A fuel nozzle for use with a turbine engine, said fuel nozzle comprising: a housing adapted for coupling to a combustor liner defining a combustion chamber, said housing comprising an endwall that at least partially defines the combustion chamber; and a plurality of mixing tubes extending through said housing for channeling a fuel to the combustion chamber, each mixing tube of said plurality of mixing tubes comprising an inner surface extending between an inlet portion and an outlet portion, a fuel aperture extending through said inner surface configured to channel a flow of fuel to said mixing tube, said outlet portion oriented adjacent said housing endwall, at least one of said plurality of mixing tubes comprising: a plurality of projections wherein each projection extends radially between a radially inner surface and a radially outer surface, and axially between a base portion and a tip surface, said tip surface extending between sidewalls and and between said inner surface and outer surface, adjacent projections being spaced a circumferential distance apart such that a groove is defined between each pair of circumferentially-apart projections to facilitate enhanced mixing of fuel in the combustion chamber; and wherein each projection of said plurality of projections comprises one of the following: i) the first sidewall and the second sidewall are each orientated to converge from outer surface to inner surface such that the tip surface has a trapezoidal shape; ii) the tip surface extends obliquely with respect to said mixing tube inner surface towards said mixing tube outer surface; iii) the tip surface extends along an arcuate shape from said mixing tube inner surface toward said mixing tube outer surface. a housing adapted for coupling to a combustor liner defining a combustion chamber, said housing comprising an endwall that at least partially defines the combustion chamber; and a plurality of mixing tubes extending through said housing for channeling a fuel to the combustion chamber, each mixing tube of said plurality of mixing tubes comprising an inner surface extending between an inlet portion and an outlet portion, a fuel aperture extending through said inner surface configured to channel a flow of fuel to said mixing tube, said outlet portion oriented adjacent said housing endwall, at least one of said plurality of mixing tubes comprising: a plurality of projections wherein each projection extends radially between a radially inner surface and a radially outer surface, and axially between a base portion and a tip surface, said tip surface extending between sidewalls and and between said inner surface and outer surface, adjacent projections being spaced a circumferential distance apart such that a groove is defined between each pair of circumferentially-apart projections to facilitate enhanced mixing of fuel in the combustion chamber; and wherein each projection of said plurality of projections comprises one of the following: i) the first sidewall and the second sidewall are each orientated to converge from outer surface to inner surface such that the tip surface has a trapezoidal shape; ii) the tip surface extends obliquely with respect to said mixing tube inner surface towards said mixing tube outer surface; iii) the tip surface extends along an arcuate shape from said mixing tube inner surface toward said mixing tube outer surface. i) the first sidewall and the second sidewall are each orientated to converge from outer surface to inner surface such that the tip surface has a trapezoidal shape; ii) the tip surface extends obliquely with respect to said mixing tube inner surface towards said mixing tube outer surface; iii) the tip surface extends along an arcuate shape from said mixing tube inner surface toward said mixing tube outer surface.