Hello,
I am trying to model a V-tail aircraft. I tried to model the V-tail by using a elevator plane with a large dihedral (35°, for a V-angle of 110°), but I noticed that tail volume coefficient does not seem to change when I change the tail dihedral. Is this the correct way to model a V-tail? Or do I have to convert V-tail setup into a conventional tail when modeling in XFLR5?
Thanks in advance,
Francesco
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Anonymous
-
2007-04-29
Francesco,
Defining the elevator with high dihedral is the best way.
It is true that in v3.19, the tail volume calculation does not take into account the cosine effect of the dihedral.
I will modify the formula in the next release to
Vh_Vtail = Sh*Cos(dihedral)²
André
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Anonymous
-
2007-04-30
Yes, that is correct.
The tail volume value is provided for information only, it is not used in the VLM calculation nor anywhere else.
André
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Thank you for the reply, André. So may I presume that VLM calculations take the tail dihedral into proper account, and that the "wrong" tail volume calculation is only contained in the plane geometry window?
Thanks,
Francesco
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello,
I am trying to model a V-tail aircraft. I tried to model the V-tail by using a elevator plane with a large dihedral (35°, for a V-angle of 110°), but I noticed that tail volume coefficient does not seem to change when I change the tail dihedral. Is this the correct way to model a V-tail? Or do I have to convert V-tail setup into a conventional tail when modeling in XFLR5?
Thanks in advance,
Francesco
Francesco,
Defining the elevator with high dihedral is the best way.
It is true that in v3.19, the tail volume calculation does not take into account the cosine effect of the dihedral.
I will modify the formula in the next release to
Vh_Vtail = Sh*Cos(dihedral)²
André
Yes, that is correct.
The tail volume value is provided for information only, it is not used in the VLM calculation nor anywhere else.
André
Thanks André, this is precious information.
My most sincere congratulations for your great work!
Francesco
Thank you for the reply, André. So may I presume that VLM calculations take the tail dihedral into proper account, and that the "wrong" tail volume calculation is only contained in the plane geometry window?
Thanks,
Francesco