PPRuNe Forums - View Single Post - PT-6 Annular Combustor
View Single Post
Old 22nd May 2021, 16:36
  #8 (permalink)  
pattern_is_full
 
Join Date: Jan 2008
Location: Denver
Posts: 1,080
Originally Posted by Ozgrade3 View Post
So how does the PT-6 combustor with its side entry of air, form the flame vortex that keeps the hottest gases in the centre of the combustor and the cooling jacket of air attached to the inner surface of the combustor.
This what you actually asked - how does the PT6 keep the combustor-liner surface relatively cool compared to the hottest gasses in the center.

A flame vortex is one way of doing that. It is not the only way.

The PT6 surrounds the combustion chamber liner with colder air (like putting a drink into a ice bucket). Doesn't need a vortex for cooling that surface.

Now, some swirling of the air is important for mixing the fuel and air and getting the most efficent burn. The PT6 combustor-chamber liner does this by putting shallow deflection "cooling rings" just inside the side air intake holes, so that air does not actually enter in a straight line, but is deflected into swirls after it passes through the holes. This is one of the things simplfied schematics will not show correctly in detail.

See diagram on page 16 of this PT6 Training Manual: http://www.mautone.eng.br/apostilas/...g%20Manual.pdf

Once combustion has been achieved, the curved duct that reverses the flow forwards to the turbines (and encounters the hottest gas) is ceramic-lined for heat resistance.
pattern_is_full is online now