Numerical modeling of heat transfer through the air interlayer considering the surface radiation

7th International Symposium Actual Problems of Computational Simulation in Civil Engineering

土木建筑工程;计算机科学

Umnyakova, N.P.^1

Research Institute of Building Physics, Russian Academy Architecture and Civil Engineering Sciences, Lokomotivny pr., 21, Moscow

127238, Russia^1

关键词: Air interlayers;    Design method;    Heat exchange;    Model of heat transfers;    National standard;    Surface radiation;    Thermal conductivity coefficient;    Thermal designs;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/456/1/012096/pdf
DOI  :  10.1088/1757-899X/456/1/012096

来源: IOP

【 摘 要 】

Current numerical models of facade's cladding do not account for ventilated air cavity heat resistance. The major problem in assigning its properties is the complexity of the air thermal conductivity coefficient calculation inside a ventilated air cavity. National standards and building codes provide design methods for calculating thermal resistance values for non-ventilated air layers depending on their thickness and location in the structure. The procedure of ventilated air cavity thermal design is not correct when its thermal conductivity coefficient is used as for a non-ventilated interlayer. In order to overcome the lack in the adequate design method, an approach utilizing both the finite element and analytical solutions of the heat exchange equation has been proposed in the present paper. In doing so, the formula derived for calculating the equivalent value of the air thermal conductivity in a ventilated air layer takes into account the heat exchange by radiation as a design value.