Shinji Takeshita

Carbon Dioxide Emission Free Power Generation System

Cpo = specific heat of oxygen at constant pressure Tin = inlet temperature of oxygen compressor Tout = outlet temperature of oxygen compressor Pin = inlet pressure of oxygen compressor Pout = outlet pressure of oxygen compressor ṁo = mass flow rate of oxygen Qeo2 = electric power of oxygen compressors h1 = inlet enthalpy of CO2 compressors h2 = outlet enthalpy of CO2 compressors Qeco2 = electric power of CO2 compressors Qin = combution energy of methane Cp = specific heat of combustion gas at constant pressure γo = adiabatic constant of oxygen ηa = adiavatic efficiency of compressors ηc = mechanical efficiency of compressors

The Effects of Swirl Vane for Disk MHD Accelerator

The purposes of current study are to compare the performances with-and-without inlet swirl of the Disk MHD Accelerator, and to find out its effects. With an inlet swirl, results of calculation show that it is able to improve the MHD compression. In case of the swirl ratio of -1.0, a maximum velocity of about 3100 m/s is obtained. These are because of the influence of the electric field that is caused by the strong Lorenz force Fr and the counter clockwise of the gas flow uθ. Nomenclature u = gas velocity, m/s E = electric field, V/m j = current density, A/m 2 σ = electrical conductivity, S/m β = Hall parameter ρ = gas density, kg/m 3 B = magnetic flux density, T T = temperature, K PL = pressure loss, Pa QL = thermal loss, W CP = specific heat at constant pressure, J/kg/K CV = specific heat at constant volume, J/kg/K ES = total enthalpy, J/m 3 R =

The Fundamental Properties of Disk-Shaped MHD Accelerator

Although the Disk-shaped MHD Accelerator has seldom been studying at anywhere, it has many predictable merits. The purpose of this paper is to verify and analyze the performances of the Disk-shaped MHD Accelerator and to confirm its advantages. From the present results, shorter MHD channel, in particular, the gas velocity of channel length of 4.5 cm showed the highest performance and the thermal loss also decreased to about 9.36 %. Despite MHD compression appeared, we have found that these performances could be improved by increasing the channel height. Nomenclature u = Gas velocity, m/s E = Electric field, V/m j = Current density, A/m 2 σ = Electrical conductivity, S/m β = Hall Parameter ρ = Fluid density, kg/m 3

Study on Specific Mass of Nuclear Electric Propulsion System with Closed Cycle MHD Generator

In space, radiation dose to crew increases in proportion to a increase of flight-time. High radiation dose to human have an influence on human health. Therefore, propulsion system that can minimize in-flight time is required. In the present study, to minimize in-flight time, nuclear electric propulsion system (NEP system) is suggested for human exploration to Mars. NEP system consists of CCMHD power generation system driven by nuclear fission reactor (NFR) providing electric power to the propulsion system and the variable specific impulse magneto-plasma rocket (VASIMR). In this study, modeling of power plant for NEP system and system analysis of it is carried out. Then Parameter are changed, the outlet temperature of NFR, the radiator temperature and the enthalpy extraction of MHD generator, in order to know how to minimize specific mass In the outlet temperature of NFR change, specific mass of NEP system decreases with an increase of outlet temperature of NFR. In the radiator temperature change, specific mass of NEP system have minimum point in radiator temperature. In the enthalpy extraction of MHD generator, specific mass of NEP system have minimum point in enthalpy extraction. Specific mass of NEP system less than ] / [ 2 kWe kg system   could be expected.

The Effect of Magnetic Nozzle for Disk Magnetohydrodynamics Accelerator

AbstractThe purpose of this article is to investigate the effect of magnetic nozzle for disk Magnetohydrodynamics (MHD) accelerator using by Q1D (quasi-1-dimentional) numerical simulation. As results, as constant applied magnetic field of 2T is supplied to the MHD channel and 3, 6, 8 and 10T are supplied to the nozzle, acceleration performance for these cases could not observe the significant difference. However as applied magnetic field of 3, 6, 8 and 10T are supplied to downstream side of the MHD channel and the nozzle, gas velocity for case of 6T was accelerated to 3170m/s and 10T was accelerated to 3040m/s. Because of excessive applied magnetic field induced compression due to joule heating and friction loss.

Performance evaluation of disk MHD accelerator with nozzle and diffuser

The channel shape of disk MHD accelerator is so unique for the propulsion system, and it has some advantages for the acceleration. This work is to evaluate the performance of disk MHD accelerator with nozzle and diffuser. Q1D program is used as an analysis program. As results, radial gas velocity is increased up to 3,100 (m/s) at the middle of diffuser. In addition the velocity is suddenly decreased, and gas pressure gained at the close to channel inlet at the same time. This phenomenon is called as MHD compression whose reason was the interaction of Lorenz force, in particularly much Hall current density is done. And the work of diffuser could show the recovering of the gas pressure about 0.01(MPa) from the back side to the exit of the diffuser. Therefore electrical conductivity in the diffuser was increased.

Comparative Study Inflow and Outflow of Disk MHD Accelerators

Although Disk MHD Accelerator has seldom been studying at anywhere, it has many predictable merits and it is able to flow to Inflow and Outflow direction. The purpose of this paper is to compare with the performances of Inflow and Outflow Disk MHD Accelerators and to confirm their advantages. From the present results, Inflow of 1MW case, thermal loss was slightly more than that of Outflow case. However it was shown that input current was able to reduce 15% in order to acquire same performances. And achieved the gas velocities at the exit was about 3200m/s for both cases of Inflow and Outflow. Nomenclature u = gas velocity, m/s E = electric field, V/m j = current density, A/m 2 σ = electrical conductivity, S/m β = Hall parameter ρ = gas density, kg/m 3