HE THEORY OF THIN BODIES
S. K. Betyaev UDC 532.527 It is shown that, in accordance with the law of plane sections representing the basis of the theory of thin bodies, two analogies are true: a nonstationary analogy and a stationary one. Within the framework of the stationary analogy, a new-type expansion reducing a three-dimensional problem to a stationary two-dimensional one is introduced. The asymptotic conditions of validity of the stationary and nonstationary analogies were determined and the boundary-layer conceptions for both cases were compared. Solutions of the internal and external problems on a two-dimensional flow in a narrow zone were obtained in the closed form. An asymptotically correct mathematical model of a flow in a film is proposed. The stationary and nonstationary analogies for a swirling flow around a body and a flow around a rotating body were determined. Prof. N. E. Zhukovskii Central Aerodynamics Institute, 1 Zhukovskii Str., Zhukovskii, Moscow Obl., 140181, Russia; email: betyaevs@gmail.comanslated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 5, pp. 45-54, September-October, 2007. Original article submitted February 22, 2006.