UTCC Scholarhttps://scholar.utcc.ac.thThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Sat, 10 Apr 2021 21:13:48 GMT2021-04-10T21:13:48Z5031Acceleration 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/6626976254/36162010-01-01T00:00:00ZFundamental 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/6626976254/3551