can be made by repeating the above method. From the calculation it is revealed that an emissivity of a gas, which contains a group of particles, is greater than that of a gas alone. In this case the temperature of particles is assumed to be not lower than that of a gas. The increment of emissivity is expressed by the above equations.