کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
662380 | 1458185 | 2005 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Measuring and modeling vapor boundary layer growth during transient diffusion heat and moisture transfer in cellulose insulation Measuring and modeling vapor boundary layer growth during transient diffusion heat and moisture transfer in cellulose insulation](/preview/png/662380.png)
In this paper, an experimental test facility that permits continuous measurements of transient heat and moisture transfer in porous media is applied to study the vapor boundary layer in cellulose insulation. The experiment measures the relative humidity, temperature and moisture accumulation within the cellulose specimen with a fully developed flow of air at a controlled temperature and humidity provided above the surface. These experimental results are used to verify a mathematical model, which is used to develop an expression for moisture diffusivity (αm) that is analogous to thermal diffusivity, and takes into consideration moisture storage. The moisture diffusivity is used to calculate the vapor density in the boundary layer and the size of vapor boundary layer in cellulose insulation. It is found that the moisture storage effect has a very significant effect on the vapor boundary layer and cannot be ignored. For cellulose insulation, the size of the vapor boundary layer may be over predicted by a factor of ten when moisture storage is neglected.
Journal: International Journal of Heat and Mass Transfer - Volume 48, Issue 16, July 2005, Pages 3319–3330