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How does distributed propulsion work in a pusher configuration?

In a tractor configuration, the wing benefits from a portion of the prop wash flowing over the wing and producing extra lift ( I stand to be corrected).

In a pusher configuration, there is no prop wash flowing over the wing.

So how does distributed propulsion created extra lift and/or thrust in a pusher configuration?

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The wings don't benefit all that much. Look at a small airplane from head on - how much wing is directly behind the prop?

My airplane for example, the prop is 86" diameter. The fuselage is 46" wide - so 20" of wing on either side is behind the prop. The wing itself is 35'6", or 426", so less than 1/10" is in direct prop airflow.

The prop pulls the plane forward, airflow over/under the wing then creates the lift. enter image description here enter image description here

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    $\begingroup$ I suppose the question is about this: en.wikipedia.org/wiki/Distributed_propulsion $\endgroup$ – ymb1 Jan 16 at 15:32
  • $\begingroup$ This still doesn't answer the question though. Also, multiple small shrouded props would increase efficiency greatly. See pic: commons.wikimedia.org/wiki/…D60_Symposium-Defense_Advanced_Research_Projects_Agency-_DSC05528.jpg $\endgroup$ – Fred Jan 16 at 17:03
  • $\begingroup$ Air from the prop over the wing doesn't generate the lift that makes and airplane go up - it it did, we could all levitate off the runway. Air from the prop creates forward speed, the airflow from that speed is what creates lift. If prop wash was that good at creating lift, then why do the airlines all have their jet engines, which create tons of airflow, blow over the wing to reduce take off distances (assuming they could make wings out of material that could withstand the heat, and that fuel stored in wing tanks wouldn't be negatively affected)? $\endgroup$ – CrossRoads Jan 16 at 18:05
  • $\begingroup$ @Fred, the 2nd link is incomplete and opens a "does not exist" page. ymb1, the D60 vehicle looks more like a distributed helicopter, altho there might be conventional wing lift created once it gets moving forward. It does not provide airflow to the front of the wing as an engine in tractor configuration does. $\endgroup$ – CrossRoads Jan 16 at 18:18
  • $\begingroup$ Here is a link to a mid wing distributed propulsion aircraft: commons.wikimedia.org/wiki/…D60_Symposium-Defense_Advanced_Research_Projects_Agency-_DSC05528.jpg $\endgroup$ – Fred Jan 16 at 19:00
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Although the benefit is marginal, the exhaust output of a turbo shaft engine (aka a turboprop engine) is usually vectored to the rear of an airplane. This does add to the forward thrust of the plane.

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