>Is there an optimum spoiler size - say percent of chord? >Working on a low aspect ratio 2M with a root chord of 15.375". >Center panel (where the spoiler will be) is flat and 20.5" span.
I'm not sure what you mean by "optimum". The bigger the spoiler and the farther forward it is, the more sink rate you get. As you probably know, I favor putting the spoiler very far aft where it can't hurt the airfoil significantly even with an imperfect fit. Such a spoiler should be very big to compensate for loss of effectiveness. For your big wing area, I'd make the spoiler 2.0 to 2.5" wide, and the full 20.5" panel span for simplicity. Putting the spoiler's TE at 65% chord will place the spoiler over one of the AG3x airfoil's flat facets, so the spoiler wants to be flat and hence will be easier to make. Make sure you have at least 10 deg of additional up-elevator travel to compensate for the spoiler's upwash via mixing. - Mark RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
