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18 results on '"Iswahyudi, Sigit"'

6. STUDI PEMBANGKITAN TORSI PADA CAKRAM BAJA MENGGUNAKAN GAYA-MEDAN MAGNET NEODYMIUM

Author

Iswahyudi, Sigit and Arnandi, Wandi

Subjects
Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

This works is a preliminary study that evaluates probability of torque generation in steel disc by field force of neodymium magnet. The study was started by analyzing ferromagnetic disc that is surrounded by magnets. In simulation, the disc had a diameter of 400 m and was made of S416. The magnets used in the simulation had cubed form and length of 10 mm. The magnets were placed around the disc in such a way that the center of their poles made an angle of 42 degrees from the disc radii. The nearest distance between center magnet poles to the center of the disc was 210.6 mm. There were six configurations of magnets to be evaluated, i.e. configurations of 1, 2, 4, 8, 16 and 32 magnets. Effects of magnet configurations on torque generation in the disc were evaluated by using MagNet software. Simulation results show that the highest torque was achieved by 16 magnet configuration.

Published
2017

7. STUDI EKSPERIMENTAL PEMBANGKITAN GAYA MAGNETIK PADA KUMPARAN BERARUS DALAM MEDAN MAGNET NEODYMIUM

Author

Arnandi, Wandi and Iswahyudi, Sigit

Abstract

This research is a preliminary study to develop a magnetic force generator as a thrush force of vehicle. The purpose is to investigate the effect of electric current and coil diameter on the generation of magnetic force of current-carrying coilconductor in magnetic field of neodymium magnet. To reach the goal, a magnetic circuit and three coil which havea difference of coil diameter were made and tested. The coilswere made of laminated copper wirewhich have 1,1 mm in diameter and 3000 mm length. The coil diameter was varied 35 mm, 38 mm, and 50 mm. The source of magnetomotive force in the magnetic circuit was cylindrical neodymium magnet.The source of dc current was power supply which can produce 30 ampere of output dc current and output voltage that can be varied. The electric current in the coil was set up 1,0 ampere; 2,0 ampere; 3,0 ampere; 4,0 ampere; 5,0 ampere; 6,0 ampere; and 7,0 ampere. Testing was carried out by flowing current in the coil which placed in the magnetic flux of magnetic circuit and then magnetic force produced by the coil was measured using spring scale in unit of Newton. Result shows that the magnitude of magnetic force produced by thecoil is directly proportional tothe magnitude of electric current and coil diameter.

Published
2017

10. Dimensional Analysis of Horizontal Axis Wind Turbine Scaling Design.

Author

Iswahyudi, Sigit, Sutrisno, and Prajitno

Subjects
*HORIZONTAL axis wind turbines, *WIND turbine design & construction, *DIMENSIONAL analysis, *PERFORMANCE of wind turbines, *WIND turbines, *WIND tunnels
Abstract

Observation of a small-scale wind turbine in a wind tunnel is a preliminary way to produce data that would describe the aerodynamic characteristics of the large one. The full-scale wind turbine has much greater Reynolds number than the miniature that makes the data might not be valuable directly. In this paper, the application of the Buckingham π theorem is studied in predicting the performances of the full-scale wind turbine based on the small-scale wind turbine performances. The blade element momentum theory (BEMT) computation procedure is used to generate torque and thrust data of wind turbines that have diameters of 2.4 m, 10.0 m, 50.0 m, and 75.0 m. The generated data from the smallest rotor is prepared as small-scale wind turbine data. Based on the small-scale rotor data, the analysis produces equations expressing the correlation of rotor torque and thrust associated with diameters. Then, the powers of the wind turbines computed by BEMT are compared with the powers estimated by the dimensional analysis. The results show that the technique gives excellent accuracy. Therefore, it can be used confidently to assess the power measurement results of the large-scale rotor. [ABSTRACT FROM AUTHOR]

Published
2019
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13. Field Performance Measurement of Small-Scale Three-Dimensional (3-D) Wind Turbines.

Author

Sutrisno, Iswahyudi, Sigit, Wibowo, Setyawan Bekti, Kartika, Widia, and Qomar, Fadhil

Subjects
*WIND turbines, *WIND turbine blades, *ROTORS, *ANEMOMETER, *POLYNOMIALS
Abstract

This paper presents field performance measurement of a small scale 3-D wind turbine rotor blade design and a standard straight rotor blade design. The measurements were conducted at a point located 10 m from the shoreline in Yogyakarta, Indonesia. The rotors were mounted on a tower as high as 7 m. The rotors and an anemometer were installed at the same height and the distance between the anemometer and the tower is 4.5 m. Bin method with bin speed of 0.5 m/s is applied to analyze the recorded data.4th order polynomial trend line is used to characterize the calculated mean powers. The results show that 3-D wind turbine blade design yields higher power output and better performance than the standard blade design. [ABSTRACT FROM AUTHOR]

Published
2018
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14. The Structured and Unstructured CFD Characteristic Studies of 3-D Backward Wind Turbine Blades.

Author

Sutrisno, Deendarlianto, Rohmat, Tri Agung, Indarto, Setyawan B. W., Iswahyudi, Sigit, Dhanu, A., and Djatmiko

Subjects
COMPUTATIONAL fluid dynamics, WIND turbine blades, CENTRIFUGAL force, ACCELERATION (Mechanics), AERODYNAMICS
Abstract

The paper would report the aerodynamic CFD model characteristic studies of backward 3-D wind turbine blades in operation. It is found that the blade lip of the bottom section is suffered from strongly decelerated disturbance, while the upper section are accelerated. The region influenced by radial disturbance starts radially from the top toward the bottom part of the blade, from lightly disturbed to weakly disturbed region. Original radial source of disturbance, caused by centrifugal and Corriolis force, are still persist. Q-criterion was used to benchmark for the quality of computation to justify the most sensitive outcome, to determine the largest size for the smallest computational cell. Compare to structured grids, the unstructured grids gives significant results errors. [ABSTRACT FROM AUTHOR]

Published
2018
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17. Vortex Dynamics Study of the Canard Deflection Angles' Influence on the Sukhoi Su-30-Like Model to Improve Stall Delays at High AoA.

Author

Sutrisno, Rohmat, Tri Agung, Wibowo, Setyawan Bekti, and Iswahyudi, Sigit

Subjects
ANGLE of attack (Aerodynamics), LIFTING bodies (Aeronautics), COMPUTATIONAL fluid dynamics, WATER tunnels, VORTEX motion
Abstract

The maneuverability of the Sukhoi Su-30 at very high angles of attack (AoA) was remarkably appealing. Canard angle, in cooperation with aircraft wing, created a flow pattern whereby, in that position, the fighter still had as much lifting force as possible in order not to stall. The behavior of changing canard angle configuration played an essential role in creating the strong vortex core so that it could delay the stall. The study of vortex dynamics at canard deflection angle gave an essential function in revealing the stall delay phenomenon. In this study, one could analyze the flow patterns and vortex dynamics ability of the Sukhoi Su-30-like model to delay stall due to the influence of canard deflection. The used of water tunnel facilities and computational fluid dynamics (CFD) based on Q-criterion has obtained clear and detailed visualization and aerodynamics data in revealing the phenomenon of vortex dynamics. It was found that between 30° and 40° canard deflection configurations, Sukhoi Su-30-like was able to produce the most robust flow interaction from the canard to the main wing. It was clearly seen that the vortex merging formation above the fighter heads was clearly visible capable of delaying stall until AoA 80°. [ABSTRACT FROM AUTHOR]

Published
2019
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18. Dimensional Analysis of Power Prediction of a Real-Scale Wind Turbine Based on Wind-Tunnel Torque Measurement of Small-Scaled Models.

Author

Sutrisno, Iswahyudi, Sigit, and Wibowo, Setyawan Bekti

Subjects
*WIND turbines, *WIND tunnels, *AERODYNAMICS, *TORQUE, *WIND power
Abstract

A preliminary study of a horizontal-axis wind turbine (HAWT) design is carried out using a wind tunnel to obtain its aerodynamic characteristics. Utilization of data from the study to develop large-scale wind turbines requires further study. This paper aims to discuss the use of wind turbine data obtained the wind-tunnel measurements to estimate the characteristics of wind turbines that have field size. One should measure the torque of two small-scale turbines inside the wind tunnel. The first small-scale turbine has a radius of 0.14 m, and the radius of the second small turbine is 0.19 m. Torque measurement results from both turbines were analyzed using the Buckingham π theorem to obtain a correlation between torsion and diameter variations. The obtained correlation equation was used to estimate the field measurement of turbine power with a radius of 1.2 m. The resulting correlation equation can be applied to approximate the energy generated by the turbine using the size of the field well in the operating area and the tip-speed ratio (λ) of the turbine design. [ABSTRACT FROM AUTHOR]

Published
2018
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