To solve the high temperature problem of new ratchet ultra-compact combustor

a full-coverage film cooling method was adopted. Based on the experiment and simulation of KJ-66 micro gas turbine

the original combustor was replaced with a ratchet ultra-compact combustor after scaling optimization. Then

according to the high temperature wall of the slope of the sudden expansion section and the inner ring in the secondary combustion zone

the influences of different arrangement modes

hole inclination angles and expansion film holes on the film cooling effect under actual combustion conditions were compared. The results showed that the film coverage of the cylindrical film holes on the slope of the sudden expansion section was not ideal

the comprehensive film cooling effect was not good

and different arrangements and hole inclination angles had little influence on the film cooling effect. The air film adhesion and cooling effects of the slope were greatly improved by expansion film holes. In the expansion film holes with 45° hole inclination angle and 0.6 mm outlet diameter

the comprehensive cooling effect produced by blowing off the high temperature flame surface and overlaying the air film was the best. Under the influence of the mainstream high centrifugal force field

the downstream of the secondary combustion zone could also obtain better adhesion effects of film when the blowing ratio was larger. The influence of the arrangements on the film cooling effects in the secondary combustion zone was more obvious than that of the hole inclination angles. On the whole

the full-coverage film cooling has good cooling effects on the wall of the ratchet ultra-compact combustor under actual combustion conditions. Expansion film holes can effectively improve the film cooling effects.