8
$\begingroup$

I have a model airplane whose wings I would like to fit with light strips top and bottom. These light strips would be across a significant portion of the wing's span. Without extensive study (wind tunnel, etc.) is it possible to say where I should put these light strips chord-wise so as to minimally impact lift, stability, etc? Here's an example of such a lit-up airplane:

In this case, it appears the lights are placed by the manufacturer around the half chord point, but I don't know if that's more the exception or the rule.

BTW, I'm planning on trying to bury the strips in the wing, not just sit them on top. But I may not do a perfect job, so I want to have minimal impact.

Improve this question
$\endgroup$
2
  • $\begingroup$ Excellent video. Mount the lights inside the wing and cover with clear Monokote. $\endgroup$
    – Robert DiGiovanni
    Sep 12 at 21:51
  • $\begingroup$ @RobertDiGiovanni That was basically my thought. Of course, the top and bottom sides want to be visually different so I can't take that too far. $\endgroup$
    – fool4jesus
    Sep 13 at 11:19

1 Answer 1

Reset to default
14
$\begingroup$

Generally, the farther aft a small obstacle is, the less turbulence and drag it makes, because farther aft the boundary layer is more likely to be already turbulent.

However, if the obstacle is heavy, placing it aft might require extra nose weight to restore the location of the CG. That extra weight might be undesirable.

Also, disturbing the wing's upper surface is more likely to encourage a separation bubble and stall, than disturbing the lower surface (where positive pressure will reattach the airflow, albeit with some drag). Of course, this doesn't matter for an aerobat that often flies inverted.

Practically, for this airspeed and Reynolds number and power-to-weight ratio, it doesn't matter. You could even mount the LED strip right on the leading edge, with a ghastly mess of tape and hot-melt glue, and claim that you've added a turbulator strip to make the stall break more manageable.

Improve this answer
$\endgroup$
2

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .