将式(3-1)对时间求一阶和二阶导数,可得任意流体 质点的速度和加速度为: (a,b,c,) aaa00 v(a.、b,C. (3-2) w(a, b,c, t) u at at a(a, b,c,t) av a a,(a,b,c, t) (3-3) at at a(a,b,c, t 2021/2202021/2/20 5 将式（3-1）对时间求一阶和二阶导数，可得任意流体 质点的速度和加速度为： (3-2) (3-3) u(a,b,c,t) t x u =   = v(a,b,c,t) t y v =   = w(a,b,c,t) t z w =   = ( , , , ) 2 2 a a b c t t x t u ax = x   =   = ( , , , ) 2 2 a a b c t t y t v ay = y   =   = ( , , , ) 2 2 a a b c t t z t w az = z   =   =