JF-17 Thunder Multirole Fighter [Thread 7]

[Maxpane]

Drop tanks,plenty of them..

View attachment 448303

beauty

 

[Chak Bamu]

Drop tanks,plenty of them..

View attachment 448303

Those weld seams do not look very good. I bet they add appreciable amount of drag by increasing the turbulent flow around them.

 

[CriticalThought]

Those weld seams do not look very good. I bet they add appreciable amount of drag by increasing the turbulent flow around them.

Just see the number of rivets all over the plane from up close.

 

[Chak Bamu]

Just see the number of rivets all over the plane from up close.

I was only considering the fuel tanks. Rivet is a point, seam weld is a round circle. Therefore their effects are different. eg, while rivets would add drag, Rivets a-top wings would enhance turbulent flow and improve lift. Circular seam welds would do nothing but add drag.

 

[CriticalThought]

I was only considering the fuel tanks. Rivet is a point, seam weld is a round circle. Therefore their effects are different. eg, while rivets would add drag, Rivets a-top wings would enhance turbulent flow and improve lift. Circular seam welds would do nothing but add drag.

The point is that overall performance remains unaffected by such minor deformities. They would be more relevant at higher speeds. By the way, can you provide any reference that says rivets cause the vortices that provide lift?

 

[Chak Bamu]

The point is that overall performance remains unaffected by such minor deformities. They would be more relevant at higher speeds. By the way, can you provide any reference that says rivets cause the vortices that provide lift?

No need to provide reference. Any engineer worth his name can understand this. Why bother, though?

 

[CriticalThought]

No need to provide reference. Any engineer worth his name can understand this. Why bother, though?

Now you really need to provide reference, because anyone who can perform a google search can see you are talking BS.

https://en.wikipedia.org/wiki/Vortex_generator

https://microaero.com/image-gallery/

 

[Chak Bamu]

Now you really need to provide reference, because anyone who can perform a google search can see you are talking BS.

https://en.wikipedia.org/wiki/Vortex_generator

https://microaero.com/image-gallery/

I am not here to educate you. Next thing you would demand might be to provide reference that chicken eggs are mostly white & oval. So, sorry - I am not playing google with you. If your feelings are hurt over seam welds or rivets and that is your problem, not mine.

 

[CriticalThought]

I am not here to educate you. Next thing you would demand might be to provide reference that chicken eggs are mostly white & oval. So, sorry - I am not playing google with you. If your feelings are hurt over seam welds or rivets and that is your problem, not mine.

I don't think you got my point at all. I am saying an ex Mod shouldn't be spreading BS on the forum. Such false information can be tolerated by others but not someone with a title to his name.

 

[Path-Finder]

https://twitter.com/x/status/953840980251369474

 

[Rafael]

^Is this an AESA for JF-17?

 

[Ultima Thule]

^Is this an AESA for JF-17?

Expected for blk-3

 

[Chak Bamu]

I don't think you got my point at all. I am saying an ex Mod shouldn't be spreading BS on the forum. Such false information can be tolerated by others but not someone with a title to his name.

OK. Here goes:

1. I can substantiate my point. But it is not that important. The thread would veer towards a discussion of aerodynamics.
2. Though I am an engineer, I am not an expert in aerodynamics. My life-long fascination with aircraft has led me to learn, experiment, & enjoy this study. I was 8 or 9 when I first noticed that rough upper wing surface helps with lift, though with addition of drag. Subsequent experimentation & occasional study confirmed it. But I did not want to waste time to make a minor point.
3. Notice the choice of words in my post where I pointed out seam welds on fuel tanks: an appreciable addition of drag need not be a serious concern; but it should be a concern nonetheless . But you thought that my pointing out seam welds was important enough to point out rivets on metal skin.
4. Having a small bit of experience with metal working, I can tell how the manufacturing method could be modified to remove seam welds. It would add cost, no doubt. But if a decision-maker resolved that each and every part relating to JF-17 should be designed to improve the aircraft's performance then these seam welds would not be there, and neither would there be protruding rivets (or at least not many of them). It may happen or it may not. But the point stands on its own merit.
5. Not being a moderator is a relief. I do not have to hold myself to a higher standard. My views have evolved over the past few years and I should not be a moderator at a forum where nationalism is celebrated to the point of worship almost. So, I really do not care about any title that appears under my user name and I suggest that neither should you.

In any case. I believe that I wasted my & other people's time writing this post. I hope we can drop this matter here. Take care.

 

[CriticalThought]

OK. Here goes:

1. I can substantiate my point. But it is not that important. The thread would veer towards a discussion of aerodynamics.
2. Though I am an engineer, I am not an expert in aerodynamics. My life-long fascination with aircraft has led me to learn, experiment, & enjoy this study. I was 8 or 9 when I first noticed that rough upper wing surface helps with lift, though with addition of drag. Subsequent experimentation & occasional study confirmed it. But I did not want to waste time to make a minor point.
3. Notice the choice of words in my post where I pointed out seam welds on fuel tanks: an appreciable addition of drag need not be a serious concern; but it should be a concern nonetheless . But you thought that my pointing out seam welds was important enough to point out rivets on metal skin.
4. Having a small bit of experience with metal working, I can tell how the manufacturing method could be modified to remove seam welds. It would add cost, no doubt. But if a decision-maker resolved that each and every part relating to JF-17 should be designed to improve the aircraft's performance then these seam welds would not be there, and neither would there be protruding rivets (or at least not many of them). It may happen or it may not. But the point stands on its own merit.
5. Not being a moderator is a relief. I do not have to hold myself to a higher standard. My views have evolved over the past few years and I should not be a moderator at a forum where nationalism is celebrated to the point of worship almost. So, I really do not care about any title that appears under my user name and I suggest that neither should you.

In any case. I believe that I wasted my & other people's time writing this post. I hope we can drop this matter here. Take care.

On the topic of JF-17, fuel tanks, and seam welds, an aircraft is a highly optimized system of inter-related and interacting components. No one in their right minds would just throw some metal together and tack it onto an aircraft. Every system has given tolerances, and any design within tolerance limits is acceptable. That was the whole point of pointing out rivets - which are another irregularity on the surface that can theoretically cause the boundary layer to exhibit abnormal behaviour. But at the speeds for which Thunder is designed - Mach 1.6 - they do not matter.

If indeed the tanks have been carelessly welded together without thought to impact on drag, then it would be a black mark on the professional conduct of PAC personnel and PAC as a manufacturer. That said, there is always room for improvement, and we have been hearing the fantasies of various members on multiple threads in this regard.

Now, the interesting thing is whether Block 3 will increase the max speed to Mach 2. At that speed, the tolerances will have to be nearer to what is expected on F-16s.

 

[araz]

On the topic of JF-17, fuel tanks, and seam welds, an aircraft is a highly optimized system of inter-related and interacting components. No one in their right minds would just throw some metal together and tack it onto an aircraft. Every system has given tolerances, and any design within tolerance limits is acceptable. That was the whole point of pointing out rivets - which are another irregularity on the surface that can theoretically cause the boundary layer to exhibit abnormal behaviour. But at the speeds for which Thunder is designed - Mach 1.6 - they do not matter.

If indeed the tanks have been carelessly welded together without thought to impact on drag, then it would be a black mark on the professional conduct of PAC personnel and PAC as a manufacturer. That said, there is always room for improvement, and we have been hearing the fantasies of various members on multiple threads in this regard.

Now, the interesting thing is whether Block 3 will increase the max speed to Mach 2. At that speed, the tolerances will have to be nearer to what is expected on F-16s.

Chak Bamu is a respected poster. Being junior please learn to disagree with respect. Opening mouth without engaging brain leads to fights and unsightly arguments. So please bear that in mind.
Secondly may I know the source of the Mach 2 revelation that you have just posted. The reason I ask is that to my knowledge which indeed is very limited there is no fighter in existence that approaches mach 2 while utilizing DSI as a feature. Perhaps I might have missed something.
I do not know much about aerodynamics or aeronautical engineering but to support what Chak said, a small but well publicized change in block 3 is replacement of all the small antennas which jut out of the body. This was considered to be both and aerodynamic as well as( a sign of old age the right word escapes me totally- but your visibility on a radar----- Ahhhh!! Radar cross sectional area) blemish. It may also be pointed out that all efforts are made to remove the seems and rivets from Stealth fighters to reduce their radar signatures. I remember the holding bay doors of the J31s being shown extensively as an example.
Regards
A