【单选题】7 / 12

黏性不可压缩均质流体的运动方程是

  1. ρdvdt=ρFgradp+μ2v\rho\frac{d\boldsymbol{v}}{dt}=\rho\boldsymbol{F}-\operatorname{grad}p+\mu\nabla^2\boldsymbol{v}

    正确
  2. ρdvdt=ρFgradp\rho\frac{d\boldsymbol{v}}{dt}=\rho\boldsymbol{F}-\operatorname{grad}p

  3. ρdvdt=ρF+divP\rho\frac{d\boldsymbol{v}}{dt}=\rho\boldsymbol{F}+\operatorname{div}\boldsymbol{P}

  4. ρdvdt=ρFgradp+μ2v+μ3graddivv\rho\frac{d\boldsymbol{v}}{dt}=\rho\boldsymbol{F}-\operatorname{grad}p+\mu\nabla^2\boldsymbol{v}+\frac{\mu}{3}\operatorname{grad}\operatorname{div}\boldsymbol{v}

参考答案

A

参考解析

divv=0\operatorname{div}\boldsymbol{v}=0 时 N-S 方程简化为 ρdvdt=ρFgradp+μ2v\rho\frac{d\boldsymbol{v}}{dt}=\rho\boldsymbol{F}-\operatorname{grad}p+\mu\nabla^2\boldsymbol{v}K352K3-52)。