Thursday, January 5, 2012

Flow around an egg

My first result: The flow around an egg with diameter 1 and length 1.5 m. I used a very non realistic kinematic viscosity (nu) for this simulation: 0.01 m2/s. The Reynolds number Re=d*u/nu = 1*10/0.01=1000. The kinematic viscosity of air is 15e-6 m2/s. With that kinematic viscosity Re would become ~7e+05. I used the icoFoam solver. At the more realistic higher Reynolds numbers an other solver has to be used.
Flow around an egg. p is the reduced flow pressure/rho.

The egg was modelled in Rhino, exported to a stl file. With the OpenFoam tool snappyHexMesh a mesh was created.

The next figure shows the flow at Re 7e5. At the back side a vortex is visible.

kinematic viscosity of air increased to 15e-6 m2/s, Re~7e5