DefinePK

Abstract

The rapid increase in global energy needs has generated a considerable attention to the generation of energy from renewable energy sources. Hydrokinetic turbines is a vertical axis type water turbine that is very simple and appropriate for remote areas. A hydrokinetic turbine has a good performance and is capable of producing considerable torque at high water speeds. The activity in this study is to model a small hydrokinetic turbine simulated with a CFD software, by varying the position of the turbine runner in each 5°runner rotation so as to obtain the pressure value between the two blades as an indicator of the force magnitude occurring or generated. In a previous study a vertical axis hydrokinetic turbine model was tested in the laboratory compared to the results with a simulated test with CFD. The laboratory test turbine performance result has a same or similar performance result calculate from the CFD simulation. From the simulation results it is seen that there are only two blades being pushed by the water flow. It is suggested to add a steering blade on the turbine output area, in order to increase the blade number to be pushed by the water flow rate. By attaching a steering blade on the output part of the turbine, the water prevents from leaving the turbine and deflected to push another blade, resulting in more water-boosting blades. To ensure that this step will produce a better result, the first step to do is simulating the turbine with a steering blade. The results obtained in every 5° runner position is that there is an increase in water pressure between the two blades. This phenomenon shows that there is an increase in the turbine performance. One of the simulation results is, at a runner position a = 20°, the water pressure between blade two and blade three rises from 8.15e + 009 Pa in the turbine without a steering blade, to 4.69e + 010 Pa in the turbine with a steering blade. While the water pressure between blade five and the blade six, that had a very low water pressure of 4.86e + 008 Pa, rose to 2.30e + 010 Pa, after being given a steering blade. This shows that the steering blade addition would give an additional water boost to some blades.