Antisymmetric modeling for panel method solver

In summary: Overall, the conversation discusses how to define planes of flow symmetry or antisymmetry in Pan Air. For symmetric flow, you can define half the configuration. For antisymmetric flow, the configuration needs to be defined for the entire model. Figure 5-5 provides a summary of the planes of symmetry and recommended placement of the configuration. Some confusion arises when defining antisymmetry, as there are no provided samples. However, it is believed that for antisymmetry about the XZ plane with the full model entered, Yimage = -Y, Ximage = -X, Zimage = Z.
  • #1
Ryoko
114
5
This is a section from the Pan Air user's guide (Pan Air is a aerodynamic panel-method flow solver).


To define the planes of flow symmetry or antisymmetry, enter one of the blocks of data
defined below.

Input Data for Flow Symmetry
$SYMMETRIC FLOW ABOUT XZ PLANE
=XZPLN XYPLN
1.0 0.0

! Inputs half configuration
$SYMMETRIC FLOW ABOUT XZ AND XY PLANES
1.0 1.0
! Inputs quarter configuration

$SYM - UNSYMMETRIC FLOW (DEFAULT VALUE)
0.0 0.0
! Inputs full configuration

$SYM - ANTISYMMETRIC FLOW ABOUT XZ PLANE AND SYMMETRIC FLOW ABOUT XY PLANE
1.0 -1.0
! Inputs half configuration

$SYM - ANTISYMMETRIC FLOW ABOUT XZ PLANE
-1.0 0.0
! Inputs full configuration above or below XZ plane

Most configuration and flow analyses have one plane of symmetry. For this type of
problem, you only need to define half the configuration. Onset flow is defined with a zero
angle of yaw. This approach represents a considerable savings over an analysis of the
complete configuration. A summary of the planes of symmetry and the recommended
placement of the configuration are given in figure 5-5.

I'm confused by the symmetry and anti-symmetry. The first one is easy enough: mirror about the XZ plane (Yimage = -Y, Ximage = X, Zimage = Z). The third one is no symmetry applied. Also easy. But the ones describing the antisymmetry have me stumped because they didn't provide any samples of how they define antisymmetry. For example, the last one is antisymmetry about xz with the full model entered. Does this mean that:

Yimage = -Y, Ximage = -X, Zimage = Z

or does it mean:

Yimage = -Y, Ximage = X, Zimage = -Z?

Or maybe it means something else entirely. Thoughts?
 
Engineering news on Phys.org
  • #2
I think it's the first one. Yimage = -Y, Ximage = -X, Zimage = Z
 

1. What is antisymmetric modeling?

Antisymmetric modeling is a technique used in panel method solvers to simulate the flow of a fluid around a body by dividing the surface of the body into panels and solving mathematical equations to calculate the pressure and velocity at each panel. Antisymmetric modeling specifically involves taking into account the symmetry of the body, which can reduce computation time and increase accuracy.

2. How does antisymmetric modeling benefit panel method solvers?

Antisymmetric modeling can significantly reduce the computational cost of panel method solvers by taking advantage of the symmetry of the body being simulated. By only solving for one half of the body and applying symmetry conditions to the other half, the number of calculations needed can be greatly reduced. This can also lead to more accurate results, as symmetry conditions can help smooth out any numerical instabilities.

3. What types of symmetries can be taken into account in antisymmetric modeling?

Antisymmetric modeling can take into account various types of symmetries, such as planar symmetry (mirror symmetry about a plane), cylindrical symmetry (rotation symmetry about an axis), and spherical symmetry (rotation symmetry about a point). The type of symmetry used will depend on the shape of the body being simulated.

4. Are there any limitations to using antisymmetric modeling in panel method solvers?

While antisymmetric modeling can greatly benefit panel method solvers, it does have some limitations. The body being simulated must have some form of symmetry for this technique to be effective. Additionally, the accuracy of the results may be affected if the symmetry conditions do not hold exactly or if there are flow features that are not symmetric.

5. How does antisymmetric modeling compare to other techniques used in panel method solvers?

Antisymmetric modeling is just one of many techniques used in panel method solvers to simulate fluid flow around a body. Other techniques include vortex lattice methods and boundary element methods. Each technique has its own advantages and limitations, and the most suitable method will depend on the specific application and the desired level of accuracy.

Similar threads

  • Nuclear Engineering
Replies
1
Views
1K
Replies
2
Views
628
  • General Math
Replies
6
Views
2K
Replies
17
Views
3K
  • Quantum Physics
Replies
5
Views
2K
  • Mechanical Engineering
Replies
23
Views
36K
  • General Engineering
Replies
27
Views
8K
Replies
18
Views
1K
  • Beyond the Standard Models
Replies
1
Views
2K
  • Poll
  • Science and Math Textbooks
Replies
1
Views
5K
Back
Top