Heres a really easy question I don't know...
01-03-2009 | 08:28 PM
#26
RE: Heres a really easy question I don't know...
Thanks Tam. Your holes are a good solution. I haven't used them yet but may in the future.
Note that sketch is no way near scale so the dimensions and pipe distance aren't accurate.
Note that sketch is no way near scale so the dimensions and pipe distance aren't accurate.
01-03-2009 | 09:37 PM
#28
Thread Starter
Joined: May 2006
Posts: 1,644
Likes: 0
Received 0 Likes
on
0 Posts
From: East Providence, RI
RE: Heres a really easy question I don't know...
ORIGINAL: causeitflies
My explanation for the holes:
The high speed/low pressure exhaust flowing into the pipe draws a huge amount of air by venturi effect. This air cools the pipe and can through expansion increase thrust (with the proper design!!).
With no by-pass the engine gets the air it needs and the pipe gets the air it needs.
With some by-passes the restriction doesn't allow the pipe to get enough air and/or the engine and pipe are competing for the same air. This is especially true at low speeds and high throttle where very little air is rammed in the intakes. Performance of the engine will suffer.
Cutting holes in the aft of the by-pass allows extra air to be sucked into the pipe so it and the engine get all the air they need.
Some sketches below may help to explain:
My explanation for the holes:
The high speed/low pressure exhaust flowing into the pipe draws a huge amount of air by venturi effect. This air cools the pipe and can through expansion increase thrust (with the proper design!!).
With no by-pass the engine gets the air it needs and the pipe gets the air it needs.
With some by-passes the restriction doesn't allow the pipe to get enough air and/or the engine and pipe are competing for the same air. This is especially true at low speeds and high throttle where very little air is rammed in the intakes. Performance of the engine will suffer.
Cutting holes in the aft of the by-pass allows extra air to be sucked into the pipe so it and the engine get all the air they need.
Some sketches below may help to explain:
So, Apparently my SM F-16 ARF does not include a full bypass. It comes with a BP which at best, ends just before the turbine intake. Ill see what I can do with it and post pics.
Thank you so much, Pete
