[MBDyn-users] Aerodynamic Elements - Modeling a Flapping Wing Microsystem
mantegazza at aero.polimi.it
Thu Jul 1 18:32:59 CEST 2010
Pierangelo Masarati wrote:
> David Cross (Civ, ARL/VTD) wrote:
>> MBDyn Users,
>> I am trying to build a model which matches an experimental setup of a
>> flapping wing micro-system. The experimental model uses a
>> polyethylene film as the wing surface, with only a leading edge spar.
>> Currently I have a 2D mesh representing the wing surface using type
>> beam2. The problem is making the energy of this mesh equivalent to
>> the continuum of the polyethylene film. I am wondering if there is a
>> better way to model a continuous surface, say through aerodynamic
>> beams, which I have seen used in rotor blade examples. However, I
>> would not want these beams to model an airfoil, rather a continuous
>> surface of a prescribed thickness and material.
>> Looking at the documentation and some examples of the aerodynamic
>> beams being used for rotor blades, I am just a little unsure of the
>> direction to take my model. Any suggestions would be greatly
>> Sorry for this being somewhat of a modeling question. My MBDyn
>> experience is limited at this point, and would benefit greatly from
>> other users who have more experience than I.
> I don't quite understand this request, taking into account your initial
> message. The "aerodynamic beam" implements aerodynamic forces, so it
> has little to do with modeling the structure. With respect to
> aerodynamics, I infer from your previous message that you are trying to
> couple MBDyn to an external CFD solver.
> In released versions of MBDyn there is no straightforward way to model
> shell-like elements from a structural point of view. I understand that
> using trusses of beams is not easy.
> We have implemented a shell beam (plate + membrane), and we're
> validating it. As soon as we are able to address some minor issues, I
> think it could be released shortly, say during the summer. If you like,
> I can send you a snapshot of the code.
> Implementing a pure membrane element could be an interesting
> development. In principle, it would be even easier than the shell
> element. However, we had to prioritize the shell element. I think for
> some flapping wing microsystem design (insect-like, insect-size), where
> the wing is essentially modeled using thin films it would possibly be
> more appropriate than the shell element.
> In any case, regardless of the modeling approach, a wing model that
> allows the wing camber to change arbitrarily as a consequence of elastic
> deformation would prevent the use of 2D aerodynamics based on table
> lookup; for sure, it would not be feasible using 2D aerodynamic models
> current supported by MBDyn.
> Please let me know if we can be of help.
> Cheers, p.
What about modeling it as a modal mbdyn elements using an external program?
> MBDyn-users mailing list
> MBDyn-users at mbdyn.org
More information about the MBDyn-users