Interdisciplinary Applied Mathematics

Скачать в pdf «Interdisciplinary Applied Mathematics»


dus


—> 0 as av —► 0,


dn


and equation (2.20b) becomes obsolete, since the Euler equations require only the no-penetration boundary condition in this limit. 2


TABLE 2.1. Thermal and tangential momentum accommodation coefficients for typical gases and surfaces (Seidl and Steinheil, 1974; Lord, 1976).


Gas


Surface


(Jj1


(J v


Air


Al


0.87-0.97


0.87-0.97


He


Al


0.073


Air


Iron


0.87-0.96


0.87-0.93


H2


Iron


0.31-0.55


Air


Bronze


0.88-0.95

о


<


2


H


____£______________________________________________


1.2


1


. I .


I


; i ■i» 2i ■


0.8


) 1 I I I i it )


CD


О


0W1


) )


) ■)


0.4


) )


0.2


) )


— , , , , | , , , , | , , , , | , , , , | , , , , —


0


— , , , , i , , , , i , , , , i , , , , i , , , , —

0    0.1    0.2    0.3    0.4    0.5


Ko


0    0.1    0.2    0.3    0.4    0.5


Ko


FIGURE 2.3. Tangential momentum accommodation coefficient av (TMAC) versus Knudsen number obtained from mass flowrate measurements for argon (left) and for nitrogen (right). (Courtesy of K. Breuer.)

Скачать в pdf «Interdisciplinary Applied Mathematics»

Метки