Flow over a cylinder

Aim : To simulate the flow over a cylinder for the conditions given and to calculate the Reynolds number. Then to increase the Reynolds number by a factor of 20%, 40%, and 100% then to run the transient flow simulation.

Solution:

A cylinder with a diameter of 40mm and length 50mm is sketched and extruded. Then a flow simulation is run with a time dependent study with analysis time from 0.1 and 0.01 seconds. The velocity is set to 10m/s and Reynold's number is calculated to be 27071.82( Using Re= density*velocity*diameter/dynamic viscosity).

A cut plot is made in the middle of the cylinder and it is shown.

An animation wizard is created for an interval of 10 seconds to see the velocity and pressure behaviour.

The same procedure is repeated for the different Reynold's numbers.

When Re is increased by 20% it becomes 32486.2 and accordingly velocity is found to be 12m/s.

Similarly, the same procedure is repeated for other Reynold's numbers and velocities are calculated.

Velocity-10m/s (Re default)

Velocity animation : https://youtu.be/A20SOZii-qU

Pressure animation : https://youtu.be/pDaLX6Hhf1M

Velocity-12m/s (Re increased by 20%)

Velocity animation : https://youtu.be/bHZ7fG4ckZk

Pressure animation : https://youtu.be/zdVhci47MtM

Velocity-14m/s (Re increased by 40%)

Velocity animation : https://youtu.be/n7NnvG3Ns6E

Pressure animation : https://youtu.be/V2BYd6eLIv8

Velocity-20m/s(Re increased by 100%)

Velocity animation: https://youtu.be/YPUZGTg9LjM

Pressure animation : https://youtu.be/MckVgkBjCMI

Result : The flow simulation and animations were made for the given criteria and increased Reynold's number. We can clearly see that the pressure is the highest closest to the cylinder.