An axial turbine is a turbine in which the flow of the working fluid is parallel to the shaft, as opposed to radial turbines, where the fluid runs around a shaft, as in a watermill. An axial turbine has similar construction as an axial compressor, but it operates in the reverse, converting flow of the fluid into rotating mechanical energy. An axial turbine is a turbine in which the flow of the working fluid is parallel to the shaft, as opposed to radial turbines, where the fluid runs around a shaft, as in a watermill. An axial turbine has similar construction as an axial compressor, but it operates in the reverse, converting flow of the fluid into rotating mechanical energy.