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Journal : Journal of Engineering and Technological Sciences

An Experimental Investigation of Passive Variable-Pitch Vertical-Axis Ocean Current Turbine Hantoro, Ridho; Utama, I.K.A.P; Erwandi, Erwandi; Sulisetyono, Aries
Journal of Engineering and Technological Sciences Vol 43, No 1 (2011)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (593.016 KB) | DOI: 10.5614/itbj.eng.sci.2011.43.1.3

Abstract

Vertical-axis hydrokinetic turbines with fixed pitch blades typically suffer from poor starting torque, low efficiency and shaking due to large fluctuations in both radial and tangential force with azimuth angle. Maximizing the turbine power output can be achieved only if the mechanism of generation of the hydrodynamic force on the blades is clearly identified and tools to design high-performance rotors are developed.This paper describes an initial experimental investigation to understand more of the performance on vertical-axis turbine related to the effect of fixed-pitch and passive variable-pitch application using airfoil NACA 0018. Comparative analysis according to aspects of rotation and tip speed ratios was discussed. Information regarding the changes of foil position in passive variable-pitch during rotation at a limited range of flow velocity variations test was obtained and analyzed. 
Thermal Energy Storage Optimization in Shopping Center Buildings Biyanto, Totok R.; Alhikami, Akhmad F.; Nugroho, Gunawan; Hantoro, Ridho; Bayuaji, Ridho; Firmanto, Hudiyo; Waluyo, Joko; Sonhaji, Agus Imam
Journal of Engineering and Technological Sciences Vol 47, No 5 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (419.021 KB) | DOI: 10.5614/j.eng.technol.sci.2015.47.5.7

Abstract

In this research, cooling system optimization using thermal energy storage (TES) in shopping center buildings was investigated. Cooling systems in commercial buildings account for up to 50% of their total energy consumption. This incurs high electricity costs related to the tariffs determined by the Indonesian government with the price during peak hours up to twice higher than during off-peak hours. Considering the problem, shifting the use of electrical load away from peak hours is desirable. This may be achieved by using a cooling system with TES. In a TES system, a chiller produces cold water to provide the required cooling load and saves it to a storage tank. Heat loss in the storage tank has to be considered because greater heat loss requires additional chiller capacity and investment costs. Optimization of the cooling system was done by minimizing the combination of chiller capacity, cooling load and heat loss using simplex linear programming. The results showed that up to 20% electricity cost savings can be achieved for a standalone shopping center building.
Novel Design of a Vertical Axis Hydrokinetic Turbine –Straight-Blade Cascaded (VAHT–SBC): Experimental and Numerical Simulation Hantoro, Ridho; Septyaningrum, Erna
Journal of Engineering and Technological Sciences Vol 50, No 1 (2018)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (455.594 KB) | DOI: 10.5614/j.eng.technol.sci.2018.50.1.5

Abstract

A promising technology to reduce dependency on fossil fuels is hydrokinetic energy conversion using either turbine and non-turbine technology. Hydrokinetic turbine technology is penalized by low efficiency and lack of self-starting. This study involved experimental testing and numerical simulation of a novel hydrokinetic turbine design, called a Vertical Axis Hydrokinetic Turbine – Straight-Blade Cascaded (VAHT–SBC). Three configurations of the design were tested. Model 1 had 3 passive-pitch blades, while Model 2 and Model 3 had 6 and 9 blades respectively, where the outer blades were passive-pitch and the others fixed-blade. Both in the experimental test and in the numerical simulation Model 3 outperformed the other two models. The Cp of Model 3 was 0.42, which is very close to the theoretical Cp for VAHTs (0.45). It worked properly at low TSR. A CFD simulation based on the RANS solver was performed to gain supplementary information for performance investigation. This simulation confirmed that the torque changes because of the change in angle of attack as the turbine rotates. Because they have different numbers of blades, each model has different periodical torque fluctuation patterns. This study verified that utilization of cascaded blades and a passive-pitch mechanism is able to improve turbine performance.
An Experimental Investigation of Passive Variable-Pitch Vertical-Axis Ocean Current Turbine Ridho Hantoro; I.K.A.P Utama; Erwandi Erwandi; Aries Sulisetyono
Journal of Engineering and Technological Sciences Vol. 43 No. 1 (2011)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2011.43.1.3

Abstract

Vertical-axis hydrokinetic turbines with fixed pitch blades typically suffer from poor starting torque, low efficiency and shaking due to large fluctuations in both radial and tangential force with azimuth angle. Maximizing the turbine power output can be achieved only if the mechanism of generation of the hydrodynamic force on the blades is clearly identified and tools to design high-performance rotors are developed.This paper describes an initial experimental investigation to understand more of the performance on vertical-axis turbine related to the effect of fixed-pitch and passive variable-pitch application using airfoil NACA 0018. Comparative analysis according to aspects of rotation and tip speed ratios was discussed. Information regarding the changes of foil position in passive variable-pitch during rotation at a limited range of flow velocity variations test was obtained and analyzed. 
Thermal Energy Storage Optimization in Shopping Center Buildings Totok R. Biyanto; Akhmad F. Alhikami; Gunawan Nugroho; Ridho Hantoro; Ridho Bayuaji; Hudiyo Firmanto; Joko Waluyo; Agus Imam Sonhaji
Journal of Engineering and Technological Sciences Vol. 47 No. 5 (2015)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2015.47.5.7

Abstract

In this research, cooling system optimization using thermal energy storage (TES) in shopping center buildings was investigated. Cooling systems in commercial buildings account for up to 50% of their total energy consumption. This incurs high electricity costs related to the tariffs determined by the Indonesian government with the price during peak hours up to twice higher than during off-peak hours. Considering the problem, shifting the use of electrical load away from peak hours is desirable. This may be achieved by using a cooling system with TES. In a TES system, a chiller produces cold water to provide the required cooling load and saves it to a storage tank. Heat loss in the storage tank has to be considered because greater heat loss requires additional chiller capacity and investment costs. Optimization of the cooling system was done by minimizing the combination of chiller capacity, cooling load and heat loss using simplex linear programming. The results showed that up to 20% electricity cost savings can be achieved for a standalone shopping center building.
Novel Design of a Vertical Axis Hydrokinetic Turbine –Straight-Blade Cascaded (VAHT–SBC): Experimental and Numerical Simulation Ridho Hantoro; Erna Septyaningrum
Journal of Engineering and Technological Sciences Vol. 50 No. 1 (2018)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2018.50.1.5

Abstract

A promising technology to reduce dependency on fossil fuels is hydrokinetic energy conversion using either turbine and non-turbine technology. Hydrokinetic turbine technology is penalized by low efficiency and lack of self-starting. This study involved experimental testing and numerical simulation of a novel hydrokinetic turbine design, called a Vertical Axis Hydrokinetic Turbine – Straight-Blade Cascaded (VAHT–SBC). Three configurations of the design were tested. Model 1 had 3 passive-pitch blades, while Model 2 and Model 3 had 6 and 9 blades respectively, where the outer blades were passive-pitch and the others fixed-blade. Both in the experimental test and in the numerical simulation Model 3 outperformed the other two models. The Cp of Model 3 was 0.42, which is very close to the theoretical Cp for VAHTs (0.45). It worked properly at low TSR. A CFD simulation based on the RANS solver was performed to gain supplementary information for performance investigation. This simulation confirmed that the torque changes because of the change in angle of attack as the turbine rotates. Because they have different numbers of blades, each model has different periodical torque fluctuation patterns. This study verified that utilization of cascaded blades and a passive-pitch mechanism is able to improve turbine performance.
Site Test Performance and Numerical Study of Vertical Axis Hydrokinetic Turbine Straight Blade Cascaded (VAHT–SBC) Ridho Hantoro; Sarwono Sarwono; Fernando Parsaulian Panjaitan; Erna Septyaningrum; Nuril Hidayati
Journal of Engineering and Technological Sciences Vol. 53 No. 1 (2021)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2021.53.1.2

Abstract

The Vertical Axis Hydrokinetic Turbine – Straight Blade Cascaded (VAHT-SBC) is a type of energy generation technology developed to meet the increasing demand for renewable energy. Previous studies have been carried out to enhance the efficiency of the turbine through several aspects. To deploy a turbine on site, a study on its power generation and conversion is needed. In this research, the VAHT–SBC was integrated with a permanent magnet synchronous generator (PMSG) by a pulley and belt transmission system. This study was conducted by experimental and numerical analysis. The CFD simulation result showed that the highest torque of the turbine was found at 0° and 360°, with an average value of 23.923 Nm and with current velocity at 0.92 m/s. The experimental data showed that the voltage and frequency were proportional to the generator rotational speed and inversely correlated with the load given to the integration system. In the inverter, the voltage and frequency values were stable at 230 V and 56 Hz respectively. The VAHT-SBC prototype was able to produce a maximum power of 50 W on site, with a current velocity of 0.82 and 0.92 m/s.