Flow over a cylinder
FLOW OVER A CYLINDER
AIM:
The Main objective of this challenge is to simulate the flow over a cylinder and calculate the pressure and velocity for three different reynolds numbers.
INTRODUCTION
Flow over a cylinder has been studied extensively, both experimentally and numerically, for several decades. The simplicity of the geometry and the abundance of interesting flow features continue to make this flow subject of many current studies. Recent increase in computer power has prompted detailed numerical studies of this flow at higher Reynolds numbers.The flow over a cylinder exhibits vastly different behaviors as the Reynolds number, based on the free-stream velocity, cylinder diameter, and kinematic viscosity, increases from zero to large values. Steady laminar flow exists at Reynolds numbers up to approximately ReD;40 with a pair of symmetric counter-rotating vortices forming behind the cylinder at ReD. The presence of various regimes in the flow over a cylinder makes computations of this flow an interesting and challenging task. . Two-dimensional calculations have long been routine and are often used to validate numerical techniques and computer codes.
CALCULATIONS
Re = rho*U_inlet*D/mu
D = cylinder diameter(0.01m)
mu = dynamic viscosity(0.0000193N-S/m^2)
rho = density(1.2754kg/m^3)
Inlet Velocity=5 m/s
After submitting the above values in the formula we get Re=3304.14
Taking that value as 100% and calcualting the values of Re for 120%,140%,200%. We get
Re=3964.97 at 120%, Re=4625.79 at 140%, Re=6608.28 at 200%
Submiting the above Re values in Formula to get 3 different inlet velocities
Inlet_velocity=5.9 (at Re=3964.94)
Inlet_velocity=6.9(at Re=4625.79)
Inlet_velocity=10(at Re=6608.28)
PROCEDURE
- Open new solidworks part file and click on front plane to sketch
- Draw a circle with 0.01m diameter and extrude it
- Open flow simualtion wizard and give the following inputs
Flow= external(time dependent)
Fluid=Air(Laminar and turbulent)
Inlet_velocity=5m/s,5.9m/s,6.9m/s,10m/s(Along x direction)
- Check the intitial mesh conditions and run the simulation
- Once the simulations are completed, make a cut plot and create animations for pressure and velocity
RESULTS
Velocity of 5m/s( at Re=100%)
Velocity of 5.9m/s( at Re=120%)
Velocity of 6.9m/s( at Re=140%)
Velocity of 10m/s( at Re=200%)
Pressure of 5m/s ( at Re=100%)
Pressure of 5.9m/s( at Re=120%)
Pressure of 6.9m/s( at Re=140%)
Pressure of 10m/s( at Re=200%)
PART FILE
https://drive.google.com/file/d/1OMaaQm-sxEgK7MeYf0UWuQlT7C9Gtyy7/view?usp=sharing
CONCLUSION
From the above animations, it is clear that pressure do not have major role with the reynolds number when compared to velocity because the pressure plots are all similar