Flow over a cylinder

Aim - To Simulate the flow over a cylinder for the conditions shown in the video.

Objectives -

1. Calculate the baseline case Reynolds number.

2. Increase the Reynolds number by a factor of 20%, 40%, and 100% then run the transient flow simulation.

3. Create animations for pressure-velocity for all the three Reynolds number.

Theory

Geometrical Aspect

Calculation of baseline Reynold's number

Re = rho*U_inlet*D/mu

D = cylinder diameter = 40mm = 0.04m

mu = dynamic viscosity = 18.37*10^-6 Pa-sec

rho = density = 1.225 kg/m^3

U_inlet = 10 m/s

Re = 26673.92 = 26674

20% increase in baseline Re = 32008

20% increase in baseline Re = 37343

20% increase in baseline Re = 53348

Dimensions of computational Domain (same for all)

X-max = 0.22

X-min = -0.22

Y-max = 0.14

Y-min = -0.14

Z-max = 0.17

Z-min = 0.17

Calculation of Flow through time

for 20% increase = 0.036

end time = 0.073

for 40% increase = 0.0314

end time = 0.062

for 100% increase = 0.022

end time = 0.044

For Baseline simulation

For 20% increase

velocity

pressure

For 40% increase

velocity

pressure

For 100% increase

velocity

pressure

Observations

1. As Re increases, velocity increases and flow through time decreases.

2. No significant changes in the pressure plots.

3. Velocity profiles in 20 and 40 are almost same but there is a significant change in the 100% increase.

Conclusion

The objectives of this project was met and the results explained and plots and animation shown.

The animation files are attached below ...