Front Electric Sustainer

On Mon, 19 Apr 2010 06:23:36 -0700, Dave Nadler wrote:

http://antwrp.gsfc.nasa.gov/apod/ap100419.html

True enough: the ASW's smaller multi-blade pros disk makes the problem
proportionately worse while about the only extra downside on the Antares
is interference drag between the pylon legs.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Apr 19, 10:28*am, Martin Gregorie
wrote:
On Mon, 19 Apr 2010 06:23:36 -0700, Dave Nadler wrote:
... while about the only extra downside on the Antares
is interference drag between the pylon legs.

Actually I forgot the usual pusher-problem:
the wake from the pylon hits the prop.
I suspect (not expert enough to know)
the wake interference makes most of the
(minimal) noise you hear from an Antares.
Tractor would be more efficient but
didn't fit in the optimal fuselage shape.

Any aero experts care to comment ?

See ya, Dave "YO electric"

On Mon, 19 Apr 2010 11:48:46 -0700, Dave Nadler wrote:

Actually I forgot the usual pusher-problem: the wake from the pylon hits
the prop. I suspect (not expert enough to know) the wake interference
makes most of the (minimal) noise you hear from an Antares. Tractor
would be more efficient but
didn't fit in the optimal fuselage shape.

I don't think it can be very significant in prop efficiency terms of
Martin Hepperle would have picked up on it and insisted on using a single
blade pylon.

I do have a comment on noise: the day I mentioned when the ASW22 and the
Antares launched at a fairly similar time was a calm, fairly quiet day
apart from the usual sounds when a grid is being launched: all the tugs
on the field had 4 blade props and silencers. I happened to be standing
about 50m to one side of the runway and about 100 m in front of the grid
when the Antares took off. The only sound I remember hearing from it was
a sort of puttering sound which was almost certainly from the prop tips.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |