ANALYTICAL SOLUTION OF THE PROBLEM ON THERMAL SLIP OF 
SECOND ORDER FOR MOLECULAR GASES

V. N. Popov

UDC 533.72

Results obtained using exact analytical methods in the 
problem on thermal slip of second order for molecular gases with allowance 
for the rotational degrees of freedom of molecules have been presented. 
Numerical calculations of the thermal-slip coefficient for a number 
of molecular gases have been carried out. The dependence of the velocity 
of thermal slip of second order of a molecular gas on the Prandtl 
number has been shown. The found value of the coefficient of thermal 
slip of second order theoretically confirms the existence of negative 
(in the direction of the temperature gradient) thermophoresis for 
molecular gases.

M. V. Lomonosov Pomor'e State University, 4 Lomonosov Ave., 
Arkhangel'sk, 163002, Russia; email: popov.vasily@pomorsu.ru. 
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 3, pp. 
190-194, May-June, 2006. Original article submitted November 
10, 2004; revision submitted April 14, 2005.