上降充通大￥ 3.1流体动力学的两个研究途径 Shanghai Jiao Tong University 系统(system:由确定的流体质点组成的流体团。 物质体积Material Volume):由 G(x,y,z,t)dv 系统的流体团构成的体积(a ) volume that contains the same V() fluid as it moves and deforms following the motion of the fluid.) G(x,y,z,1) 物质表面Material Surface):物 质体积的封闭表面(enclosing surface of a material volume;by definition no fluid particles can cross it.)Shanghai Jiao Tong University 3.1 流体动力学的两个研究途径 系统(system)：由确定的流体质点组成的流体团。 物质体积(Material Volume): 由 系统的流体团构成的体积(a volume that contains the same fluid as it moves and deforms following the motion of the fluid.) 物质表面(Material Surface): 物 质体积的封闭表面(enclosing surface of a material volume; by definition no fluid particles can cross it.)