A combustor assembly for a gas turbine engine includes an inner liner, an outer liner, and a combustor dome. The inner liner, outer liner, and combustor dome together define at least in part a combustion chamber having an annulus height. Additionally, the combustor assembly includes a fuel-air injector hardware assembly positioned at least partially within an opening of the combustor dome. The fuel-air injector hardware assembly includes a heat shield located at least partially within the combustion chamber, the heat shield defining an outer diameter. A ratio of the annulus height of the combustion chamber to the outer diameter of the heat shield may be at least about 1.5:1.