International Journal of Advanced Engineering Research and Science (IJAERS) [Vol-5, Issue-9, Sept- 2018] https://dx.doi.org/10.22161/ijaers.5.9.32 ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 281 Tidal Speed Simulation of Seawater against Torque (τ) and Power (P) Produced by the Darrieus Turbine Type H Titik Nurhayati 1 , Agus Margiantono 2 1 Department of Electrical Enginering university of Semarang Email: titiknur@usm.ac.id 2 Department of Electrical Enginering university of Semarang Email: agus_margiantono_mt@yahoo.com Abstract —The depletion of fossil energy reserves and environmental issues currently play an important role in developing the concept of renewable energy, so that the search for new renewable energy is carried out very intensively. One type of renewable new energy that has the potential to be developed in Indonesia is the energy of river estuary flows, considering that Indonesia is an archipelagic country.This study, discusses renewable energy derived from the river mouth of the Bedono village of Demak Regency. The results of the observations that have been made, the tidal currents of the river which occur 2 times in 24 hours with an average current velocity at 0.953m/s. The biggest current velocity at 14.00-16.00 is 2.5 m/s and the lowest is 0.5 m/s at 06.00- 08.00. Using the Computating Fluid Dynamic (CFD) model simulation and the Darrieus Type H turbine, with specifications; Diameter 1m, chord length 0.1m, turbine length 1 m, number of blade 3 and type of blade Hydrofill: NACA 0018 obtained the greatest power occurs at 14.00-16.00 at 8007.813Watt with a torque of 3540.470Nm and the lowest power of 83.726Watt with torque amounting to 14,663Nm at 04.00-06.00. Keywords— Energy, Computating Fluid Dynamic (CFD), Darrieus Turbine Type H, Tidal, Model Simulation. I. INTRODUCTION The depletion of fossil energy reserves and environmental issues currently play an important role in developing the concept of renewable energy, so that the search for new renewable energy is carried out very intensively. One type of renewable new energy that has the potential to be developed in Indonesia is the energy of river estuary flows, considering that Indonesia is an archipelagic country. From the observation, the flow of the river mouth in the Bedono village of Demak Regency occurred 2 times in 24 hours with an average current speed of 0.953m / s potentially used as a power plant. II. LITERATURE REVIEW Darrieus Turbine Darrieus turbine is a type of turbine that was developed by a French aeronautical engineer named Georges Jean Marie Darrieus in 1931. This darrieus turbine has advantages such as not taking too much into the flow direction because of its symmetrical shape, gravity pressure is not able to return to the blade shape, able to operate at low head and speed, while its weakness is the inability to self-starting, and high vibration. The working principle of the Darrieus turbine is due to the speed of the water flow which causes the blade to rotate with a certain rotational speed, so the resultant of the velocity will produce a hydrodynamic force [4]. Darrieus turbine is generally used as a wind power plant, but in research and trials in several places Darrieus turbines are very potential to be developed as marine currents. This turbine has various advantages including ease of manufacture, installation and maintenance. This modular and reliable turbine design can withstand high- speed currents. The darrieus turbine used in ocean currents is type H which consists of 3 blade blades, this type is divided into two types, namely straight blade type and helix blade (gorlov). In theory, the amount of efficiency produced by wind turbines is 0.59 according to the Betz limit (Betz limit), taken from the German scientist (Albert Betz). This figure theoretically shows the maximum efficiency that can be achieved, from the curve in Figure 1, it can be seen that the efficiency of Darrieus turbine reaches 0.45%. Momentary theory in stream tube by Froude provides a simple understanding of the problem of idealized rotor modeling by assuming that: • The acceleration of the propeller is uniform on all fluids passed. • Flow is without friction. • Style is distributed evenly across all profiles from stream tube. • Inrush and outflow only have the same path