Flow over a cylinder

Aim of this study is to simulate flow over cylinder

The Reynolds number (Re) is an important dimensionless quantity in fluid mechanics used to help predict flow patterns in different fluid flow situations. At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers turbulence results from differences in the fluid's speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow (eddy currents). These eddy currents begin to churn the flow, using up energy in the process, which for liquids increases the chances of cavitation.

The Reynolds number is the ratio of inertial forces to viscous forces. The Reynolds number is a dimensionless number used to categorize the fluids systems in which the effect of viscosity is important in controlling the velocities or the flow pattern of a fluid.

`Re = (rho*V*D)/mu`

where ,

`rho` is density in kg/m^3

D is Diameter in m

`mu` = viscosity in Pa-s

Initial condition:

D=0.25m

L=0.5m

`rho`= 1.225 kg/m^3

`mu` = 1.802x10^-5 Pa-s

case-1 , Initially consider the velocity of 10m/s

Re = 169.95x10^3

Case -2 For 20% Increase,

Velocity,V = 12m/s

Re = 203.94x10^3

Case -3 For 40% Increase,

Velocity = 14m/s

Re = 203.94x10^3

Case -4 For 100% Increase,

Velocity = 20m/s

Re = 339.90x10^3

End time Calcultion:

Results:

Cut plots for velocity 10m/s

Cut plots for Pressure 10m/s

Cut plots for velocity 12m/s

Cut plots for Pressure 12m/s

Cut plots for velocity 14m/s

Cut plots for Pressure 14m/s

Cut plots for velocity 20m/s

Cut plots for Pressure 20m/s

Conclusion:

As reynolds number increases Velocity also increases