Re: PSV Tailpipe, 45 Degree Cut?

Tony Paulin sent:

> Dr. Hans Bos (author of BOS Fluids) added the following, which I thought
> might be useful, and so wanted to pass along:

> 2) The lateral load component at the tail pipe exit is equal to
> the normal thrust force multiplied by the sine of one half of the bevel
> angle.
> 4) Beveled ends break the flow symmetry at the exit, disturbing
> the periodic shedding of stable torus type vortices that contribute to
> noise strength. Rotational symmetry in the diamond shaped shock
> wave/expansion pattern downstream of the tail pipe, in combination with
> the convection of vortices is considered the origin of the screeching
> noise in jet exhausts.

So if a bevel is placed on the outlet of a jet engine could it simultaneously reduce noise and re-direct thrust advantageously?

That's probably a dumb question.

Paul Received on Thu Feb 15 23:17:00 2007