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Which side of an obliquely swept wing will create more lift? By "obliquely swept wing" I mean this:

enter image description here

This answer states that the overall lift will decrease due to an effective decrease in wing area. That answer was focusing on an aircraft in a sideslip, but I'm fairly sure the overall effect will be the same as in this picture.

I read through some of this paper, and in section 2.2.2 (AKA page 16) it says:

A well-known effect of wing sweep is the variation of induced downwash along the span from the trailing wake that produces an additional lift distribution characterized by increased loading on the aft wing and reduced additional lift on the forward wing. For a wing with no twist or bend, this results in a significant rolling moment, tending to roll the forward wing downward.

Note: The use of the term "wing sweep" in this excerpt is being used to describe a scenario like the picture above. Not what you would usually think of wing sweep as.

It states that the forward wing will tend to roll downward (so the right wing in the picture above would roll downwards). Why is this?

I can't see anything that would differentiate the aft wing vs. the forward wing in terms of aerodynamics, so what am I missing?

This paper provided by @mins explains a lot, but I am not 100% sure on this. If this was considering a tapered wing like the one above, it would make total sense that the 2 sides have different lift.

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  • $\begingroup$ Compare swept to unswept, and unswept to forward-swept. Those affect much more than just lift, though, and their differences vary with speed and AoA, so your answer may turn out to be messy. $\endgroup$
    – Camille Goudeseune
    Commented Oct 18 at 22:15
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    $\begingroup$ This paper helps understanding the rolling moment due to the difference in lift is one among many other moments and side forces. $\endgroup$
    – mins
    Commented Oct 19 at 10:03
  • $\begingroup$ @mins Thanks for that paper, it almost completely answered my question. So, it says the spanwise flow is the reason for the asymmetrical lift distribution. How does the flow traveling spanwise change the lift? I do have a theory, but not sure about it. $\endgroup$
    – Wyatt
    Commented Oct 19 at 16:28
  • $\begingroup$ The spanwise component is not accelerated, it creates no lift (but the article focuses on where is the lift concentrated, i.e. near the leading edge and the tip for the left wing). You may be interested in this book which is the story of the oblique wing. $\endgroup$
    – mins
    Commented Oct 19 at 17:17
  • $\begingroup$ @mins Ah okay, thanks. Also, in the same paper it describes that there is an increase in wave drag on the upwind wing (at supersonic speeds of course). Both sides of the oblique wing are symmetrical, so do you have any idea why this is the case? $\endgroup$
    – Wyatt
    Commented Oct 19 at 22:36

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