The recent technological developments being applied to Tesla like turbines for converting fluid energy into mechanical （axis） energy often lead to non-frequently used models. Given a disk shaped machine rotating aro...The recent technological developments being applied to Tesla like turbines for converting fluid energy into mechanical （axis） energy often lead to non-frequently used models. Given a disk shaped machine rotating around its own symmetry axis, part of the machine energy is transferred to the fluid itself, pushing it to the disk periphery. This way the farther the exhaust orifice is from the disk outside contour, the larger will be the pressure loss experienced by the system. This work studies the overall energy balance and momentum exchange between fluid and machine. Simple calculation shows that for total pressure gradients above two bar the machines become inefficient for having tangential velocity whose intensity is 50% higher than the intensity of the jet velocity prior to the interaction. For values of the pressure gradient above 5.7 bar, the machine peripheral velocity is equal to the incident jet velocity. In this case it is not possible to deliver power under permanent regime. Finally it is shown that when the feeding pressure of an impulse turbine is enough for more than one stage, then one should use this option to obtain thermal efficiencies similar to those of reaction machines. The jet of fluid to move a Tesla like turbine should enter the unit as close as possible to the direction tangential to the movement, （i.e., normal to the radius at the considered position）. This fluid should leave the machine right after interacting with it. Any permanence of the fluid after transferring its momentum to the machine can be extremely prejudicial to the system behavior.展开更多
文摘The recent technological developments being applied to Tesla like turbines for converting fluid energy into mechanical （axis） energy often lead to non-frequently used models. Given a disk shaped machine rotating around its own symmetry axis, part of the machine energy is transferred to the fluid itself, pushing it to the disk periphery. This way the farther the exhaust orifice is from the disk outside contour, the larger will be the pressure loss experienced by the system. This work studies the overall energy balance and momentum exchange between fluid and machine. Simple calculation shows that for total pressure gradients above two bar the machines become inefficient for having tangential velocity whose intensity is 50% higher than the intensity of the jet velocity prior to the interaction. For values of the pressure gradient above 5.7 bar, the machine peripheral velocity is equal to the incident jet velocity. In this case it is not possible to deliver power under permanent regime. Finally it is shown that when the feeding pressure of an impulse turbine is enough for more than one stage, then one should use this option to obtain thermal efficiencies similar to those of reaction machines. The jet of fluid to move a Tesla like turbine should enter the unit as close as possible to the direction tangential to the movement, （i.e., normal to the radius at the considered position）. This fluid should leave the machine right after interacting with it. Any permanence of the fluid after transferring its momentum to the machine can be extremely prejudicial to the system behavior.
