Laminar flow, Re 250
Lower Reynolds number. Note the larger wake and the pronounced vortex street.
Velocity vectors
Temperature
Cylinder wall heated, cold flow
Vorticity
Result is postprocessed in VisIt using “vorticity = 0.5*dot({0,0,1},curl(nvelocity))”
Other details
Detail of the velocity vectors immediately behind the cylinder
Turbulent flow, Re 20,000
Higher Reynolds number, the viscosity lowered to 0.0001. Note the smaller wake and the less pronounced vortex street.
Velocity vectors
Temperature
Cylinder wall heated, cold flow
Vorticity
Result is postprocessed in VisIt using “vorticity = 0.5*dot({0,0,1},curl(nvelocity))”
Other details
The velocity magnitude
Pressure
In the stagnation point it reads 0.5 Pa
Turbulent kinetic energy k
Turbulent dissipation rate epsilon
Turbulent kinetic energy k and the turbulent dissipation rate epsilon combined result in the effective viscosity
The turbulent kinetic energy k is a measure of the turbulent fluctuations and they can be related to the velocity magnitude giving the turbulent intensity i
Result is postprocessed in VisIt using “intensity = sqrt(0.66666) / (max(,0.001)) * 100.0”
From the turbulent kinetic energy k and the turbulent dissipation rate epsilon the turbulent length scale l can be derived
Result is postprocessed in VisIt using “length_scale = 0.09^0.75 * ^1.5 / ”