Week 2 - Flow over a Cylinder.
AIM:Simulate the flow over a cylinder and explain the phenomenon of Karman vortex street.
OBJECTIVES
- Simulate the flow with the steady and unsteady case and calculate the Strouhal Number for Re= 100.
- Calculate the coefficient of drag and lift over a cylinder by setting the Reynolds number to 10,100,1000,10000 & 100000. (Run with steady solver)
- Discuss the effect of Reynolds number on the coefficient of drag. [ Results should be validated with any standard literature and error should be within 5 %]
Expected results:-
- In both approaches, show that the flow has converged. That is, what quantities or plots need to be looked at to determine that the flow has converged?
- Plots of the coefficient of drag and lift.
- Plots to show vortex shedding behind the cylinder.
- Mention the referred material (Reference Paper or Fluid Mechanics Textbook) at the end of the challenge submission page.
2.Meshing
3. set up for steady and transient state
performing mesh check
defining the physics of the problem
defining material properties (air density and viscosity)
defining inlet boundery conditions
defining outlet bounderyy conditions
creating moniter point
velocity and pressure plots at monitering points
references
for calculationn of drag
for calculation of lift
residual plots
initialization
creating solution animation
velocity and pressue contours
results for steady state Re= 100
residual plots
velocity plot
prssure plot
coeffcient of lift plot
coefficient of drag
velocity and pressure contours
at cfd post
TRANSIENT SIMULATION RESULTS AT RE=100
STROUHAL NUMBER=1.3579
Re=10
steadt state Re=1000
AT Re10000
Re 100000
REFERENCE PAPER
https://www.sciencedirect.com/science/article/pii/S0307904X08000243
CONCLUSIONS
1 transient simulation captures the data more accurately than the steady-state, because of the number of time steps
2 the von Karman vortex shedding has been visualized
3 Cd is inversely proportional to velocity and Re.
4 @Re=1=100 Cd=1.375