Re: L1011 engine No 2

Date:         17 Oct 99 23:29:46 
From:         Trevor Fenn <>
References:   1 2
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David Lednicer wrote:
> The fairing you are looking at is called a "Frisbee Fairing", named
> after its developer.  The fairing is designed to eliminate a flow
> separation that occured in that area and in doing so, it reduces the
> noise in the aft cabin.  It was originally only fitted to L1011-500s.
>         The separation that it eliminates is caused by the relatively thick
> boundary layer on the fuselage encountering a region of increasing
> (adverse) pressure in front of the "pylon" below the #2 engine inlet.
> Without the fairing, the adverse pressure gradient would be too steep
> for the boundary layer to stay attached and it would separate, forming a
> necklace vortex around the "pylon".  The fairing makes the gradient less
> steep and eliminates the separation and associated vortex.

Sounds good but if I recall correctly it is a Frakes Fairing.

Trevor Fenn