Most annular combustors have airflow the flows in a linear path through the combustor. A combination of swirlers and air dilution holes forming an insluting jacket of cooling air around the inner surface of the combustor to prevent it melting.
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. I have been searching for months and can't come up with a definitive answer.
The photo below is not a PT6 but is the best I could find for illustration.
