Aerowerx
Well-Known Member
It seems that I keep coming back to where I was a year ago---some type of tandem pusher configuration.
I am currently trying to decide if it should be tailless or not.
In XFLR5 I can easily come up with a design that has decent longitudinal dynamic stability but have been having trouble with the lateral dynamic stability. I can get an acceptable damping factor but then the natural frequency is quite low. According to MIL Spec 8785C, for Dutch Roll the damping factor times the natural frequency should be greater than 0.35 radians/sec. which is about 0.055 Hz. What I am seeing is below this.
I have also seen low damping factors (below 0.190) with high natural frequencies (around 5-6 Hz). Looks like it would be quite uncomfortable to ride in.
The 'rules' in MIL Spec 8785C are for conventional aircraft, so do they apply for tailless?
Another question...Do the same static margin 'rules' apply for a tailless design?
[Hope this makes sense...I was interrupted 4 times when trying to type it...."Better Half" is still recovering from surgery]
I am currently trying to decide if it should be tailless or not.
In XFLR5 I can easily come up with a design that has decent longitudinal dynamic stability but have been having trouble with the lateral dynamic stability. I can get an acceptable damping factor but then the natural frequency is quite low. According to MIL Spec 8785C, for Dutch Roll the damping factor times the natural frequency should be greater than 0.35 radians/sec. which is about 0.055 Hz. What I am seeing is below this.
I have also seen low damping factors (below 0.190) with high natural frequencies (around 5-6 Hz). Looks like it would be quite uncomfortable to ride in.
The 'rules' in MIL Spec 8785C are for conventional aircraft, so do they apply for tailless?
Another question...Do the same static margin 'rules' apply for a tailless design?
[Hope this makes sense...I was interrupted 4 times when trying to type it...."Better Half" is still recovering from surgery]
