CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Winglet cant angle effects

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 31, 2017, 20:35
Default Winglet cant angle effects
  #1
Member
 
Ferruccio Rossi
Join Date: Jun 2016
Location: Melbourne, FL USA
Posts: 91
Rep Power: 6
frossi is on a distinguished road
I am conducting a study of the effects caused by changing the winglet cant angle. In particular, I am observing how drag, lift, and L/D of the whole wing change as the winglet cant angle is changed.

Wing
My wing has a dihedral of 6 deg, and thus I consider the winglet to be "flat" (0 cant angle) when it has an angle of 6 deg from the horizontal.

Winglet
The winglet cant angle is changed from 0 cant angle (same deflection as wing dihedral) to 60 deg, at increments of 3 deg.

Conditions
My wing (as seen in the picture) has an angle of attack of 7.5 deg, a velocity of Mach 0.392. The ambient conditions are those at 3,000 m altitude.

As you can see from my graphs:
1) The values before 42 deg winglet angle seem to oscillate

2) There is a huge jump in both lift and drag from 42 deg winglet deflection to 45 deg winglet deflection. How can a 3 deg change give this much of a difference?

3) The pattern after 45 deg winglet seem more stable and reasonable. Why is this?

It looks like when the winglet is at 45 deg (39 deg from the horizonatal) something changes, either in the physics or the math, so that my results change drastically. I thought it may be an error in the way in which the software calculates lift, or maybe the force components, due to the fact that the winglet is inclined compared to the wing, but I cant figure it out.
I also thought it may be the way in which I define the force components, but they look right.

I define lift as:
x-component: -sin(7.5)
y-component: cos(7.5)

I define drag as:
x-component: cos(7.5)
y-component: sin(7.5)

What could be the cause of my results? should I define lift and drag differently for the wing? Could it be that Fluent is not resolving the components on the winglet because it is angled? Is it a geometry problem or a physics problem?

Thank you all for your help.
Attached Images
File Type: png drag.PNG (18.5 KB, 8 views)
File Type: png lift over drag.PNG (17.5 KB, 9 views)
File Type: png lift.PNG (20.2 KB, 7 views)
File Type: png wing_3D.png (73.3 KB, 7 views)
File Type: png wing_top (1).png (75.2 KB, 5 views)

Last edited by frossi; April 1, 2017 at 01:34.
frossi is offline   Reply With Quote

Reply

Tags
angle, drag, lift, mesh, winglet

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Influence of changing the winglet cant angle frossi FLUENT 3 April 3, 2017 20:33
Winglet parametric study frossi CFX 1 March 13, 2017 18:31
Dynamic contact angle calculation in multiphaseInterFoam rajeshchem OpenFOAM 2 January 31, 2014 08:52
[Netgen] Import netgen mesh to OpenFOAM hsieh OpenFOAM Meshing & Mesh Conversion 32 September 13, 2011 06:50
Normal vector, slope and aspect angle g_niro Main CFD Forum 0 February 2, 2011 18:24


All times are GMT -4. The time now is 10:17.