hinge moment

[s.m]

hello guys

how do i can calculate hinge moments in VSPAero? i modeled control surfaces in sub tab but the aerodynamic coefficient of control surface doesn't report in the LOD file.

i think the solution is that to model control surfaces as a  independent from main wing but it seem be very difficult. what is the best solution?

[corp...@gmail.com]

I think that it much depends from the level of accuracy you are searching for.

Hinge moments are highly affected  by controls geometry, hinge location and control surface shape. I would calculate them separately rather than to expect such values from vlm/panel analysis,

using classical methods as those explained in Datcom for example , unless of more sophisticated tools are available.

In VSPAero you could design only the portion of the wing interested by control surfaces , using flapped airfoil coordinates in order to obtain Cp curves from

which deduce in some way hinge moments.

 But the same problem could be solved more quickly  by an Xfoil analysis of the flapped airfoil in order to obtain the necessary coefficient for

calculating hinge moments. In any case , the slot between main wing element and control surface is not taken in account, therefore some simplification must be introduced.

Corrado

[s.m]

thank you for you reply, Corrado

i read a pdf workshop that offer to produce wing and flap separately as can be seen in the attached picture. how is possible in the openVSP to create this wing? wing component is a prepared geometry and just some parameters like tip and root chord can be changed by user. is there any tutorial for this picture?  

[corp...@gmail.com]

No picture attached.

[s.m]

sorry i did

On Tuesday, January 23, 2018 at 2:54:42 PM UTC+3:30, corp...@gmail.com wrote:

No picture attached.

[corp...@gmail.com]

I tried time ago to design such configurations just to verify how much close to a real case I could go with OpenVSP.

My attempt was as follows:

1)    1 )  Split the wing in order to have a section where is placed the  transition section  of the picture.

2)      2) Such transition section will have a span close to zero, root chord equal to the inboard section,tip chord equal to outboard section , in this case the main wing element chord.

3)      3) Go to subsequent outboard section and build the wing geometry related to high lift devices area

4)    4)   Proceed outboard and If another transition is necessary goto point 1)

5)     5)  Build subsequent outboard sections in the same manner, following the chordwise and spannwise geometry of the wing.

The problem is that the sections where high lift devices are located have an airfoil section necessary to build the main wing element only ( then a specifically  designed airfoil), while the flap/aileron elements require an additional wing properly positioned respect to the first one in order to complete the “assembly” wing+surface controls.

Interesting to know if others tried different and more efficient ways.

Corrado

[Erik Olson]

The image comes from one of my workshop presentations. To construct the high-lift geometry in this manner in OpenVSP is a complex process and I had to create an automated routine to build and position the individual high-lift components through vspscript. It would take a very long time to do by hand.

[corp...@gmail.com]

Hi Erik,

I read that interesting presentation and it was one of the reason that suggested to me to make some attempt in exploring
how much hard could be to manage such complicate geometries in OpenVSP.

I have recovered only the file where i tried to design a generic high lift portion ( but redesigned again in Release 3.15),
but unfortunately I don't find anymore the whole wing file.

I remember that the big problem was to create an adequate transition between the unflapped and flapped region, due to the difficulty
to manage a sudden change in airfoils locally, that is the whole airfoil for unflapped region and the main wing element airfoil in the
flapped one.
Nevertheless the result could be acceptable, in the limits of the tool capabilities and of my knowledge in using it properly for such task.

Do you think that such procedure could be implemented in the actual architecture of OpenVSP or its integration  would require too much effort and therefore not practical ?

Corrado

[Erik Olson]

It's possible that a capability could be built directly into OpenVSP, but it would be a substantial undertaking. To my knowledge it's not in the scope of any current tasks that are being funded by the various stakeholders.

[corp...@gmail.com]

Thank you Erik

[s.m]

can you describe more about "automated routine" and your "vspscript"? is there any useful text or anything that help me for start this work? this is a part of my thesis. i should calculate hing moment of a control surface and therefore i had to create control surface and wing separately.

[s.m]

thank you so much Corrado. I'll use your guidelines in my work.