An airfoil blade assembly comprising: a blade (30, 30') extending in a radial direction from a root towards a tip, the blade including a lift generating section with a first profiled body defined between a pressure surface and a suction surface, the first profiled body extending from a first leading edge to a first trailing edge with a first chord extending from the first leading edge to the first trailing edge and being perpendicular to the radial direction; a plurality of flow deflectors (50, 50') extending along at least one of the pressure surface and the suction surface within the lift generating section of the blade at positions spaced apart from the first leading edge of the blade (30, 30') and proximate to the first trailing edge of the blade (30, 30'), the plurality of flow deflectors (50, 50') defining a second profiled body extending between a second leading edge and a second trailing edge with a second chord extending between the second leading edge and the second trailing edge, the second profiled body defining an outer surface facing away from respective pressure surface or suction surface along which the plurality of flow deflectors (50, 50') extend; wherein the second chord extending between the second leading edge and the second trailing edge of each of the plurality of flow deflectors (50, 50') is proportional to the first chord extending from the first leading edge to the first trailing edge of the blade at the location of each of the plurality of flow deflectors (50, 50') along at least one of the pressure surface and the suction surface, wherein the second chord length of each of the plurality of flow deflectors (50, 50') is sized to be between 1/8 and 1/2 of the first chord length of the blade at the location of each of the plurality of flow deflectors (50, 50'); and wherein the plurality of flow deflectors (50, 50') are positioned along a length of the blade (30, 30') so that a radial component of velocity of an incoming airflow is redirected to produce an additional amount of torque on a rotor, thereby increasing overall power produced by a turbine incorporating the airfoil blade assembly. a blade (30, 30') extending in a radial direction from a root towards a tip, the blade including a lift generating section with a first profiled body defined between a pressure surface and a suction surface, the first profiled body extending from a first leading edge to a first trailing edge with a first chord extending from the first leading edge to the first trailing edge and being perpendicular to the radial direction; a plurality of flow deflectors (50, 50') extending along at least one of the pressure surface and the suction surface within the lift generating section of the blade at positions spaced apart from the first leading edge of the blade (30, 30') and proximate to the first trailing edge of the blade (30, 30'), the plurality of flow deflectors (50, 50') defining a second profiled body extending between a second leading edge and a second trailing edge with a second chord extending between the second leading edge and the second trailing edge, the second profiled body defining an outer surface facing away from respective pressure surface or suction surface along which the plurality of flow deflectors (50, 50') extend; wherein the second chord extending between the second leading edge and the second trailing edge of each of the plurality of flow deflectors (50, 50') is proportional to the first chord extending from the first leading edge to the first trailing edge of the blade at the location of each of the plurality of flow deflectors (50, 50') along at least one of the pressure surface and the suction surface, wherein the second chord length of each of the plurality of flow deflectors (50, 50') is sized to be between 1/8 and 1/2 of the first chord length of the blade at the location of each of the plurality of flow deflectors (50, 50'); and wherein the plurality of flow deflectors (50, 50') are positioned along a length of the blade (30, 30') so that a radial component of velocity of an incoming airflow is redirected to produce an additional amount of torque on a rotor, thereby increasing overall power produced by a turbine incorporating the airfoil blade assembly.