Flow over a cylinder

Aim: To Simulate the flow over a cylinder for given conditions

Objective: The following objectives are carried on a cylinder.

1. Calculate the Reynolds number for the baseline simulation.
2. Run a baseline simulation.
3. Run a transient flow simulation for an increasing reynolds number by a factor of 20%, 40%, 100% of the baseline reynolds number.
4. Create animations for pressure-velocity for all the three Reynolds number.

Considered Parameters & dimensions:

Cylinder diameter = 100 mm

Length = 200 mm

Base Velocity= 10 m/s

density of air= 1.225 kg/m3m3

dynamic viscosity= 1.81*10−510-5 (at 15° c)

Calculation:

Re = rho*V*D/mu

D = cylinder diameter

mu = dynamic viscosity

rho = density

at 10m/s

Reynold number=67680

Case 1: Increased Reynold's number by 20% (By increasing inlet velocity)

Velocity Simulation:

Video: https://youtu.be/OtjSAn7bCzI

Pressure Simulation:

Video: https://youtu.be/DN5LcvLBRzc

Case 2: Increased Reynold's number by 40% (By increasing inlet velocity)

Velocity Simulation:

Video: https://youtu.be/doOe5Cfmva0

Pressure Simulation:

Video: https://youtu.be/bulwqD5slcg

Case 3: Increased Reynold's number by 100% (By increasing inlet velocity)

Velocity Simulation:

Video: https://youtu.be/7ga3iBgF8Uk

Pressure Simulation:

Video: https://youtu.be/pLYTFPE1R0Y

Conclusion:

As the Velocity & Reynold's number increase, time required to become velocity profile & pressure steady decreases. At same time, the velocity plot at 20% and 40% exhibit slight unsteady plot whereas at 100% the flow is steady.