Blade element model

[simulator78]

Hi,

I am working on helicopter rotor simulation using blade element model and have a question about how to compute the forces and moments at the hub.

I have N blades which are connected to the hub with a vertical and a horizontal hinge. Now, together with the helicopter body I have a pretty complex jointed structure. If I approach to this question from a rigid body simulation point of view I have to write down equations using forces,torques and the constraints of the hinges and solve them. Which is, of course, pretty complex.

So the question is, is there an easy way to compute the thrust and torque on the hub if I know the torques and forces acting on the blades?

Thanks in advance

 

[dimachorny]

Try this:
MODERN HELICOPTER DESIGN by Dr. Eric Hollmann and M. Hollmann

from

http://www.aircraftdesigns.com/books.html

 

[saksmito]

Everything depends on the accuracy of the model you need.
For a simple one I would reduce it to a first year degree problem. Sum the forces and moments acting on the blade and transport them to the hub.
I think it should be enough as a first aproximation, and if you don´t want to take into account flutter and aerodynamic inestabilities this should be enough.