such that a balanced flow path results from the mixing of the two flow paths furthermore due to the axial configuration of injectors 256 the second flow leg 170 does not create an air darn which restricts the flow of first flow leg 168 as a result the axial configuration of injectors 256 facilitates increasing dynamic pressure recovery within the resultant flow path by balancing pressure loss and velocity within combustion liner cooling passage 154 injectors 256 and annular gap 304 facilitate substantially uniform heat transfer between combustor liner 350 and the cooling air moreover grooves 358 of combustor liner surface 356 facilitate enhancing the heat transfer between cooling air and combustor liner 350 specifically grooves 358 facilitate circumferentially distributing cooling air from injectors 256 and facilitate creating a uniform heat transfer coefficient distribution across the length and circumference of combustor liner 350 in addition grooves 358 facilitate allowing high velocity cooling air to facilitate improving heat transfer the above described apparatus and methods facilitate providing constant heat transfer between cooling air and a combustor liner while maintaining an overall pressure of the gas turbine engine specifically the injectors facilitate reducing pressure losses by injecting the cooling air of the second flow leg axially such that dynamic pressure recovery is increased between the first and second flow leg furthermore.