Aditya Rachman
Haluoleo University, Mechanical Engineering, Faculty Member
- Mechanical Engineering, Wind Engineering, Renewable Energy, Wind Energy, Sustainable Development, Wind turbine, and 20 moreBiomass energy, Civil Infrastructure Asset Management, Energy Economics, Solar Energy, Sustainable Energy, Biomass, Alternative Energy, Electricity, Solar Energy Technology, Home Power, Energy, Wind Power, Wind Farm, Automobile Manufacturing Industry, Applied aerodynamics, Turbulent boundary layer, Experimental Fluid Dynamics, Distributed generation & energy storage systems, Thermal Power Plants, and Renewable Biomass Energy From Rice Huskedit
- I'm a lecturer in the Department of Mechanical Engineering of Haluoleo University.edit
The role of university to raise the awareness on the importance of the clean renewable energy development for communities is so indispensible. The application of the solar energy technology in the university area to support the... more
The role of university to raise the awareness on the importance of the clean renewable energy development for communities is so indispensible. The application of the solar energy technology in the university area to support the electricity generation could be an appropriate starting point to deliver the awareness to students, the representation of the community in the campus. Halu Oleo University, one of the universities in Southeast Sulawesi, a developing province in eastern part of Indonesia with still current lack of the energy access, has potential to contribute in generating the student’s awareness by applying of the solar technology in the campus area. One of the important initial stages to apply this technology in the campus is to obtain the information on the solar energy potential and the appropriate strategies for the technology to obtain high sun power output. This information should be very useful in determining whether the technology will be technically and economically feasible. The aim of this study is to assess the potential solar energy, the technical strategy and the economic on the application of the photovoltaic (PV) energy technology in the campus area of Halu Oleo University Indonesia. The mathematical model of the solar radiation falling on a tilted surface, combined with the data of the solar global radiation obtained from the NASA Langley Research Center Atmospheric Science Data Center Surface meteorological and Solar Energy (SSE) web portal and the economical model of the Levelized Cost of Energy (LCOE) are utilized to perform the assessment. It proposes some technical strategies on various tilt angle and orientation on a solar PV panel. The result shows that the potential annual solar energy is around 2092 KWH/m2 annually. In the technical strategy aspect, positioning the panel parallel to the earth surface can derive the high annual energy generation (around 209 KWH/m2) and potentially obtain the lower energy cost than those of the government solar energy purchased price (Feed-in Tariff) and some other energy costs.
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The maximum efficiency of the conventional wind turbine is known as the Betz Limit (0.59). It seems that this efficiency limit does not simply come from design flaws. Aerodynamically, some references explain the flow expansion toward the... more
The maximum efficiency of the conventional wind turbine is known as the Betz Limit (0.59). It seems that this efficiency limit does not simply come from design flaws. Aerodynamically, some references explain the flow expansion toward the downstream by the factor of twice to the corresponding rotor area to be the cause for the phenomena. Even many of these references explain the caused factors for this limit, the comprehensive discussion regarding to the reason for the flow expansion seems still to be less explored. This paper attempts to discuses more comprehensively the factors causing the Betz Limits, in relation to the flow expansion. The mathematical model of the Disk Theory using the simulation program of MATLAB is utilized in assisting to figure the factors for the flow expansion causing the limit. The result indicates that phenomenon of the amount of the mass flow rate through the rotor constrained by the requirement to generate the thrust in the rotor is the factor causing the limit as well as the flow expansion.
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The clean renewable energy technology development should be on the top government program priority in present day, as the current energy availability and environmental challenges over the majority in the use of the unclean conventional... more
The clean renewable energy technology development should be on the top government program priority in present day, as the current energy availability and environmental challenges over the majority in the use of the unclean conventional power technologies. University has potential role to support the clean renewable energy development through research activities. This study deals with designing the clean renewable power technology based on a horizontal axis shrouded river current for experimental purpose in Halu Oleo University Indonesia. To fulfill this objective, some parts on the turbine unit are designed to be adjustable, thus, possibly making the process for the experiment. The method utilized in this study is the combination of literature review, mathematical model use, design and manufacture on the turbine. The result of this study is a unit of the horizontal axis shrouded river current turbine in which some of its parts, such as the shrouding device and the blade angle, are adjustable for the experimental purpose.
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Proceeding 2015 International Conference on Alternative Energy in Developing Countries and Emerging Economies (AEDCEE 2015), will be published in Procedia Energy-Elsevier/ISI/SCOPUS
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Reducing the role of the conventional cooling machines into the building to make the thermal comfort is so imperative as their massive energy consumption and their contribution to the global climate change. Shifting into less energy... more
Reducing the role of the conventional cooling machines into the building to make the thermal comfort is so imperative as their massive energy consumption and their contribution to the global climate change. Shifting into less energy consumed cooling methods using the locally available vegetative sources as passive cooling, can be one of the appropriate methods. The aim of this study is to investigate the influence of trees to the thermal comfort performance in a building in Southeast Sulawesi, a region, geographically, located in the equator line with its high daily solar radiation intensity. It conducts an experiment on a small scale building with various tree configurations. The result shows that the trees provide the effect of lowering temperature and maintaining the relative humidity of air, contributing into making the thermal comfort-ability in the building. A comprehensive discussion, using the Psychometric chart, regarding to the reason for the phenomenon is also presented in this paper.
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For Southeast Sulawesi, a developing province in the eastern region of Indonesia, inhabited by around two million people with the low electricity ratio and low electricity per-capita conditions, the utilization of rice husk as energy... more
For Southeast Sulawesi, a developing province in the eastern region of Indonesia, inhabited by around two million people with the low electricity ratio and low electricity per-capita conditions, the utilization of rice husk as energy source seems to be a potential alternative approach to bring clean renewable decentralized power. This is because of the paddy’s domination on the land utilization and on the annual production of food crops, and, its progression annual production pattern in more than last decade. The aim of this study is to assess the potential, the economical attractiveness, and the projection on the application of rice husk as the electricity source in Southeast Sulawesi. It employs the statistical data, regarding to the paddy production obtained from the department of agriculture to assess the rice husk energy potential. The economical assessment is performed by employing the model of the Levelised Cost of Energy (LCOE). The comparison of the cost of the husk energy to those of the conventional energies is also conducted in this study.
The unbalance on the supply and demand on the energy has an impact on the escalating energy price and potentially impedes the development. One of the power demands comes from the energy utilization in the building sector, in which the... more
The unbalance on the supply and demand on the energy has an impact on the escalating energy price and potentially impedes the development. One of the power demands comes from the energy utilization in the building sector, in which the cooling system is among them. The application of the air conditioning based on the refrigerator system is obviously consuming much energy in the building. Thus reducing the role of this power consumed cooling system is so imperative. To apply the circulating fan or to employ the natural ventilation are among the alternative approaches to make a building cooler, without much consuming energy. The aim of this study is to investigate the effect the circulating fan and the natural ventilation, on the temperature and the humidity in a building in Southeast Sulawesi, a region with its high daily solar radiation. It conducts an experiment on a building model incorporated with the ventilation and the circulating fan. The result shows that by incorporating these alternative cooling devices, the temperatures in the building can be lower than that of a closed building (no fan and no ventilation). The magnitude in the decreasing on the temperature for the building with circulating fan is higher than that of the ventilation. Another result on the investigation shows that the relative humidity in the building with the circulating fan or the ventilation is relatively higher than that of the closed building
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The power system using the clean decentralized renewable horizontal axis river current turbine can be an alternative option in delivering locally and sustainably the energies for the communities inaccessible to the electricity connection.... more
The power system using the clean decentralized renewable horizontal axis river current turbine can be an alternative option in delivering locally and sustainably the energies for the communities inaccessible to the electricity connection. One of the important aspects in the technology design is the selection of the blade number. This aspects can raise several consequences including the performance, the manufacturing cost and the construction constrain. The performance must be on the top of the priority in the technology design as the river velocity is typically low which effortlessly brings the technology uneconomically attractive. This study deals with the investigation of effect of the blade number on the performance of the horizontal axis river turbine for low speed condition. The investigation is conducted by a parametric study with the mathematical model of the Blade Element Momentum. The results indicate that turbines with high blade number deliver a better performance than those with the lower blade number. However, the consequences will be the low rotation for the high bladed turbines thus requiring a high gearing ratio for the mechanical transmission. This study also discusses the reason for the results of the investigation and presents a recommendation for designing of the river turbine for such low speed condition in relation to the decision of the blade number.
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Energy plays an essential role in the development of a region. Currently the major source for energy comes from fossil fuel. One of the major unavoidable catastrophic consequences on the utilization of this form of energy is the... more
Energy plays an essential role in the development of a region. Currently the major source for energy comes from fossil fuel. One of the major unavoidable catastrophic consequences on the utilization of this form of energy is the production of greenhouse gas carbon emission raising the concern about the global challenge of the climate change. The clean renewable power potentially offers a promising solution in delivering clean energy to contribute in the mitigation of the greenhouse gases emissions. The role of developing nations on this mitigation is very important as the major population worldwide lives there. In Indonesia, one of the developing nations, the access of the energy is still becoming a challenge in several of its provinces. Southeast Sulawesi, one of the developing provinces in Indonesia, is still posing the barriers of electricity access for its communities. It is believed that this province has abundant unexplored natural clean energy resources which can be potentially utilized to support the distribution of the energy for the communities as well as to deliver the clean energy in order to contribute in the deceleration on the pace of the greenhouse gas emission. This paper discusses the prospect on the development of the clean renewable power in Southwest Sulawesi. The methodology of generating this paper is literature study of some journal papers, magazines, newspapers and authentic government data. The topic covers the geography-topography and socio-economic condition, the electricity utilization and the problem and the prospect of renewable energy development in Southeast Sulawesi. It is concluded that the natural resources of this province can potentially be harnessed to deliver clean energy in order to cope with its current challenge on the energy distribution for the communities as well as to support the mitigation on the climate change.
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The power system based on the horizontal axis turbines has been extensively employed to harness the kinetic energy of the moving fluid to generate the clean renewable energy in several domains, such as wind, river, and sea. The... more
The power system based on the horizontal axis turbines has been extensively employed to harness the kinetic energy of the moving fluid to generate the clean renewable energy in several domains, such as wind, river, and sea. The characteristic of the rotational speed is one of the prominent aspects in designing the power based on the horizontal axis turbine. This is the characteristic that can determine the quantity of the electricity production in the generator on the power technology system. The number of blades is another important aspect in designing the technology. It is believed that the number of blades not only determines the aerodynamic performance, the construction, and the production cost but also the turbine rotational speed characteristics. This study investigates the effect of the blade number on the rotational speed characteristic of a horizontal axis river current turbine. The methodology of generating the investigation is a parametric study using the blade element momentum theory. The result shows that the turbines with low blade number have high rotational speed characteristics while the turbines with high blade number have low rotational speed characteristics. The very low attack angle which yields into a low lift coefficient is one of the factors responsible for the inability of the turbines with high blade number to operate at high rotation. A further discussion on the results on this investigation relating to the hydrodynamic behavior is explored in this study. It is recommended that when a turbine is decided to have a high blade number, the transmission ratio should be high to obtain a high rotation in the generator.
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The detrimental impact on the environment over the utilization of the conventional energy based fossil fuel is obvious. Thus, the effort on the reduction on the dependency on this unclean fuel is salient. The application of the clean... more
The detrimental impact on the environment over the utilization of the conventional energy based fossil fuel is obvious. Thus, the effort on the reduction on the dependency on this unclean fuel is salient. The application of the clean renewable wind power can be one of the appropriate measures in supporting the effort in reducing the dependency on the unclean fuel. Performance is one of the essential aspects in determining the economic attractiveness on the technology application. One of the factors responsible to the performance of the power technology is the wind velocity acting on the rotor blade. The addition of a shroud element is believed to have a great promise to increase the velocity at rotor, thus possibly improving the performance of the wind turbine. This study presents an experiment on horizontal and vertical wind turbines incorporated with rounded shroud devices. The experiment is conducted in a vehicle to simulate the effect of the flow of wind. The results on this experiment indicate that the addition of the shroud device with geometry of diffuser improves the performance of the horizontal axis wind turbine. For the nozzle shroud geometry, it seems to less significantly improve the performance of the horizontal axis wind turbine. For the vertical turbine, the incorporation of the shroud devices, both nozzle and diffuser, has almost no effect to increase the performance. This study also presents the discussion for the reasons behind the experimental results by relating to the condition of the turbine rotation and the wind velocity inside the shroud devices.
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The horizontal hydro-kinetic river current turbine power technology is one of the renewable decentralized power services potential in delivering energy for the communities in remote regions inaccessible by electricity connection. The... more
The horizontal hydro-kinetic river current turbine power technology is one of the renewable decentralized power services potential in delivering energy for the communities in remote regions inaccessible by electricity connection. The utilization of the kinetic mechanism makes the application of the turbine less environmentally detrimental and more extensively available than the conventional hydro-energy which uses the level differences. However, the only kinetic mechanism of the turbine possibly brings the application to be less economically attractive since the low typical river velocity. This highly possibly results in the low turbine performance. Thus to make the turbine application economically feasible, in the design turbine stage, a preliminary figure on an efficient design is paramount. In order to contribute in satisfying this requirement, this study investigates the effect of the variation of the pitch angle, one of the design turbine parameters, on the horizontal axis river turbine performance. The investigation is conducted by a parametric study with the mathematical model of the Blade Element Momentum theory. The results indicate that the increasing of the pitch angle initially enhances the performance. However, too much pitch angle enhancement results in low performance and reduces the rotation operation which in turn it requires a high gearing ratio of the transmission system. This study also attempts to discuss the philosophy behind the results of the investigation, relating the phenomena to the hydrodynamic behaviour.
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The river current turbine is one of the clean decentralized renewable energy technologies potential in delivering locally the energy for the communities inaccessible by the electricity connection. In order to assist in optimizing a river... more
The river current turbine is one of the clean decentralized renewable energy technologies potential in delivering locally the energy for the communities inaccessible by the electricity connection. In order to assist in optimizing a river turbine design and predicting its performance, a mathematical model can be one of the alternative methods. This study is a continuous work on developing a mathematical model for a river current turbine with a horizontal axis rotor arrangement. In present model, the effect of blade parameters is included, providing a widening understanding on the system behavior of the turbine. To develop the model, the Blade Element theory which is generally applied for the wind turbine is adopted. The result shows that, to run the model, instead of the water velocity, the turbine radius, the rotation and the specific mass of water, it requires additional input parameters of the number of blades, the cord length of the blade, the blade angle and the data of the lift and drag coefficients of the cross sectional area of the blade. This study also presents the numerical calculation procedure to calculate the turbine performance using the developed model and conducts a parametric study to verify the model whether it satisfies the Betz limits, the maximum efficiency for water/wind turbine, or not.
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The mechanism of the kinetic energy conversion has been utilized in many applications in renewable energy technologies. One of the applications is a horizontal axis wind turbine. In deciding the number of the blade to be put into the... more
The mechanism of the kinetic energy conversion has been utilized in many applications in renewable energy technologies. One of the applications is a horizontal axis wind turbine. In deciding the number of the blade to be put into the turbine design, instead of the design costs and the construction constraints, the effect of the number on the performance also is one of the aspects needed to be considered. Many studies attempt to investigate theoretically, computationally and experimentally the effect of blade number on the turbine performance. But, it seems that less comprehensive information is derived from these studies regarding to the factor contributing to the results of the investigation. This study investigates the effect the number of blades on the performance of the horizontal axis wind turbine in a variation of a rotation operation and a wind velocity, and attempts to explore comprehensively the reason behind the results of the investigation. The method utilized is a parametric study using the mathematical model of the Blade Element Momentum theory. The results show that in all variation of the velocity, turbines with high blade numbers reach its maximum performance at a low rotation, while the turbines with the lower blade numbers reach its maximum performance at a higher rotation. Other fact form this investigation is that for all blade number turbines, at a low wind velocity, turbines reach its maximum performance at a low rotation, while at a high velocity turbines reach its peak performance at a higher rotation. It is found that a torque, a velocity at rotor and a wind relative angle generated contribute in shaping the phenomena in the results of the investigations.
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For the Celebes Island, the world's eleventh-largest island laying in the eastern part of Indonesia, consisting of six developing provinces, inhabited by around 19 million populations, the energy availability seems still to be a... more
For the Celebes Island, the world's eleventh-largest island laying in the eastern part of Indonesia, consisting of six developing provinces, inhabited by around 19 million populations, the energy availability seems still to be a challenge. Depending merely on the conventional fossil sources, to cope with this challenge, should be less appropriate as their limitation and detrimental environmental impacts. The role of these unclean conventional limit power sources can be potentially shifted into an alternative clean sustainable energy generation based on locally available rice husk. The aim of this study is to assess the potential, the environmental aspect and the economical attractiveness on the application of rice husk as the electricity generation in the Celebes Island. It proposes a model of a direct boiler combustion power plant model based on the rice husk biomass, combined with the statistical data on the annual paddy production obtained from the Department of Agriculture to assess the energy potential. The environmental assessment is conducted by calculating the lifecycle carbon-dioxide equivalent and the economical assessment is performed by employing the model of the Levelised Cost of Energy (LCOE). The result shows that the potential of the rice husk energy in this island is around 815 GWH annually under the proposed power plants, around ten percent of the current electricity use. The potential of the carbon dioxide emission generated by the proposed biomass power plants is less than five-percent of the total carbon dioxide emitted by current power plants installed. At a low feedstock cost, a low installation costs and a low discount rate, it is possible to obtain the LCOE of the biomass lower than the electricity production costs of some existing power sources, the electricity price under subsidy and the biomass purchased price under a government regulatory (Feed-in-Tariff (FIT)).