PhD in Aerodynamics and my son is doing his PhD in Astrophysics.
Actually my question was about your topic...like the exact area you worked on in your PhD or better asked, "what was the title of your dissertation report?"
If its available online, you can save the explanation and throw in the link or any of your research papers.
So you can ask me anything regardless of what you think is a stupid question, is actually not stupid. knowledge is knowledge no matter what others say. There are a very few people who have really seen a Fighter let alone fly one, You might be very educated but sitting a flying is a totally separate thing and having a couple of boogies under your belt makes hell of a difference.
That's very kind of you.
So ask anything except weapons I will not go into details unless PAF has openly told everyone. I hope you can understand.
Oh, don't worry, my questions are rather about aerodynamics than PAF and any PAF specific question would be general. I can understand that things in the armed forces are pretty sensitive and sometimes even things we may consider normal as classified.
So fire away sometimes I am busy with job and grandkids so reply might be late which I appologise my wife has already said that Defence.pk is my Sawtan
A waring for NEO and ASIM if she lands in your city vanish
it takes her 1 sec from becoming a good house wife to bruce lee
.
Let's hope she doesn't read this part
My first question:
This question arises from rumors about JF-17 will possibly have a future twin-tail version. Its been rumored around by all and sundry but also reported by some rather respectable people that we "should expect a twin-tail version in the future".
So the question is : What advantages would a
light weight ,twin-tail, presumably
single engine plane offer to the
airforce?
The bolded part seems interesting (to me). My limited knowledge tells me at a first glance that twin tails may have several advantages...like reduction in height ... which is helpful in putting them in a hanger (particularly interesting for Navy), reduction is RCS , shorter take off because a canted twin-tail also have the vertical component of the airflow that might add to the lift, helpful in maintaining balance in twin-engine if one engine fails or provides unequal thrust, etc but has a disadvantage in that it increases weight which is of significant importance to a light weight aircraft.
All the above features (with the exception of reduction in RCS) suits the Navy better. No wonder F-14, F-18, was mostly in the US Navy use (although they were used by airforces of other nations like Iran , Australia, Spain,etc). Infact, and if I am not wrong, the F-16 and the F-18 were in direct competition at the design stage both hoping to impress the forces for their then next generation light-weight fighter. The USAF chose the F-16 while the US Navy preferred the F-18 both with slight modifications.
Other twin-tail fighters, however, have been used by airforces like the Sukhoi Su-27, F-22, F-35, etc but atleast all these and the one used by the Navy were twin engines and heavy weight (OK, F-35 has one but a mammoth one) .Of these, the Su-30 and the F-15 both had pure vertical twin-tails unlike the hornet. Here I have omitted older designs because presumably with advances in understanding of aerodynamics, later designs are much more optimized. I also excluded the the F-14 having vertical tails because it has another unique feature in that it can change its aspect ratio.
Light/medium weight single engine popular design do not use the twin-tails e.g F-16, EF-2000, Rafale, Grippen, JF-17, J-10, LCA, etc.
In summary, the question(s) is/are:
- what advantages or disadvantages would a twin-tail design give to the JF-17 or any other signe-engined fighter?
- How do these advantages/disadvantages compare with primary role of airforce/Navy in addition to what I have stated? (like in why USAF went with F-16 while USN with F-18 while other airfroces did opt for F-18)
- How does a vertical twin tail / canted twin tail relate to other features like aspect ratio, wing design,dihedral angle, sweep angle etc and characteristics of the plane like flight regime?
I presume the answer to each of these sub-questions would be rather long, so please take your time and if you wish you can answer one part at a time. Also, if you have some online resource for
easy reference or know of any video lectures, graphical explanation on any of these topics, it would be highly appreciated.
Many thanks in advance.
P.S. Oh, just a note...Mods/ Admins, if this thread isn't the right place for this discussion, you can move it to a more appropriate place since this thread is primarily related to air force questions rather then aerodynamics of planes.
