Timeline for Are ducted fans more efficient?
Current License: CC BY-SA 3.0
11 events
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| Apr 29, 2017 at 1:58 | comment | added | Marius | Ah, I see. My apologies. Excellent question...it's hard to tell. The image I linked to isn't terribly descriptive, but this might be better: go to 1:36 of youtube.com/watch?v=jUnUe9dBKAI&t=3s. It appears that there is some deliberate shaping of the casing around the lift fan, which would indicate to me some intention to increase mass flow rate through the fan. I can't tell the duct geometry around the fan itself for sure because of the shadows, but I could believe that at least part of the fan is shrouded. What qualifies a duct for you? | |
| Apr 28, 2017 at 21:21 | comment | added | mins | Yes, that's what I was saying. But are the fans ducted? I'm not sure as the "duct" we see seems to be the duct where engine air circulates to turn the fan. | |
| Apr 28, 2017 at 18:25 | comment | added | Marius | Looking at this image (prototypes.free.fr/vtol/lift-fan/xv5_22.jpg) and listening this video made by Ryan (youtube.com/watch?v=fg9guWqKShs -- go to 1:21) it seems like the engines in the fuselage produce high-speed air that is diverted to the edge of the fan duct. This air then drives the fans at sufficiently high speed to create a lifting force from the motion of the fan rotor. Looking at the wing structure in these videos and at the exhaust routing, I don't see how else to get the vertical lift another way either. | |
| Apr 28, 2017 at 17:50 | comment | added | mins | I'm not sure ducted fans were used in the XV-5A Vertifan. These are lift fans driven by gas from the engine (which is not on the wings) and using the circumference of the fan as a turbine. The duct is actually the turbine annular duct, I don't know if it is also used as a fan duct. | |
| May 10, 2016 at 15:32 | comment | added | Daniel Caoili | So what do you think about adding only guide vanes without the duct? | |
| May 10, 2016 at 9:34 | comment | added | Dan Hulme | The Edgley Optica is a good example of a flying civilian ducted-fan aircraft. | |
| May 10, 2016 at 1:51 | comment | added | Marius | Got it--thanks! | |
| May 10, 2016 at 1:48 | history | edited | Marius | CC BY-SA 3.0 |
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| May 9, 2016 at 14:17 | comment | added | FreeMan | Please source your image, as well. It's not clear if it comes from the thesis paper, or somewhere else. | |
| May 9, 2016 at 14:17 | history | edited | FreeMan | CC BY-SA 3.0 |
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| May 8, 2016 at 4:00 | history | answered | Marius | CC BY-SA 3.0 |
