Inviscid fluid flow past a square cylinder.

Click For Summary
SUMMARY

The discussion focuses on the complexities of simulating inviscid fluid flow around a square cylinder, contrasting it with the more commonly studied circular cylinder. Key issues include the potential for vortex shedding at sharp corners, which contradicts the principles of inviscid flow. Finite difference simulations indicate that vortices may form, despite the expectation that inviscid flow should not exhibit spontaneous rotation. The conversation highlights the nonphysical nature of infinite acceleration at sharp edges and the necessity for inherent damping in simulations to achieve convergence.

PREREQUISITES
  • Understanding of inviscid fluid dynamics
  • Familiarity with finite difference simulation techniques
  • Knowledge of vortex dynamics and flow separation
  • Basic principles of incompressible flow
NEXT STEPS
  • Research "Inviscid flow theory and applications"
  • Study "Finite difference methods for fluid dynamics"
  • Explore "Vortex shedding mechanisms in fluid flow"
  • Investigate "Numerical methods for simulating incompressible flows"
USEFUL FOR

Fluid dynamics researchers, computational fluid dynamics (CFD) practitioners, and engineers interested in the behavior of inviscid flows around complex geometries.

tarnhelm
Messages
17
Reaction score
0
The flow of an inviscid incompressible fluid around a circular cylinder is commonly studied in fluid dynamics courses. There's a wikipedia article about it here: http://en.wikipedia.org/wiki/Potential_flow_around_a_circular_cylinder.

However, what about a square cylinder? There seem to be issues with simulating such flow across sharp edges or boundaries like the corners of squares. Can somebody tell me what you expect with such a scenario?
 
Physics news on Phys.org
Actually a colleague of mine is about to publish a paper in the Journal of Fluid Mechanics on the viscous flow past a square cylinder. It is a very similar flow field to a circular cylinder but te vortex shedding is more complex. I'd say keep an eye on JFM for it, but it will probably be a year before it is actually published.
 
Thanks for that. I think there's a lot of stuff out there about viscous flow past a square cylinder. However, inviscid flow presents a problem because it may be the case that vortices are produced at the corners, which I don't think should be the case in inviscid flow. At the very least, finite difference simulations seem to produce this effect. As I understand it, steady incompressible inviscid flow shouldn't spontaneously develop rotation like this. I'm wondering if anybody has any more info about it, because google isn't turning up much!
 
The problem is that a truly inviscid flow can turn around an arbitrarily sharp corner, which causes infinite acceleration of the fluid. This is clearly nonphysical. There isn't really a solution to this, which is why it is mostly ignored. If you decide to allow infinite acceleration, it would be qualitatively similar to the circular cylinder in terms of streamlines, but the corners would effectively be singularities in the flow. As for simulations, they have to have some inherent damping in order to converge, so they will never simulate truly inviscid flow.

Out of curiosity, why the interest in inviscid flow around corners? It's quite far from any physically realizable flow.
 
A square cylinder? Someone will have to explain what that means to me.
 

Similar threads

High School Fluid Flow Deflection Bending Ahead of Airfoil?
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Work - Energy Principle Application to Fluid Flow
  • · Replies 48 ·
2
Replies
48
Views
5K
Doublet flow in Fluid Dynamics between two spheres or cylinders
  • · Replies 0 ·
Replies
0
Views
2K
Graduate Potential flow, inviscid flow, incompressible flow
  • · Replies 17 ·
Replies
17
Views
4K
Graduate Applicability of potential flow theory (fluid dynamics)
  • · Replies 3 ·
Replies
3
Views
3K
Q: Fluid drainage along the outside of an inclined cylinder
  • · Replies 5 ·
Replies
5
Views
1K
Undergrad Laminar-turbulent transition and Reynolds number
  • · Replies 5 ·
Replies
5
Views
2K
Graduate How to simulate a membrane in a (2D) fluid?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Stressing Over Stress Tensor Symmetry in Navier-Stokes
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Fluid stream on a Curved Surface
  • · Replies 3 ·
Replies
3
Views
3K