Virtual and Experimental Testing of Novel Screw Hydro Turbine for Micro-Grid and Maritime Applications

In recent decades the design of micro turbines is gaining momentum due to increasing interest in reducing dependence on fossil fuels and towards the developent of self-sustained residential electricity production. Besides powering houses, micro turbines can also be implemented as power sources for harnessing the energy of sea currents in maritime application, providing as power source with more stable behavior than wind or sun. In this work, novel type of hydro turbine is investigated numerically and experimentally and applied in two scenarios: (i) on a larger scale to produce 10 kW of power from waste water stream and (ii) on a smaller scale to produce power from sea current to recharge batteries. Numerical simulations are conducted using state of the art computational fluid dynamics modelling employing sliding mesh methodology. The simulation results provide detailed insight in the flow details and accurate predictions of the produced power for a range of flow velocities and generator RPMs. The CFD analysis is also implemented as a tool to design a small scale hydro turbine for recharging the batteries of a small sea boat. The prototype was produced using 3D printed PLA filament which is biocompatible and relatively cheap material, while the turbine design is fish friendly. The prototype micro turbine demonstrated that the batteries can be recharged even when the sea current is below 2 kn which is very difficult to achieve with other micro turbine designs and enables recharging of the batteries also when the boat is in the dock. This novel micro turbine design is relatively inexpensive and can be implemented for producing renewable energy from various sources which were so far considered economically non feasible.