Гидродинамика

DETERMINATION OF THE MOTION OF A FLUID FOR ANY CONDI ­ TION GIVEN ON A STREAM-LINE This note by Prof. Joukovsky is an extension of t h e method of t h e directing and generating sets to the ease of motion of a f l u i d when the velocity along the stream-line on the boundary d o e s not remain constant, as has been assumed in Prof. Joukovsky's p r e c e ­ ding work, but is dependent on its direction. Prof. Joukovsky cons i ­ ders the following two cases'. 1. Motion of a heavy unbounded fluid when in the downco - ming flow there is arranged a vertical channel in which a c e r t a i n constant pressure is maintained (e. g. that of air), defined by t h e condition that the fluid cannot enter the channel and t he a i r cannot escape from it. There is determined t he shape of t h e contour of the current (equations 13) along which t he f l u i d approaches the vertical walls of the channel, and the d imens i ons of the channel which for the conditions imposed are proportional to the square of velocity. 2. Motion of a fluid when within the channel there is a r e ­ gion occupied by a stationary bubble of air, on the surface o f which are acting capillary tensile forces. This last problem g i v e s also the answer to the problem of the form of the bubbl e of air rising in a channel filled with a fluid at rest.