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Equations of motion for fluids

 

The motion of fluids and gases are described with the Navier-Stokes equation  and the equation of continuity   [11, ]:
  eqnarray138
These two equations describe the motion of fluids in both two- and three-dimensional systems.

tex2html_wrap_inline4305 is the velocity field. tex2html_wrap_inline4307 denotes the derivative of a quantity when you follow the flow (as opposed to tex2html_wrap_inline4309 ) and can be expanded to tex2html_wrap_inline4311. tex2html_wrap_inline4313 is the density of the fluid. p is the pressure. tex2html_wrap_inline4317 is the kinematic viscosity and tex2html_wrap_inline4319 is the second viscosity. The viscosity of a fluid can under most circumstances, including the experiments presented in this thesis, be considered constant. F represents external forces such as gravity and the Coriolis-force.





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