Monte Carlo simulation (MCS) has been widely applied in the preflight evaluation of flight systems because of advantages such as its ability to evaluate nonlinear systems with uncertain parameters, which are incorporated into MCS randomly and simultaneously. Some aerodynamic and control derivatives can have significant effects on flight control and vehicle performance, so it is important to evaluate the influences of their uncertainties. However, it has not been easy to incorporate uncertainties of derivatives into MCS appropriately. A derivative is the slope of a curve, such as the Cm–α curve. To randomly vary it for use in MCS, the rotation point on the curve must be determined. However, the deviation from the nominal curve becomes greater as the flight condition, such as α, moves further from the rotation point, which can result in excessive variance of the aerodynamic coefficient. This paper presents a new method to generate derivative and bias uncertainties randomly using a covariance matrix of uncertain parameters. The method is applied to the MCS of an existing experimental flight system, and the MCS results are compared with a result that excludes derivative uncertainties to show how to apply the presented method.
蒙特卡罗仿真(Monte Carlo simulation, MCS)由于能够对具有不确定参数的非线性系统进行随机、同步评估等优点，在飞行系统的飞前评估中得到了广泛的应用。一些气动导数和控制导数会对飞行器的飞行控制和性能产生重大影响，因此评估它们的不确定性对飞行器的影响具有重要意义。然而，将衍生品的不确定性适当地纳入MCS并不容易。导数是曲线的斜率，例如Cm -α曲线。为了在MCS中随机改变它，必须确定曲线上的旋转点。然而，随着飞行条件(如α)离旋转点越远，与标称曲线的偏差越大，这可能导致气动系数的方差过大。本文提出了一种利用不确定参数的协方差矩阵随机产生导数不确定性和偏置不确定性的新方法。将该方法应用于现有实验飞行系统的MCS，并将MCS结果与排除导数不确定性的结果进行了比较，以说明该方法的应用。
{"title":"Random Generation of Aerodynamic Derivatives for Monte Carlo Evaluation","authors":"Toshikazu MOTODA","doi":"10.2322/tjsass.66.187","DOIUrl":"https://doi.org/10.2322/tjsass.66.187","url":null,"abstract":"Monte Carlo simulation (MCS) has been widely applied in the preflight evaluation of flight systems because of advantages such as its ability to evaluate nonlinear systems with uncertain parameters, which are incorporated into MCS randomly and simultaneously. Some aerodynamic and control derivatives can have significant effects on flight control and vehicle performance, so it is important to evaluate the influences of their uncertainties. However, it has not been easy to incorporate uncertainties of derivatives into MCS appropriately. A derivative is the slope of a curve, such as the Cm–α curve. To randomly vary it for use in MCS, the rotation point on the curve must be determined. However, the deviation from the nominal curve becomes greater as the flight condition, such as α, moves further from the rotation point, which can result in excessive variance of the aerodynamic coefficient. This paper presents a new method to generate derivative and bias uncertainties randomly using a covariance matrix of uncertain parameters. The method is applied to the MCS of an existing experimental flight system, and the MCS results are compared with a result that excludes derivative uncertainties to show how to apply the presented method.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134982296","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}
A passively adaptive variable rotor diameter is proposed to improve the flight performance of variable-speed rotors. A validated helicopter model to predict rotor performance is utilized. The analyses focus on three typical flight states (i.e., hover, cruise, high speed) to explore the potential of the passively adaptive variable rotor diameter in reducing rotor power. During hover, the variable rotor diameter can optimize the distribution of lift and then reduce the rotor power, especially at lower rotor speeds. At a cruise speed of 150 km/h, the variable rotor diameter can delay stalling and reduce the rotor power, especially at lower rotor speeds. At a high speed of 300 km/h, the rotor speed needs to be increased, and the reduced rotor diameter is beneficial reducing power. The reduced power comes from decreasing the parasitic power of the fuselage due to decreasing its longitudinal tilt, and the rotor profile power and induced power increase with relatively small magnitudes. The passively adaptive variable rotor diameter is more suitable for larger take-off weights, and can effectively delay stalling at lower rotor speeds. The strategy of varying the rotor diameter can be designed according to the performance improvement requirements.
{"title":"Passively Adaptive Variable Rotor Diameter to Improve the Flight Performance of Variable-speed Rotors","authors":"Dong HAN, Dongxia XU, Long HE, Mingqi HUANG","doi":"10.2322/tjsass.66.226","DOIUrl":"https://doi.org/10.2322/tjsass.66.226","url":null,"abstract":"A passively adaptive variable rotor diameter is proposed to improve the flight performance of variable-speed rotors. A validated helicopter model to predict rotor performance is utilized. The analyses focus on three typical flight states (i.e., hover, cruise, high speed) to explore the potential of the passively adaptive variable rotor diameter in reducing rotor power. During hover, the variable rotor diameter can optimize the distribution of lift and then reduce the rotor power, especially at lower rotor speeds. At a cruise speed of 150 km/h, the variable rotor diameter can delay stalling and reduce the rotor power, especially at lower rotor speeds. At a high speed of 300 km/h, the rotor speed needs to be increased, and the reduced rotor diameter is beneficial reducing power. The reduced power comes from decreasing the parasitic power of the fuselage due to decreasing its longitudinal tilt, and the rotor profile power and induced power increase with relatively small magnitudes. The passively adaptive variable rotor diameter is more suitable for larger take-off weights, and can effectively delay stalling at lower rotor speeds. The strategy of varying the rotor diameter can be designed according to the performance improvement requirements.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134982452","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}
Jiyeon WOO, JinHyeok JANG, Dana PARK, Sangkyung SUNG, Young Jae LEE
At present, Global Navigation Satellite System (GNSS) satellites operate in medium Earth orbits (MEOs), geostationary orbits (GEOs), or inclined geosynchronous orbits (IGSOs). The QZSS consists of GEO and IGSO satellites. When we considering the QZSS skyplot in Japan and its surrounding areas, there are no satellites in the northern sky. This results in a geometric placement imbalance, and thereby, causes position errors. The fundamental method to solve this problem is to position a satellite in the vacant northern area. Therefore, in this research, the addition of navigation satellites with a high-inclination, high-eccentricity orbit (a new type of orbit) is proposed. The vacant northern area can be filled effectively by adding a satellite using this orbit. Three satellites with this orbit were added to the QZSS in a simulation. Thereby, satellites were positioned effectively in the vacant northern area of the skyplot for Tokyo and Seoul. In addition, the improvement in performance was verified quantitatively through Horizontal Dilution of Precision (HDOP) and Vertical Dilution of Precision (VDOP). Accordingly, the addition of a satellite with a high-inclination, high-eccentricity orbit to the QZSS would enable more accurate positioning in Japan and its surrounding areas.
{"title":"Addition of High-inclination, High-eccentricity Orbit Satellites to Improve QZSS Performance","authors":"Jiyeon WOO, JinHyeok JANG, Dana PARK, Sangkyung SUNG, Young Jae LEE","doi":"10.2322/tjsass.66.244","DOIUrl":"https://doi.org/10.2322/tjsass.66.244","url":null,"abstract":"At present, Global Navigation Satellite System (GNSS) satellites operate in medium Earth orbits (MEOs), geostationary orbits (GEOs), or inclined geosynchronous orbits (IGSOs). The QZSS consists of GEO and IGSO satellites. When we considering the QZSS skyplot in Japan and its surrounding areas, there are no satellites in the northern sky. This results in a geometric placement imbalance, and thereby, causes position errors. The fundamental method to solve this problem is to position a satellite in the vacant northern area. Therefore, in this research, the addition of navigation satellites with a high-inclination, high-eccentricity orbit (a new type of orbit) is proposed. The vacant northern area can be filled effectively by adding a satellite using this orbit. Three satellites with this orbit were added to the QZSS in a simulation. Thereby, satellites were positioned effectively in the vacant northern area of the skyplot for Tokyo and Seoul. In addition, the improvement in performance was verified quantitatively through Horizontal Dilution of Precision (HDOP) and Vertical Dilution of Precision (VDOP). Accordingly, the addition of a satellite with a high-inclination, high-eccentricity orbit to the QZSS would enable more accurate positioning in Japan and its surrounding areas.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134982435","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}
Marco GOMEZ-JENKINS, Julio CALVO-ALVARADO, Adolfo CHAVES-JIMÉNEZ, Johan CARVAJAL-GODÍNEZ, Esteban MARTINEZ, Yeiner ARIAS, Ana Julieta CALVO-OBANDO, Vladimir JIMENEZ, Juan José ROJAS, Alfredo VALVERDE-SALAZAR, Julio RAMIREZ-MOLINA
Project Irazú was an innovative space mission that aimed to propel the advancement of the aerospace sector in Costa Rica, by developing a ground to space communication solution for daily monitoring of carbon fixation in forests and tree plantations. Irazú is Central America’s first satellite mission and is a joint endeavor between the Central American Association of Aeronautics and Space and the Costa Rica Institute of Technology, along with national and international partners. The 1U CubeSat developed in this project was deployed from the International Space Station on May 2018, commencing straightaway operations. The scientific mission demonstrated a practical novel solution to monitor daily tree growth by using wireless electronic sensors and a store and forward satellite link. This article presents an overview of the project, along with the mission architecture, summary of the Assembly, Integration and Testing (AI&T) and operations phases, and results from the scientific mission, including the sensor’s performance and measurements of the daily estimated tree diameter during six months. The impacts that the project had on an emerging space nation such as Costa Rica is included as well.
{"title":"Project Irazú: Space and Ground Systems Engineering of a 1U CubeSat Store and Forward Mission for Environmental Monitoring","authors":"Marco GOMEZ-JENKINS, Julio CALVO-ALVARADO, Adolfo CHAVES-JIMÉNEZ, Johan CARVAJAL-GODÍNEZ, Esteban MARTINEZ, Yeiner ARIAS, Ana Julieta CALVO-OBANDO, Vladimir JIMENEZ, Juan José ROJAS, Alfredo VALVERDE-SALAZAR, Julio RAMIREZ-MOLINA","doi":"10.2322/tjsass.66.217","DOIUrl":"https://doi.org/10.2322/tjsass.66.217","url":null,"abstract":"Project Irazú was an innovative space mission that aimed to propel the advancement of the aerospace sector in Costa Rica, by developing a ground to space communication solution for daily monitoring of carbon fixation in forests and tree plantations. Irazú is Central America’s first satellite mission and is a joint endeavor between the Central American Association of Aeronautics and Space and the Costa Rica Institute of Technology, along with national and international partners. The 1U CubeSat developed in this project was deployed from the International Space Station on May 2018, commencing straightaway operations. The scientific mission demonstrated a practical novel solution to monitor daily tree growth by using wireless electronic sensors and a store and forward satellite link. This article presents an overview of the project, along with the mission architecture, summary of the Assembly, Integration and Testing (AI&T) and operations phases, and results from the scientific mission, including the sensor’s performance and measurements of the daily estimated tree diameter during six months. The impacts that the project had on an emerging space nation such as Costa Rica is included as well.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134982442","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}
Y. Inoue, T. Nishitani, Anna Honda, D. Sato, H. Shikano, A. Koizumi, Y. Honda, D. Ichihara, A. Sasoh
{"title":"Investigation on Applying an InGaN Photocathode with Negative Electron Affinity for Electric Propulsion","authors":"Y. Inoue, T. Nishitani, Anna Honda, D. Sato, H. Shikano, A. Koizumi, Y. Honda, D. Ichihara, A. Sasoh","doi":"10.2322/tjsass.66.10","DOIUrl":"https://doi.org/10.2322/tjsass.66.10","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":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68665572","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}
Tomohiro Mamashita, Tomotaro Muto, K. Kitamura, S. Nonaka
{"title":"Numerical Analysis on Axial Force Characteristics of Reusable Launch Vehicle at 150–180° Angles of Attack","authors":"Tomohiro Mamashita, Tomotaro Muto, K. Kitamura, S. Nonaka","doi":"10.2322/tjsass.66.118","DOIUrl":"https://doi.org/10.2322/tjsass.66.118","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":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68665725","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}
Qiang Zhang, Y. Tamanoi, D. Kang, K. Nishibe, K. Yokota, Kotaro Sato
{"title":"Influence of Amplitude of Excited Secondary Flow on the Direction of Jets","authors":"Qiang Zhang, Y. Tamanoi, D. Kang, K. Nishibe, K. Yokota, Kotaro Sato","doi":"10.2322/tjsass.66.37","DOIUrl":"https://doi.org/10.2322/tjsass.66.37","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":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68666221","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}
K. Ishihara, Kentaro Yoneyama, Tomoki Sato, Hiroaki Watanabe, Noboru Itouyama, A. Kawasaki, K. Matsuoka, J. Kasahara, A. Matsuo, I. Funaki
{"title":"Visualization and Performance Evaluation of a Liquid-Ethanol Cylindrical Rotating Detonation Combustor","authors":"K. Ishihara, Kentaro Yoneyama, Tomoki Sato, Hiroaki Watanabe, Noboru Itouyama, A. Kawasaki, K. Matsuoka, J. Kasahara, A. Matsuo, I. Funaki","doi":"10.2322/tjsass.66.46","DOIUrl":"https://doi.org/10.2322/tjsass.66.46","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":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68665851","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":"Fast Prediction of Two-Dimensional Flowfields with Fuel Injection into Supersonic Crossflow via Deep Learning","authors":"Kento Akiyama, Hideaki Ogawa","doi":"10.2322/tjsass.66.164","DOIUrl":"https://doi.org/10.2322/tjsass.66.164","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":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68666103","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":"Regression-Rate Evaluation of Hybrid-Rocket Fuel Grain with a Star-Fractal Swirl Port","authors":"Y. Funami, Atsushi Takano","doi":"10.2322/tjsass.66.61","DOIUrl":"https://doi.org/10.2322/tjsass.66.61","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":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68665890","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}
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