研究者詳細 - 杵淵　紀世志

Experimental and numerical simulation study of liquid-propellant draining from rocket tanks 査読有り

Kinefuchi K., Kamita T., Negishi H., Yamada K., Fujimura M.

Journal of Spacecraft and Rockets 47 巻 ( 5 ) 頁： 860 - 863 2010年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Spacecraft and Rockets

The draining process for the circular-plate-type device, using both experiments and numerical simulations was investigated. The effect of turbulence was evaluated by conducting both turbulent and laminar flow calculations. The Navier-Stokes equation was spatially discretized by the finite-volume method, and the convective flux was evaluated by a second-order upwind scheme. The air and water gas-liquid two-phase flow was modeled by the volume-of-fluid (VOF) method, and the surface tension of water was assumed to have a 75° contact angle to the wall. The cell distribution of the normal 2-D grid and radial cross section of the 3-D grid were similar and the minimum grid size was 0.125 mm around the baffle edge and the maximum was approximately 5 mm at the tank equator for both grids. A numerical accuracy study based on Richardson statistics indicated that the fractional errors of the liquid remaining were roughly 19 and 1.2% for the normal and finer-grid systems, respectively.

DOI： 10.2514/1.48398

Experimental investigation on microwave interference in full-scale solid rocket exhaust 査読有り

Kinefuchi K., Funaki I., Shimada T., Abe T.

Journal of Spacecraft and Rockets 47 巻 ( 4 ) 頁： 627 - 633 2010年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Spacecraft and Rockets

Under certain conditions during rocket flight, ionized exhaust plumes from solid rocket motors may interfere with RF transmission. To understand the relevant physical processes involved in this phenomenon, measurement of microwave attenuation and phase delay caused by rocket exhaust plumes was attempted in a sea-level static firing test for a full-scale solid propellant rocket motor. The measured data were analyzed by comparing them with simulation results for an exhaust plume flowfield. The results revealed that the change in the shock structure in the plume affects the microwave attenuation level, since it significantly affects the plasma density at the measuring location. When the plasma density in the plume is low, the microwaves can penetrate the plume. The plume plasma properties were successfully estimated for that situation in which the numerically calculated attenuation level agreed well with the experimental results. On the other hand, high-density plasma in the plume does not allow penetration. Therefore, microwaves bypass around the plume and the diffraction effect becomes dominant. Copyright © 2010 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

DOI： 10.2514/1.48173

Laser absorption velocimetry of plasma flow in two-dimensional magnetoplasmadynamic arcjet 査読有り

Kinefuchi K., Funaki I., Toki K.

Journal of Propulsion and Power 22 巻 ( 5 ) 頁： 1085 - 1090 2006年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Propulsion and Power

Experimental velocimetry in the discharge chamber of a two-dimensional magnetoplasmadynamic (MPD) arcjet, fabricated for experimental internal flow measurement, was conducted to investigate the acceleration process for hydrogen propellant. In the experiment, we evaluated the neutral atom velocity and the temperature from the laser absorption spectroscopy using a tunable diode laser. The results using two types of anode, a flared-tvpe anode and a converging-diverging (C-D)-type anode, were compared for the case with a discharge current of 13 kA and a mass-flow rate of 0.65 g/s. It was found that a large velocity slip between the ions and the neutrals prevented the acceleration of the neutral particles. This velocity slip is expected to reduce thrust performance because the flow with ion-neutral slip requires additional electric power compared to the flow without velocity slip. The velocity slip was reduced in the case of the C-D anode compared to the flared anode because of strong ion-neutral momentum coupling in the throat region of the C-D anode. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

DOI： 10.2514/1.17038

2次元型MPDアークジェットの速度場と電力収支計測査読有り

杵淵紀世志, 船木一幸, 都木恭一郎, 清水幸夫

日本航空宇宙学会論文集 53 巻 ( 616 ) 頁： 215 - 223 2005年

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：社団法人日本航空宇宙学会

Velocity and temperature measurements were conducted for a two-dimensional magnetoplasmadynamic arcjet with hydrogen propellant. To obtain the velocities of both atoms and ions, laser absorption spectroscopy was employed for atom, and time-of-flight technique was used for ions. In a quasi-steady operation at 13kA/0.65g/s, larger ions velocity (33km/s) than that of the atoms (13km/s) was found in the case of flared anode configuration, which implies that large mean free path between the ions and atoms prohibited momentum transfer from the ions to the neutral particles. This velocity differen...

DOI： 10.2322/jjsass.53.215

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