A fluid flow actuated tool including a housing, a tool and an actuating mechanism. The housing includes a housing interior. The housing interior receives a flow of fluid. The actuating mechanism includes a fluid wheel structure. The fluid wheel structure is connected to the tool. At least a portion of the fluid wheel structure is arranged in the flow of fluid for rotating the fluid wheel structure. The tool is actuated based on rotation of the fluid wheel structure.

A fluid flow actuated tool including a housing, a tool and an actuating mechanism. The housing includes a housing interior. The housing interior receives a flow of fluid. The actuating mechanism includes a fluid wheel structure. The fluid wheel structure is connected to the tool. At least a portion of the fluid wheel structure is arranged in the flow of fluid for rotating the fluid wheel structure. The tool is actuated based on rotation of the fluid wheel structure.

A turbine that includes a runner and a variable nozzle. The runner is configured to rotate about an axis of rotation. The variable nozzle is configured to produce a sheet flow when fluid passes through the variable nozzle toward the runner. The sheet flow has a circumferential length at an exit of the variable nozzle that is greater than a flow width at the exit of the variable nozzle. The flow width is adjustable. In other configurations, the sheet flow may be planar, conical, or cylindrical.