I thought the tube should have a slight expanding taper/venturi so when
the hot exhaust met the cool air and mixed in the tube they would expand.
That is correct,
On an 85LbF Lockwood pulse jet powered GoKart, we used an augmentor with a
bellmouth inlet and a slight tapped exhaust cone,<5 degrees.
While I never measured the thrust increase the owners claimed double digit
augmentation.
K
On Fri, Feb 12, 2021 at 12:27 PM Peter Fairbrother <peter@xxxxxxxxxx> wrote:
On 12/02/2021 14:07, Nels Anderson wrote:
On 2/11/21 4:59 PM, Henry Spencer wrote:
On Thu, 11 Feb 2021, Norman Yarvin wrote:
If ambient air is mixed into the exhaust as a working fluid, then it
will expand, conceivably generating additional thrust.
Still, to be realized, that thrust would have to actually exert
pressure somewhere, and the walls of that aluminum tube are parallel
to the flow, so that couldn't be where. (The bell-shaped portion is
the intake, not the exhaust.)
Other things being equal -- a big assumption -- suction in a
forward-facing intake bell is just as good as pressure in an
aft-facing nozzle bell.
Or how about simply increasing pressure at the original (w/o
augmentation tube) nozzle exit.
I thought the tube should have a slight expanding taper/venturi so when
the hot exhaust met the cool air and mixed in the tube they would expand.
Never tried it though.
Peter Fairbrother