123
In Ukraine, a drone with a jet engine and a flight range of 400 kilometers has been developed
(odessa-journal.com)
this post was submitted on 05 Sep 2023
123 points (100.0% liked)
Ukraine
174 readers
12 users here now
News and discussion related to Ukraine
*Sympathy for enemy combatants is prohibited.
*No content depicting extreme violence or gore.
*Posts containing combat footage should include [Combat] in title
*Combat videos containing any footage of a visible human must be flagged NSFW
Donate to support Ukraine's Defense
Donate to support Humanitarian Aid
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
I would think it's got to do with spanwise flow. The forward swept design brings the spanwise flow toward the fuselage and allows for more effective control of the ailerons when traveling at transonic speeds like can be expected from a "drone/missile/UAV" like this.
It also allows for a reduction in vortices formed by the wingtip which would increase drag and decrease efficiency. That means you can get away with a smaller wing, decreasing weight and either increasing your payload or maximum range.
If it were beneficial in total, most transonic planes would have it. The only aerodynamic advantage over backward swept wings is higher manoeuvrability, which isn't a priority here. This isn't a dogfighter. My money is still on better payload distribution.
Not sure what that means. I don't think agility is a priority with a jet-powered drone. Or benign stall characteristics.
That is negligible. We know how to reduce wingtip vortices, and reverse sweep is not the answer. Raked wingtips as used on the 787 and the larger-wing versions of the 777 and the 777X are optimal for transonic flight. Blended winglets are a close second, as used on the A350 and A330neo. Again, not forward sweep.
This thing also does not look very refined aerodynamically, and there are many more things that could be done to reduce drag that are much cheaper. Wing-body fairings come to mind to reduce interference drag, or winglets if you really want to go there. This has all the looks of "Eh. Good enough. Send it!", which makes sense given the urgency.
I think they don't have at their disposal a proper aerodynamic tube. Perhaps you would kindly recommend some software to model the aerodynamic properties?
That's the point. This is not a very refined design, it is a quick-and-dirty, "good enough" approach to get it out of the door as quickly as possible while still fulfilling the requirements. Which is why I found it surprising that forward sweep was deemed the best option, despite its aerodynamic and structural challenges (which usually outweigh any benefits). And as I said, fuel efficiency was not foremost on the designers' minds. Case in point: small turbojets are notoriously inefficient (only pulsejets and rockets are worse), and many small details could be improved cheaply. But having a large unobstructed payload bay is a very good reason for forward-swept wings on such a small design and can greatly simplify operation. I will not recommend any computational fluid dynamics package, because it takes many years of study and experience to apply it to real-world problems meaningfully. And if the design team includes aerodynamicists, they will know what software to use anyway, and don't need my recommendation. Surprisingly, if you have good data on the airfoil cross-section performance, X-Plane is not the worst tool to get a good idea of performance and stability. It was used for Solar Impulse in that way (also for pilot training).