1877 л ? 1826, Daniel Colladon, Charles Sturm, , 1687, 1490, : л... , , ...? r r p r v r r r r + g + v + (v, )v = - t r + div ( v ) = 0 t r v r r + + div v 3 r r v p r + g =- t / r + div v = 0 : rrr r r t v = v 0 + v v 0 = 0 v - r p = p 0 + p p p p 0 0 r =g 0 0 = 0 + r v t r v t r r p 0 p r =- - +g t 0 0 =- r p r +g r v =- r (p 0 + p) 0 + r +g r -g r v t =- r p 0 t (0 + ) t t r + div v = 0 r + div (0 + ) v = 0 r r + div (0 v + v) = 0 t r + 0 ...