Turbine engine with hydrogen-compatible fuel-air mixing assembly including defined orifice geometry and flow path

A turbine engine comprising:

• an engine core comprising at least a compressor section and a combustion section in serial flow arrangement, wherein the combustion section comprises at least one fuel-air mixing assembly comprising:
• a center body;
• an outer wall spaced from and in annular arrangement about the center body;
• air passage defined between the center body and the outer wall, the air passage including a constant cross-sectional area portion and exhausting at an outlet;
• a first fuel orifice extending through the outer wall and exhausting to the air passage;
• and
• an aperture extending through the outer wall and fluidly coupled to the air passage, aperture-to-orifice distance is defined as a distance between the aperture and the first fuel orifice, and wherein the aperture-to-orifice distance is between or equal to 10%-95% of a length of the center body,
• wherein the constant cross-sectional area portion is located downstream of the first fuel orifice and is configured to maintain a velocity of a fuel-air mixture sufficient to suppress flashback when the at least one fuel-air mixing assembly operates with a hydrogen fuel.

A turbine engine comprising:

• an engine core comprising at least a compressor section and a combustion section in serial flow arrangement, wherein the combustion section comprises at least one fuel-air mixing assembly comprising:
• a center body;
• an outer wall spaced from and in annular arrangement about the center body;
• air passage defined between the center body and the outer wall, the air passage including a constant cross-sectional area portion and exhausting at an outlet;
• a first fuel orifice extending through the outer wall and exhausting to the air passage;
• and
• an aperture extending through the outer wall and fluidly coupled to the air passage, wherein the air passage includes a constant cross-sectional area extending forward from the outlet and a converging cross-sectional area extending from the aperture to the constant cross-sectional area,
• wherein the constant cross-sectional area portion is located downstream of the first fuel orifice and is configured to maintain a velocity of a fuel-air mixture sufficient to suppress flashback when the at least one fuel-air mixing assembly operates with a hydrogen fuel.