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

在封闭的空间中，如冷藏货船的冷藏舱或有空调的起居室，环境的热和湿度状态是通过控制温度的强制空气循环来操纵的。在空气循环中没有适当平衡的热量和湿度分布时，自然会形成热层和热袋，可能会使居住空间不舒服，并损坏冷藏货物。因此有必要通过对问题的详细分析来研究和确定控制这种情况的各种因素。本研究通过在动量、热量和湿度输运方程中加入具有浮力效应的扩散项，对受重力影响的各向异性湍流气流中的热环境和湿环境进行了精确的数值研究。基于Law公式，给出了雷诺应力、湍流热通量和湿通量的近似表达式。这些表达式是如此明确，以至于扩散项是可微的，并且引力影响在动量和热输运方程中直接可见。实验测量了隔热箱式房间内的气流速度、温度和湿度分布，采用湿热吹风和地板上的水锅自发蒸发来控制温度和湿度的分布。将数值计算结果与实验结果进行了比较，验证了考虑浮力效应的湍流热湿传递问题的理论表述。

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 study 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 approximate expressions of Reynolds stresses turbulent heat flux and humid flux based on the Launder's formula are proposed. These expressions are so explicit that the diffusion terms are differentiable and the gravitational influence becomes directly visible in the momentum and heat 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 present theoretical formulation of the problem of turbulent heat and moisture transfer with buoyancy effects.