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Simulasi karakteristik mesin termoakustik pembangkit listrik dengan penambahan model kerugian minor dari dua segmen konis Nurpatria, N.; Mirmanto, M.; Padang, Y.A.; Nurchayati, N.
Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin Vol 14, No 2 (2024): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v14i2.845

Abstract

Acoustic energy output level from regenerator segment of a thermoacoustic engine model is attenuated along it’s loop due to several conditions including minor losses. This article discusses the result of Delta EC simulation of a thermoacoustic engine model acting as simple electric power generator that inserted with two conical segments. The cone segments are capable to lower the energy loss which in turn improve the overall performance of the engine in term of nett heat to acoustic energy conversion efficiency. Combined acoustic energy loss induced by both cones is equivalent to 4.94 watts minor losses. At this condition, regenerator segment amplifies the incoming acoustic energy flow of 57.02 watt up to 93.57 watt, which is equals to 36.55 watts acoustic amplification. It leads to increasing of overall engines heat to acoustic efficiency into 14.05%, which is 1.29% higher than those at the case of without cones. This engine performance improvement addressed to smoother streamline of working fluid flow inside the loop.
Simulasi pemasangan sebuah model kerugian minor perubahan penampang di konektor loop mesin termoakustik Nurpatria, N.; Mirmanto, M.; Joniarta, I.W.; Padang, Y.A.; Susana, I.G.B.
Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin Vol 13, No 1 (2023): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v13i1.626

Abstract

A custom-designed thermoacoustic engine model has been created with the open source Delta EC simulation software. The specific design of the engine lies in the part of the heat exchanger, which allows it to receive heat from the hot gas stream resulting from the combustion of low grade biomass directly. The engine model can be coupled with a loudspeaker model that functions as a liner alternator, resulting in a simple power generator engine model. In this study, further simulations were carried out to increase the total efficiency of converting heat energy into electricity from the previous model. After that a model of minor loss of cross-sectional change was also added to the model. In a certain set of engine model parameter values without minor losses, the efficiency of converting heat energy to acoustic energy is 12.76%, equivalent to the amplification of acoustic energy by a regenerator of 33.26 W. The total efficiency of the engine model in converting heat energy into electrical energy is 10.53%. After the addition of a sub-program of minor losses due to the effect of one conical segment, there was an acoustic energy loss of 0.11 W. So that the efficiency of converting heat energy to acoustic energy was reduced by 0.01% to 12.75%. As a result, relatively small change occur in the total efficiency of the engine model.
Wind turbine optimization through optimal blade shape design for low wind speeds Tira, H.S.; Juliawan, Y.; Padang, Y.A.; Nurpatria, N.
Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin Vol 13, No 1 (2023): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v13i1.631

Abstract

Current electricity needs continue to rely on depleting fossil fuels such as fossil fuel and coal. The current government effort is to find non-fossil fuel alternative energy sources. Wind energy is one of the efforts to use ecologically friendly renewable alternative energy. Studies on the development and use of new and renewable energy are now undertaken. One of them is a series of research on the utilization of wind in numerous places of Indonesia through the construction of wind turbines. The blade that explicitly makes contact with the wind is one of the most critical sections of a wind turbine. The shape of the airfoil determines whether or not the blade is used. The focus of this research was to determine the optimal type of airfoil by comparing the coefficient of power (Cp), maximum power, and lowest power produced by various NACA (National Advisory Committee for Aeronautics) airfoils. NACA 4410, 4412, and 4415 airfoils were employed in this study.
Analysis of cross-sectional area of digester on biogas production rate Tira, H.S.; Padang, Y.A.; Sukrenewita, I.K.
Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin Vol 11, No 1 (2021): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (218.606 KB) | DOI: 10.29303/dtm.v11i1.423

Abstract

Biogas has become one of the promising alternative fuels. This is triggered by relative ease of production while on the other hand the raw material is cheap and easy to be obtained. In order to get higher biogas production rate, a work has been done with digester cross-sectional area modification.  Under the modification an improvement in biogas yield was obtained. The research also has opened up new outlook to set up a better digester design for maximum biogas production. The experimental results showed that a higher biogas volume yield was obtained in larger cross-sectional area compared to that of smaller one. Increasing the cross-sectional area twice will benefit at least three times in terms of biogas volume produced under similar raw material input volume. A wide-open cross-section surface is a major factor for good breeding of microbial to produce methane. Under the condition, microbes experience less pressure due to the evenly distributed volume of the substrate which resulted in a comfortable environment for bacteria.
Effect of inlet air velocities on freshwater mass and heat transfer rates in an air-water harvester 0.5 PK Mirmanto, M.; Padang, Y.A.; Mari, A.K.
Dinamika Teknik Mesin Vol 15, No 2 (2025): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v15i2.1168

Abstract

During the dry season, some regions experience a shortage of clean water due to drought. Air water harvesters utilize the principle of condensation to produce clean freshwater from humid air can be alternative to solve the drought. This device works by condensing water vapour in the air using an evaporator. The focus of this study was on the effect of air velocities on the freshwater production and heat transfer rates. This research was conducted experimentally using refrigerant R134a as the working fluid. The compressor used was a 0.5 HP rotary compressor. The inlet air velocities applied were 0 m/s, 1.5 m/s, and 3 m/s. The results showed that the highest average mass of water obtained was 3.73 kg using the air velocity variation of 3 m/s. Meanwhile, the total heat flow absorbed by the evaporator from the air was highest also at the air velocity variation of 3 m/s, which was 1238.22 W. Increasing inlet air velocities raises the freshwater production and heat transfer rates.
Effect of inlet air velocity on air-water harvester machines using one and two evaporator with 1.5 PK compressor power Vayasqi, M.A.; Padang, Y.A.; Mirmanto, M.
Dinamika Teknik Mesin Vol 15, No 2 (2025): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v15i2.1077

Abstract

During the dry season, clean water crisis often occurs in various parts of Indonesia. As a result, clean potable water is difficult to obtain. Therefore, this research uses an air-water harvester machine, because this machine can be used anywhere as long as there is a source of electricity at that location. This study aims to determine the effect of inlet air velocity on air-water harvester machines using one and two evaporators with 1.5 PK rotary compressor power on water mass and total heat transfer rate. The method used in this research is the experimental method, with variations in inlet air velocity of 0 m/s, 1.5 m/s and 3 m/s, using one and two split AC fin type evaporators each with a capacity of 0.5 PK, with a pipe diameter of 7.65 mm. The refrigerant used is R32. The study was conducted from 09:00 to 16:00, for 18 days, 7 hours per day. The results showed that the higher the air velocity used and the increase in the number of evaporators, can increase the mass of water and the heat transfer rate obtained. The highest mass of water and heat transfer rate obtained in this study is in the air velocity variation of 3 m/s using two evaporators, which is 4.073 kg of water mass for 7 hours and a total heat transfer rate of 1375.09 W.
Simulasi karakteristik mesin termoakustik pembangkit listrik dengan penambahan model kerugian minor dari dua segmen konis Nurpatria, N.; Mirmanto, M.; Padang, Y.A.; Nurchayati, N.
Dinamika Teknik Mesin Vol 14, No 2 (2024): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v14i2.845

Abstract

Acoustic energy output level from regenerator segment of a thermoacoustic engine model is attenuated along it’s loop due to several conditions including minor losses. This article discusses the result of Delta EC simulation of a thermoacoustic engine model acting as simple electric power generator that inserted with two conical segments. The cone segments are capable to lower the energy loss which in turn improve the overall performance of the engine in term of nett heat to acoustic energy conversion efficiency. Combined acoustic energy loss induced by both cones is equivalent to 4.94 watts minor losses. At this condition, regenerator segment amplifies the incoming acoustic energy flow of 57.02 watt up to 93.57 watt, which is equals to 36.55 watts acoustic amplification. It leads to increasing of overall engines heat to acoustic efficiency into 14.05%, which is 1.29% higher than those at the case of without cones. This engine performance improvement addressed to smoother streamline of working fluid flow inside the loop.
Simulasi pemasangan sebuah model kerugian minor perubahan penampang di konektor loop mesin termoakustik Nurpatria, N.; Mirmanto, M.; Joniarta, I.W.; Padang, Y.A.; Susana, I.G.B.
Dinamika Teknik Mesin Vol 13, No 1 (2023): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v13i1.626

Abstract

A custom-designed thermoacoustic engine model has been created with the open source Delta EC simulation software. The specific design of the engine lies in the part of the heat exchanger, which allows it to receive heat from the hot gas stream resulting from the combustion of low grade biomass directly. The engine model can be coupled with a loudspeaker model that functions as a liner alternator, resulting in a simple power generator engine model. In this study, further simulations were carried out to increase the total efficiency of converting heat energy into electricity from the previous model. After that a model of minor loss of cross-sectional change was also added to the model. In a certain set of engine model parameter values without minor losses, the efficiency of converting heat energy to acoustic energy is 12.76%, equivalent to the amplification of acoustic energy by a regenerator of 33.26 W. The total efficiency of the engine model in converting heat energy into electrical energy is 10.53%. After the addition of a sub-program of minor losses due to the effect of one conical segment, there was an acoustic energy loss of 0.11 W. So that the efficiency of converting heat energy to acoustic energy was reduced by 0.01% to 12.75%. As a result, relatively small change occur in the total efficiency of the engine model.
Wind turbine optimization through optimal blade shape design for low wind speeds Tira, H.S.; Juliawan, Y.; Padang, Y.A.; Nurpatria, N.
Dinamika Teknik Mesin Vol 13, No 1 (2023): Dinamika Teknik Mesin: Jurnal Keilmuan dan Terapan Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/dtm.v13i1.631

Abstract

Current electricity needs continue to rely on depleting fossil fuels such as fossil fuel and coal. The current government effort is to find non-fossil fuel alternative energy sources. Wind energy is one of the efforts to use ecologically friendly renewable alternative energy. Studies on the development and use of new and renewable energy are now undertaken. One of them is a series of research on the utilization of wind in numerous places of Indonesia through the construction of wind turbines. The blade that explicitly makes contact with the wind is one of the most critical sections of a wind turbine. The shape of the airfoil determines whether or not the blade is used. The focus of this research was to determine the optimal type of airfoil by comparing the coefficient of power (Cp), maximum power, and lowest power produced by various NACA (National Advisory Committee for Aeronautics) airfoils. NACA 4410, 4412, and 4415 airfoils were employed in this study.