Dominicus Danardono Dwi Prija Tjahjana

Bio: Dominicus Danardono Dwi Prija Tjahjana is an academic researcher from Sebelas Maret University. The author has contributed to research in topics: Turbine & Wind speed. The author has an hindex of 7, co-authored 65 publications receiving 182 citations.

Performance investigation of the crossflow water turbine by using CFD

Abstract: Crossflow water turbines can be an alternative energy for the development of pico-hydro power plants. Multiple interactions that occur from the flow of fluid that collides with the blade is one of the advantages of the crossflow type so that this turbine has a high power coefficient. The power coefficient of a turbine is influenced by several factors, including the blade depth ratio and blade number. The objective of this research was to study the effect of blade depth ratio and blade number on the power coefficient of crossflow water turbines. This research was done in 2 dimensions method (2D) using ANSYS Fluent software. Variations of blade depth ratios used in this study were 10%, 20%, and 30%, while variations of the blade number were 16, 19, and 22. Each variation was tested at tip speed ratio (TSR) 0, 0.109, 0.218, 0.327, and 0.436 with a constant water velocity of 3 m/s. The results of this research indicated that the crossflow water turbine at TSR 0.436 with blade depth ratio of 10% and blade number of 16 generated the highest power coefficient, which was equal to 0.187.

Simulation and experimental studies on braking response of inertial load using magnetorheological brake

Abstract: The study is aimed to develop, model and simulate a magnetorheological brake (MRB) system. The drum-type MRB comprises of a rotating disk immersed in magnetorheological fluids (MRFs) and surrounded by an electromagnet coil. The magnetized coil causes a solidification of the MR fluid so that the shear stress between the moving part and static part increases resulting in the decrement speed of the moving part. The shear stress can be varied by applying different electric current to the winding coil. In this paper, the study began from the part design using 3D modeling software, following with the finite element simulations involving the magnetostatic analysis. The mathematical model is derived based on drum-type MR brake. The simulation and experimental study on the stopping time and braking torque were also performed and compared to each other. Several performances in terms of torque versus time and speed decrement versus time were investigated by applying various electric current.

Perancangan Turbin Angin Tipe Savonius Dua Tingkat Dengan Kapasitas 100 Watt Untuk Gedung Syariah Hotel Solo

Abstract: Urban area has higher energy consumption than the rural or village area. The energy need of a country is mainly determined by energy consumption in the urban and city areas. On the other hand the dependency to the energy from fossil fuel must be reduced. Therefore to fulfill the energy needs in urban area, a clean and renewable energy must be used. One of the eco friendly and renewable energy that can be produced in urban area is wind energy. In this paper a Savonius wind turbine that has 100 Watt capacity was designed to produce energy in urban area. The Savonius wind turbine was designed to be installed on the roof of the Syariah Hotel Solo. The maximum wind velocity on the roof top based on the wind speed data recorded in the Adisumarmo Airport Surakarta, was 6.71 m/s. The Savonius wind turbine design has power coefficient (Cp) of 0.18 and tip speed ratio (λ) of 1. The aspect ratio (α) and the overlap ratio (β) of the wind turbine are 2 and 0.2 respectively. The turbine has 2 semi circular blade and has height (H) of 1.85 m and rotor diameter (D) of 0.92 m. Keywords : U rban area , R enewable energy , W ind turbine , S avonius , 100 W

Design of eddy current brake for electric motorcycle braking system

Abstract: Braking systems in motor vehicles generally use a braking system that utilizes friction. The braking performance will decrease caused by using friction rapidly. To overcome this, as an alternative, an electromagnetic braking system can be used by utilizing eddy currents, such as eddy current brakes (ECB). Eddy currents are generated when the rotor pass the magnetic field of the electromagnet. The research aim is to design an ECB system. The performance of the disk design will be determined in this study. The study is about the tendency of the ECB properties. The finite element (FEM) method is used by modeling ECB performance. The experimental results were used to validate the result. The test showed the results of braking using aluminum disk showed the best performance in 12.03 Nm. From these results, the combination of the disks is needed by an appropriate disk design.

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The solutions to electric vehicle air conditioning systems: A review

Abstract: The air conditioning (AC) system provides cool, heating and ventilation in the cabin of the electric vehicles (EVs). It is necessary to control the interior thermal environments of the vehicle and ensure safety in visibility. Because AC systems are electrically powered, vehicle range is reduced drastically when the AC system is operating. EVs present a particular challenge to the development of more efficient AC systems for automotive applications. In this paper, the state of the art for various AC system solutions to EVs was critically reviewed. The investigations of alternative solutions are continuing along many parallel routes, e.g. vapor compression refrigeration-dedicated heater AC systems, reversible vapor compression heat pump AC systems, non-vapor compression AC systems and integrated thermal management system combined AC and battery pack. The characteristics and particular applications of each solution have been extensively discussed. Finally, a comparison listing the various pros and cons of the different available solutions was presented.

Study the influence of using guide vanes blades on the performance of cross-flow wind turbine

Abstract: A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio; therefore, it is a good candidate for a self-starting turbine. This study aims to investigate the best configuration between guide vanes and cross-flow vertical axis wind turbine. The experiment test was carried out to determine the turbine with the highest power coefficient. The cross-flow turbine has 14, 18, and 22 blades with using 6,10 and 14 blades of guide vane (GV) was developed in this study, employing 15°, 25°, 35°, 45°, 55°, 65°, and 75° of tilt angles in fifth different wind speed conditions 4 m/s, 6 m/s, 7.5 m/s, 9.20 m/s, and 11 m/s. The turbine has 22 blades with 14 GV blades at 55° of tilt angle blades producing more remarkable turbine performance improvement than other blades. The highest power coefficient (CP) of cross-flow using 14 GV blades at 55° was 0.0162 at 0.289 TSR, which increased around 59% of the turbine's performance using GV.