A combustor for a turbine engine is provided, the combustor includes an outer liner, an inner liner and a dome that together define a combustion chamber; a diffuser positioned upstream of the combustion chamber, the diffuser being configured to receive air flow from a compressor section and to provide a flow of compressed air to the combustion chamber; and an outer cowl and an inner cowl located upstream of the combustion chamber, the outer cowl and the inner cowl being configured to direct a portion of air flow from the diffuser to the combustion chamber. The diffuser is configured to output air flow having an amount of air pressure maximized at a center of the air flow so as to optimize total air pressure fed to the combustion chamber through the dome.