کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
787380 | 1466468 | 2009 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Flow patterns and heat and mass transfer coefficients of low Reynolds number falling film flows on vertical plates: Effects of a wire screen and an additive Flow patterns and heat and mass transfer coefficients of low Reynolds number falling film flows on vertical plates: Effects of a wire screen and an additive](/preview/png/787380.png)
The effects of the surface geometry and of a surfactant on the characteristics of LiBr–water solution falling films are experimentally investigated. Two different surfaces (flat copper plate and the same copper plate covered with a copper wire screen) are tested with four fluids (pure water and 50% lithium bromide–water solution with or without 100 ppm of 2-ethyl-1-hexanol) for Reynolds numbers from 40 to 110. Flow patterns and heat and mass transfer coefficients are discussed. Marangoni convection was observed in water-cooled LiBr–water flows resulting in significant heat and mass transfer enhancement. 2-ethyl-1-hexanol enhances heat and mass transfer in LiBr–water flows by more than a factor of two. 2-ethyl-1-hexanol in water makes copper surface strongly hydrophobic. The wire screen promotes absorption process in adiabatic conditions but hinders the process in non-adiabatic conditions by reducing the Marangoni convection induced by 2-ethyl-1-hexanol. The experimental heat and mass transfer coefficients are presented in dimensionless forms.
Journal: International Journal of Refrigeration - Volume 32, Issue 1, January 2009, Pages 138–149