Please or Register to create posts and topics.

Regarding proper utilization of aeroelastic simulation outputs?

Hi Brian,

I think that the process that you describe is close to how stresses are obtained in practice. You compute loads with a lower order beam model and then apply these loads to a higher order model to obtain stresses.

Typically you split up these loads into the ultimate loads, the largest loads that the structure will experience during its lifetime, and the fatigue loads, which are oscillating loads that act on the structure for a large number of cycles.




Thank you for getting back to us. Another question we have is, would we use only the forces, or both the forces and the moments at the tips of the blades to be used as inputs on our connector/ torque tube FEA model? I ask because we are not sure if the forces are causing the moments, or if they are independent in this scenario.

Another issue we are running into is that the simulations are failing during or just after the ramp-up. We are using the fix ramp-up simulation method. If we set the TSR to anything above 3.5, the simulation fails due to what we believe is an incredibly high deformation of the blades, torque tube, and tower.  But what is interesting is that if the turbine can survive the ramp-up, the major deformation quickly subsides, and the deformations decrease to a much more acceptable level, on the order of 1 in, during the CFD portion of the simulation.

Hi Brian,

yes, you need to apply both the forces and moments to your FEA model.

Regarding the issue with the rampup: During the rampup time to rotor is accelerated to arrive at the specified rpm/TSR once the rampup time is over. If you keep the rampup time fixed and increse the rpm/TSR this means that the acceleration of the rotor is getting larger and larger. Simply try to increase the rampup time – that should solve you problem.