Transactions of the Japan Society for Aeronautical and Space Sciences最新文献

{"title":"Abstracts of the Papers Published in Journal of the Japan Society for Aeronautical and Space Sciences (Vol. 69, No. 2, Apr. 2021)","authors":"","doi":"10.2322/tjsass.64.195","DOIUrl":"https://doi.org/10.2322/tjsass.64.195","url":null,"abstract":"","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68662942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Position and Attitude Tolerances of Carbon Nanotube Field Emission Cathode as a Neutralizer in an Ion Engine System","authors":"Jumpei Kinoshita, R. Ikeda, Misaki Adachi, Ryo Shiraki, T. Morita, N. Yamamoto, M. Nakano, Yasushi Ohkawa, I. Funaki","doi":"10.2322/tjsass.64.288","DOIUrl":"https://doi.org/10.2322/tjsass.64.288","url":null,"abstract":"Formation flight using small satellites offers low cost space applications, high resolution earth observation, observation of electromagnetic waves (X-ray, infrared, and so on) emitted from celestial objects or even observation of gravitational waves. The propulsion system requirements of these missions include large total impulse with low propellant and power consumption, high response speed, a 3 digit throttling range, and low thrust noise.1) Offering large total impulse with low propellant and power consumption, an ion engine with field emission cathode is suitable as a main propulsion system. For small satellite applications,2) power consumption is an important factor. A field emission cathode (FEC)3–6) is therefore an attractive candidate for the electron source, since it has lower power consumption than conventional cathodes (such as hollow cathodes, microwave discharge cathodes, or radio-frequency discharge cathodes) and it does not consume propellant. It also does not involve failure-prone parts, such as valves and mass flow controllers. The current density of an FEC assembly is small,7) on the order of several mA/cm2 and that demonstrated for on-orbit use is even smaller,8) about 60 LA/cm2. These features of the FEC provide a robust and compact system, and offer higher specific impulse than conventional systems. Conventional ion engines provide about 20–25% of their propellant to the cathodes,9–12) and this leads to 20–25% degradation of the specific impulse. In our previous work, the neutralization of an ion engine using xenon gas as a propellant with a field emission neutralizer was successfully demonstrated,2) though the electron emission cost was 360W/A, which is higher than that of a conventional hollow cathode (less than 30W/A).13) Small hollow cathodes, whose emission current is in the range of 10–100mA, consume several watts, which means that the electron emission cost of a small hollow cathode is more than 250W/A.14,15) Other remaining challenges in this field include investigation of cathode position and attitude tolerances, evaluation of thrust noise, and extension of the lifespan of the FEC with carbon nanotubes. The aim of the present study is to investigate the dependence of cathode position and attitude on neutralization performance, for the evaluation of the cathode setpoint tolerance. The potential difference between cathode and ground, Vcg, is used here as an indicator of neutralization. If Vcg drops below a critical voltage, the FEC will be sputtered by charged exchanged ions, and this could lead to degradation of emission capacity. For the purposes of the present study, the critical potential difference is taken to be120V, since the potential difference between the plume and the ground is assumed about 30V and the threshold energy of carbon-carbon composite under xenon bombardment is assumed to be about 50 eV.16) This critical value, 120V, a reasonable assumption for the present purposes, should be further investigate","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aerodynamic Characteristics of Busemann Biplane by Wake Measurements in Low-Speed Wind Tunnel","authors":"M. Kashitani, ThaiDuong Nguyen, K. Kusunose, M. Taguchi, Y. Takita","doi":"10.2322/tjsass.64.258","DOIUrl":"https://doi.org/10.2322/tjsass.64.258","url":null,"abstract":"In this study, the basic aerodynamic characteristics of a Busemann biplane model in a low-speed wind tunnel were clari fi ed by the wake survey technique. A low-speed wind tunnel of the blowdown type was used, and it had an exit nozzle size is in 1.5m © 1.5m. A wake measurement system and six-component balance system were installed in the test section. A fi ve-hole probe was used in the wake measurement system to measure the velocity distribution. The Busemann biplane model was designed to cruise at Mach 1.7. The total length of the model was 742mm, and the width was 556mm. The shape of the fuselage was 76mm square on a side, and the nose had a double-conical shape. The fl ow velocity was 20m / s, and the Reynolds number derived from the mean chord length was 1.4 © 10 5 . The results of the study are summarized as follows. Based on the visualization of the wake fl ow, vortices were generated from the tips of the upper and lower wing elements of the biplane at an attack angle of ¡ = 0°, but the vortices had an opposing rotation direction. Analysis of the wake data showed that locally induced drag was not generated at the wing tip. At ¡ = 6° and 8°, the pro fi le drag increased, probably due to the in fl uence of the fl ow separation from the upper surface of the upper wing element. However, the total lift coe ffi cient increased with an increasing angle of attack, even at ¡ > 8°. Therefore, it can be concluded that the biplane lift is mainly generated by the lower wing elements.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstracts of the Papers Published in Journal of the Japan Society for Aeronautical and Space Sciences (Vol. 69, No. 5, Oct. 2021)","authors":"","doi":"10.2322/tjsass.64.361","DOIUrl":"https://doi.org/10.2322/tjsass.64.361","url":null,"abstract":"","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance Evaluation of Combustion-controllable 0.1-N-Class Solid Propellant Microthrusters Using Laser Heating","authors":"Daichi Haraguchi, Shota Isakari, Yasuyuki Yano, Akira Kakami","doi":"10.2322/TJSASS.64.65","DOIUrl":"https://doi.org/10.2322/TJSASS.64.65","url":null,"abstract":"Conventional solid-propellant thrusters do not require tanks or valves and, accordingly, have high reliability and simple structures. Nevertheless, thrusters have not been applied to the attitude or station control of satellites because of prob-lems with throttling. We therefore propose a new combustion-controllable, solid propellant microthruster using laser heating. The proposed thruster uses combustion-controllable, hydroxyl-terminated polybutadiene / ammonium perchlorate solid propellant where combustion is maintained only while the burning surface is heated with a laser. Therefore, combustion is started and stopped by switching the laser heating. In a previous study, laser-switching was used to start and stop thrust production. Stable thrusts and combustion chamber pressures with a thrust and speci fi c impulse I sp of 0.02N and 95s, respectively, were obtained. However, fi ring tests showed an ignition delay of approximately 3s. In this study, to shorten the ignition delay, the diameter of carbon black (C) used to absorb the laser beam was reduced from 50 to 20 ® m. Thrust measurements showed that a º 20- ® m C was comparable to a º 50- ® m C in terms of the maximum I sp , and reduced ignition delay. Using a º 20- ® m C produces a shorter ignition delay and 120-s-class I sp by adjusting the laser-head traverse velocity.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"31 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sounding the Atmospheric Density at the Altitude of LARES and Ajisai during Solar Cycle 24","authors":"C. Padrini, L. Anselmo, D. Lucchesi, R. Peron, M. Bassan, C. Magnafico, G. Pucacco, M. Visco","doi":"10.2322/TJSASS.64.125","DOIUrl":"https://doi.org/10.2322/TJSASS.64.125","url":null,"abstract":"During Solar Cycle 24, the passive spherical satellites LARES and Ajisai, placed in nearly circular orbits with mean geodetic altitudes between 1450 and 1500 km, were used as powerful tools to probe the neutral atmosphere density and the performances of six thermospheric models in orbital regimes for which the role of dominant atomic species is contended by hydrogen and helium, and accurate satellite measurements are scarce. The starting point of the analysis was the accurate determination of the secular semi-major axis decay rate and the corresponding neutral drag acceleration in a satellite- centered orbital system. Then, for each satellite, thermospheric model and solar activity level, the drag coefficients capable of reproducing the orbital decay observed were found. These coefficients were finally compared with the physical drag coefficients computed for both satellites in order to assess the biases affecting the thermospheric density models. None of them could be considered unconditionally the best; the specific outcome depending on solar activity and the regions of the atmosphere crossed by the satellites. During solar maximum conditions, an additional density bias linked to the satellite orbit inclination was detected.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68662324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parametric Study on Waverider Configurations at Low-supersonic Speed for Low-boom Supersonic Transport","authors":"Potsawat Boonjaipetch, K. Shimoyama, S. Obayashi","doi":"10.2322/tjsass.64.325","DOIUrl":"https://doi.org/10.2322/tjsass.64.325","url":null,"abstract":"Research on supersonic transport seeks to overcome two main challenges, to mitigate sonic boom and improve aerodynamic performance, in order to become environmentally viable and economically practicable. To achieve these goals, this research proposes a waverider configuration to solve the challenge of designing commercial supersonic aircraft. The waverider is famous for providing a higher lift-to-drag ratio than that provided by other conventional designs for supersonic and hypersonic flights. The study of three types of supersonic waveriders, cone-derived, power-law, and osculatingcone waverider, is introduced for low-supersonic designs. The flight condition includes a speed of Mach 1.5 at an altitude of 18,000m. An unstructured grid with an inviscid Euler equation solver is used to calculate the flow field of the vehicle. The ground noise post-processing uses an augmented Burgers equation solver to assist in far-field signature evaluation. The result of a cone-derived waverider provided significant volume with low overpressure, while the power-law waverider showed the advantages of aerodynamic performance and ample design space. The osculating-cone waverider obtained the merits from both the cone-derived and power-law waveriders. The waverider is expected to have a quality that satisfies the design objectives of supersonic aircraft: high aerodynamic performance and sonic boom mitigation.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Added Masses of an Elliptical Cylinder with Unsteady Motion or in Unsteady Flow","authors":"Terukazu Tateno, S. Sunada","doi":"10.2322/tjsass.64.358","DOIUrl":"https://doi.org/10.2322/tjsass.64.358","url":null,"abstract":"2 f2: complex velocity potential H; V : velocities in x and y directions H0; V0: steady components in H; V H1; V1: amplitudes of unsteady components in H; V mij: added masses in i-direction under unsteady flow or unsteady motion in j-direction Rx; Ry: ratio of added masses in x and y directions t: time U: flow velocity having just x component U : flow velocity having x and y components X; Y : hydrodynamic forces in x and y directions z0: position of the center of an elliptical cylinder : angle between the long axis and x axis : circulation : flow density !: circular frequency","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68664169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Two-Hinged Wings","authors":"Shun Watanabe, S. Sunada, K. Yamaguchi","doi":"10.2322/tjsass.64.267","DOIUrl":"https://doi.org/10.2322/tjsass.64.267","url":null,"abstract":"Two types of wing geometries imitating wings of birds in gliding fl ight are analyzed with the vortex lattice method in terms of lift-drag ratio and root bending moment while varying the joint positions and joint angles under the constant lift coe ffi cient and constant fl ight velocity conditions. One geometry is, what is sometimes called, a gull wing which has a dihedral inner wing and horizontal outer wing, named “ DH wing. ” On the contrary, the other geometry is a drooped wing which has a horizontal inner wing and anhedral outer wing, named “ HA wing. ” The lift-drag ratio of the HA wing becomes larger when the joint of the anhedral outer wing is closer to the wing tip with a larger anhedral angle, while the root bending moment of the HA wing becomes smaller when the joint of the anhedral outer wing is closer to the wing root with a larger anhedral angle. In contrast, the DH wing has no combination of a joint position and joint angle to improve the lift-drag ratio, and it is found that the HA wing e ff ectively contributes to the reduction of the root bending moment and the lift-drag ratio compared with the DH wing.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flight Model Development and Ground Demonstration of Water Resistojet Propulsion System for CubeSats","authors":"K. Nishii, J. Asakawa, Kosei Kikuchi, Mariko Akiyama, Qihang Wang, Masaya Murohara, Yasuho Ataka, H. Koizumi, R. Funase, K. Komurasaki","doi":"10.2322/tjsass.63.141","DOIUrl":"https://doi.org/10.2322/tjsass.63.141","url":null,"abstract":"The University of Tokyo has proposed a water resistojet thruster with a high certainty of liquid – vapor separation and low power consumption. In this propulsion system, liquid water is periodically vaporized in a pulsating manner to generate thrust. A vaporization chamber with a labyrinth-shaped fl ow path catches droplets using their surface tension to separate the liquid and vapor, and the droplets vaporize under normal temperature to reduce the input power by reusing the heat from the surrounding components. In this study, we designed and fabricated a fl ight model of the proposed propulsion system for 6U CubeSat and evaluated the performance of this propulsion system, including the control method. The results con fi rm the concept of the proposed liquid – vapor separation method and its low power consumption. Moreover, we re-vealed the relationships between the vaporizing duty cycle, input power, and thrust.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"14 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68660495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}