A Fundamental Study on the Control of Heat and Moisture States in Enclosed Environments

Part 1 The State Transfer Equations with Anisotropic Diffusion Effects

Abstract

The thermal and moisture states of the environment in enclosed spaces, such as the reefer hold of a refrigerated cargo ship or the air-conditioned living spaces, are manipulated by a forced circulation of air with controlled temperatures. The natural tendency to form thermal layers and heat pockets in the absence of properly balanced heat and humidity distributions in the air circulation, could make the living spaces uncomfortable and damage the refrigerated cargo. This makes it necessary to investigate and establish the various factors that govern this situation, through a detailed analysis of the problem.
This paper makes a precise numerical investigation of the thermal and humid environments in an anisotropic turbulent air flow subjected to gravitational effects, by including the diffusion terms with buoyancy effects also, in the momentum, heat and humidity transport equations. The air flow velocity, temperature and humidity distributions are experimentally measured in a thermally insulated box chamber, in which moist hot air blows and spontaneous evaporation from water pans kept on the floor, were employed to control the temperature and humidity distributions. Numerical and experimental results are compared with each other to justify the validity of the present theoretical formulation of the problem of turbulent heat and moisture transfer with buoyancy effects.