Numerical analysis of on the effects of Hydrokinetic turbine presence in flow structure of a compound open-channel

In the recent years, due to the hydropower plants environmental problems, hydrokinetic turbine usages has been increased. Using such turbines in rivers modify natural flow-field. In previous studies, impacts of turbine on the flow-field just only in rectangular open-channel is studied. In this work, the effects of hydrokinetic turbine in a straight compound channel has been numerically studied using Fluent extension of Ansys 16. To simulate the turbine rotation, Moving Reference Frame (MRF) method has been implemented. Results showed that due to the turbine presence, natural flow structure and pressure distribution has been drastically changed. Indeed, instead of compound channel secondary currents, a strong secondary flow from the right back to left bank (where the turbine installed) is formed. Also results show that a wake region behind the turbine and regions with high velocity around turbine can be notified. In low velocity inlet, the flow field is intact and natural condition is preserved, while high inlet velocity causes drastic changes. Therefore, it can be concluded that in this situation, considering low effects of turbine presence in flow structure the inlet velocity should be low, while in this condition, the efficiency due to the low velocity would be not be impressive.