UTCC Scholarhttps://scholar.utcc.ac.thThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Wed, 14 Apr 2021 11:24:45 GMT2021-04-14T11:24:45Z5081Acceleration effect of swirl flow for disk MHD acceleratorhttps://scholar.utcc.ac.th/handle/6626976254/3602Title: Acceleration effect of swirl flow for disk MHD accelerator
Authors: Takeshita, S.; Buttapeng, C.
Abstract: The purpose of this study is to verify how the swirl vane influences the acceleration performance, namely, the radial gas velocity and the static gas pressure, for the Disk MHD accelerator. A quasi1dimensional (Q1D) numerical program is used for the calculations. Results of the current calculations show that the static gas pressure decreases approximately 40% when using the inlet swirl vane. It is found that the MHD compression phenomena, which generates at the closest to the MHD channel inlet due to the Joule heating, could suppress effectively. The maximum radial gas velocity of 3,380 m/s is successfully achieved at the channel exit when swirl ratio was 1.0,and swirl ratio was set to be 0.0 and mass flow rate was kept the same as that for the case of swirl ratio of 1.0 and 1.0. The acceleration efficiency of 40.5% and 36.7% are calculated when the swirl ratio is 1.0, and the case of swirl ratio was set to be 0.0 and mass flow rate was kept the same as that for the case of swirl ratio of 1.0 and 1.0 respectively. The difference of efficiency is due to increase the Hall parameter in the upstream and midstream of MHD channel. This current study can show and confirm the function of inlet swirl for Disk MHD accelerator.
Fri, 01 Jan 2010 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/36022010-01-01T00:00:00ZCharacteristics of plasma produced by MHD technology and its application to propulsion systemshttps://scholar.utcc.ac.th/handle/6626976254/3616Title: Characteristics of plasma produced by MHD technology and its application to propulsion systems
Authors: Takeshita, S.; Buttapeng, C.; Harada, N.
Abstract: This paper analyzes plasma characteristics for the newly proposed concept of a closedloop MHD power generation combined cycle system, which is used as a pulsedrivenMHD accelerator to accelerate plasma to high velocity, with a nuclear plant. In this paper, since the final goal is for the space propulsion system applications, the performance of a MHD acceleration system is also analyzed by the Q1D analysis program. Results reveal that the radial velocity with the MHD effect is accelerated rapidly at the channel exit, with a calculated maximum velocity of about 4700 m/s. Consequently, specific impulse approximately 480 s and thrust of about 6550 N are estimated. The static gas temperature is evaluated at less than 600 K, while the value of about 1800 K is calculated for the stagnation gas temperature in the MHD channel.
Fri, 01 Jan 2010 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/36162010-01-01T00:00:00ZNumerical study of an AC MHD generation with doublesideexciting windinghttps://scholar.utcc.ac.th/handle/6626976254/3571Title: Numerical study of an AC MHD generation with doublesideexciting winding
Authors: Intani, P.; Buttapeng, C.; Sasaki, T.; Kikuchi, T.; Harada, N.
Abstract: This paper studies physical phenomena, performance and optimal operating point of an AC MHD generator under the slip value by using a numerical simulation. The doubleside exciting winding of the generator is considered. Its structure consists of a channel, an insulator and stators. Channel type is a flat rectangular and the liquid flows along the channel as a conductor.Channel wall acted as an insulator separates metal fluid and stator coils. The top and bottom stator winding of the generator is connected to polyphase system. Under this condition, it can produce a magnetic field by means of time harmonic function in the same direction of the metal fluid. An interaction between traveling wave and metal fluid is explained by finite element method under Maxwell's equation and Ohm law. The distribution of magnetic vector potential and magnetic flux density throughout channel is evidently shown in xyplane.Power flow in AC MHD generator is evaluated by slip value. The optimal operating point of an AC MHD generator performance is reported by active power 0.99 kW, reactive power 50 kVAR, mechanical power 1.58 kW, power dissipation 0.59 kW and electrical efficiency 62.5%.
Sat, 01 Jan 2011 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/35712011-01-01T00:00:00ZAblation plasma characteristics of flyer acceleration using a multipulsed ion beam irradiationhttps://scholar.utcc.ac.th/handle/6626976254/3617Title: Ablation plasma characteristics of flyer acceleration using a multipulsed ion beam irradiation
Authors: Buttapeng, C.; Azuma, S.; Harada, N.
Abstract: This paper presents the investigation of ablation plasma characteristics together with the flyer velocity for flyer acceleration when irradiating the 50μmAl target with a multipulsed ion beam. A onedimensionalhydrodynamic model is used in the calculations.The CIP method is used to describe the ablation plasma production and the acceleration mechanism by the repetition of ion beam irradiation. In the calculations, two shots of ion beam, which has a total energy density of 120 J/cm2, are used. The time intervals between the first pulse and the second pulse of 0 ns, 20 ns, 50 ns and 100 ns were used for the investigation of flyer(target) velocity. Results indicate that irradiating the second pulse for 20 ns, 50 ns and 100 ns after the first pulse increases the flyer velocity by approximately 16%, 32% and 40%, respectively.
Fri, 01 Jan 2010 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/36172010-01-01T00:00:00ZNumerical analysis of ablation plasma produced by pulsed ion beam for various solid targetshttps://scholar.utcc.ac.th/handle/6626976254/3619Title: Numerical analysis of ablation plasma produced by pulsed ion beam for various solid targets
Authors: Buttapeng, C.
Abstract: This article presents the investigation of ablation plasma characteristics for flyer acceleration when different kinds of solid target materials (Au, Ag, Cu, and Pb) are irradiated with a pulsed ion beam. A onedimensional hydrodynamic model is used in thecalculations. The Lagrangean Scheme is used to describe the ablation plasma production and the acceleration mechanism. Of the four samples, numerical results reveal that Pb is the fastest material to be evaporated and expanded. Although Pb shows the greatest amount of ablation plasma production, it produces the ablation plasma with slowest velocity. In addition, the resultsshow that the heat capacity is one of the significant factors in predicting how fast the solid targets can be evaporated to form ablation plasma.
Fri, 01 Jan 2010 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/36192010-01-01T00:00:00ZSurface cleaning of metal wire by atmospheric pressure plasmahttps://scholar.utcc.ac.th/handle/6626976254/3633Title: Surface cleaning of metal wire by atmospheric pressure plasma
Authors: Nakamura, T.; Buttapeng, C.; Furuya, S.; Harada, N.
Abstract: In this study, the possible application of atmospheric pressure dielectric barrier discharge plasma for the annealing of metallic wire is examined and presented. The main purpose of the current study is to examine the surface cleaning effect for a cylindrical object by atmospheric pressure plasma. The experimental setup consists of a gas tank, plasma reactor, and power supply with control panel. The gas assists in the generation of plasma. Copper wire was used as an experimental cylindrical object. This copper wire was irradiated with the plasma, and the cleaning effect was confirmed. The result showed that it is possible to remove the tarnish which exists on the copper wire surface. The experiment reveals that atmospheric pressure plasma is usablefor the surface cleaning of metal wire. However, it is necessary to examine the method for preventing oxidization of the copper wire.
Thu, 01 Jan 2009 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/36332009-01-01T00:00:00ZFundamental performance of diskshaped magnetohydrodynamics acceleratorhttps://scholar.utcc.ac.th/handle/6626976254/3551Title: Fundamental performance of diskshaped magnetohydrodynamics accelerator
Authors: Takeshita, S.; Buttapeng, C.; Furuya, S.; Harada, N.
Abstract: This paper investigates the acceleration performance of a diskshaped magnetohydrodynamics (MHD) accelerator. Quasi1dimensional (Q1D) numerical simulation employing the MacCormack scheme was developed. For the longer channel length of 0.9 m, thermal loss was estimated at over 60% and effective acceleration could not be achieved owing to large heat loss and large friction loss. For shorter channel lengths, thermal loss can be reduced below 20% owing to the smaller heat and the frictionlosses. However, with too short a channel length, accelerator performance was decreased by the MHD compression due to excessive Faraday current density. The effect of ratio of cross sectional area on performance was also studied. For a larger area ratio, the gas can be accelerated smoothly throughout the MHD channel. However, for the excessive expansion case of a sevenfold channel, gas velocity near the exit decreased due to transition to a "generator mode". For the best accelerationperformance, the design channel length should be as short as possible preventing compression at the channel inlet. The area ratio should be large enough to prevent the compression but not too large, to prevent transition to a "generator mode".
https://scholar.utcc.ac.th/handle/6626976254/3551Fundamental of an AC MHD generation with singlesideexciting windinghttps://scholar.utcc.ac.th/handle/6626976254/3552Title: Fundamental of an AC MHD generation with singlesideexciting winding
Authors: Intani, P.; Buttapeng, C.; Sasaki, T.; Kikuchi, T.; Harada, N.
Abstract: This paper presents the possibility to generate the alternating current (AC) electrical power by using a linear MHD generator.The singlesided exciting winding of the generator is considered. Its structure consists of a channel, an insulator and stators. The channel type is a flat rectangular and the liquid flows along the channel as a conductor. The channel wall acted as an insulatorseparates the metal fluid and stator coil. The top stator winding of the generator is connected to polyphase systems. Under this condition, it can produce a magnetic field by means of time harmonics function in the same direction of the metal fluid. Energy in the channel is extracted by inductive coils at the bottom stator. An interaction between traveling wave and metal fluid isexplained by finite element technique. The distributions of magnetic vector potential and magnetic field throughout channel are evidently shown in xyplane.Power flow in an AC MHD generator is reported with magnetic Reynolds number and slip value.The optimized value of active power is suggested by small slip value as s < 0 and small magnetic Reynolds number.
Sat, 01 Jan 2011 00:00:00 GMThttps://scholar.utcc.ac.th/handle/6626976254/35522011-01-01T00:00:00Z