Journal of Spacecraft and Rockets最新文献_第3页

Rankine Vortex Suppression Employing Shaped Drain Ports: Assessment Using a New Parameter 采用异形排水口抑制兰肯涡流：使用新参数进行评估

Journal of Spacecraft and Rockets Pub Date : 2024-05-12 DOI: 10.2514/1.a36036

M. Prabhu, R. Ajith Kumar

{"title":"Rankine Vortex Suppression Employing Shaped Drain Ports: Assessment Using a New Parameter","authors":"M. Prabhu, R. Ajith Kumar","doi":"10.2514/1.a36036","DOIUrl":"https://doi.org/10.2514/1.a36036","url":null,"abstract":"The phenomenon of vortexing is common in engineering applications but must be prevented due to its adverse effects on draining systems. Environmental disturbances often induce rotational motions in liquid propellants, leading to the formation of vortex air cores within the propellant tank. These air cores can impede the flow of propellants through the outlet, potentially compromising engine performance and jeopardizing mission success. The formation of air-core vortices can also induce cavitation problems in the feed pumps of propellant-draining systems. To address these challenges, researchers have designed innovative drain port geometries aimed at suppressing vortex formations. However, the lack of standardized metrics for evaluating vortexing hinders the comparison of findings across different studies. To overcome this issue, the present study formulates and proposes a novel parameter that integrates various parametric characterizations used in previous studies to assess vortexing. Upon analyzing the performance of different drain port shapes using this newly developed parameter, this study identifies cruciform drain ports with an aspect ratio of 3 as the most effective ones in suppressing vortexing. The current findings not only contribute to the data on vortex suppression strategies but also highlight the need for standardized metrics to evaluate vortexing.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"108 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140986719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Leveraging Large Language Models for Tradespace Exploration 利用大型语言模型探索贸易空间

Journal of Spacecraft and Rockets Pub Date : 2024-05-08 DOI: 10.2514/1.a35834

Gabriel Apaza, Daniel Selva

{"title":"Leveraging Large Language Models for Tradespace Exploration","authors":"Gabriel Apaza, Daniel Selva","doi":"10.2514/1.a35834","DOIUrl":"https://doi.org/10.2514/1.a35834","url":null,"abstract":"This paper proposes a method for leveraging large language models (LLMs) to improve the question-answering capabilities of artificial intelligence (AI) assistants for tradespace exploration. The method operates by querying an information space composed of fused data sources encompassing the tradespace exploration process and responding based on the gathered information. The information retrieval process is modeled as an internal dialog where an LLM-based dialog agent converses with a subquery answering agent. A case study is conducted on a next-generation soil moisture mission (SM-NG), and a generative AI assistant (named Daphne-G) is configured on it. The effect of the dialog agent and the choice of LLM are assessed by comparing the performance of three different system configurations on a validation question set. A second validation effort is conducted, comparing Daphne-G’s responses to those of a baseline template-based AI assistant, Daphne-VA. Results show that the dialog-based system is necessary for answering complex questions requiring multiple documents. Furthermore, results show that Daphne-G can correctly answer all the questions Daphne-VA can answer, while simultaneously being able to answer a greater number of questions than Daphne-VA. The results suggest that LLMs could significantly improve the outcomes of the tradespace exploration process, which may result in better and more cost-effective mission concepts being implemented.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":" 56","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141000372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Verification of a Modified Cylindrical Focused Laser Differential Interferometer 改进型圆柱聚焦激光差分干涉仪的实验验证

Journal of Spacecraft and Rockets Pub Date : 2024-04-25 DOI: 10.2514/1.a35842

K. Hopkins, Ramprakash Ananthapadmanaban, Timothy J. McIntyre, David J. Mee, Vincent Wheatley, A. Veeraragavan

{"title":"Experimental Verification of a Modified Cylindrical Focused Laser Differential Interferometer","authors":"K. Hopkins, Ramprakash Ananthapadmanaban, Timothy J. McIntyre, David J. Mee, Vincent Wheatley, A. Veeraragavan","doi":"10.2514/1.a35842","DOIUrl":"https://doi.org/10.2514/1.a35842","url":null,"abstract":"A modification to cylindrical focused laser differential interferometry (CFLDI) that, without beam intersection, can achieve smaller stand-off distances from flat geometries than conventional FLDI is presented. The modified system uses a cylindrical lens pair to expand and collimate the beam in a single direction, parallel to the model surface, forming a long, flat, elliptical profile. Subsequently, a spherical lens focuses the beam. Mach 7.3 hypersonic flow, produced by the T4 Stalker Reflected Shock Tunnel, was used for an experimental comparison between the responses of the modified CFLDI and a similar FLDI system in the freestream and just above the boundary-layer edge. Good agreement between the modified CFLDI and FLDI among all measured frequencies was observed when probing near the boundary-layer edge. The comparison in the freestream had good agreement up to 1500 kHz, and higher frequencies saw the modified CFLDI response attenuated at a shallower angle than the FLDI. A combination of different system parameters and base noise levels between the experiments is believed to account for this difference. The modified CFLDI system was used to probe inside the boundary layer, achieving a [Formula: see text] of approximately 0.4, where broadband turbulence is detected.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"92 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140654675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Calibration and Analysis of Entry Vehicle Radiometers 入境车辆辐射计的校准和分析

Journal of Spacecraft and Rockets Pub Date : 2024-04-25 DOI: 10.2514/1.a35947

B. Cruden

引用次数: 0

Superior Al90Mg10-Based Composite Fuel Grain for a Hybrid Rocket Engine 用于混合火箭发动机的优质铝基 90Mg10 复合燃料晶粒

Journal of Spacecraft and Rockets Pub Date : 2024-04-22 DOI: 10.2514/1.a35948

Zezhong Wang, Xin Lin, Junjie Pan, Jiaxiao Luo, Ruoyan Wang, Zelin Zhang, Xilong Yu

{"title":"Superior Al90Mg10-Based Composite Fuel Grain for a Hybrid Rocket Engine","authors":"Zezhong Wang, Xin Lin, Junjie Pan, Jiaxiao Luo, Ruoyan Wang, Zelin Zhang, Xilong Yu","doi":"10.2514/1.a35948","DOIUrl":"https://doi.org/10.2514/1.a35948","url":null,"abstract":"A paraffin-based fuel coupled with a nested helical matrix structure is a low-cost, high-performing alternative for hybrid rocket engine applications. The mechanical and combustion properties of the composite fuel grain can be enhanced by replacing the conventional polymer matrix with a metal skeleton. Three-dimensional printing was used to design an Al90Mg10 skeleton embedded with the paraffin-based fuel. The combustion characteristics of the composite fuel grain, including the ignition behavior, pressure oscillations, regression rate, and combustion efficiency, were comprehensively investigated. The properties of grains with and without a secondary perforated structure were compared. The flame structure and metal burning behavior of the hybrid rocket engine were monitored by endoscopic radioluminescence imaging, and the emission spectral characteristics of the plume were analyzed simultaneously. Good flammability makes the Al90Mg10 helical skeleton a promising candidate for enhancing the combustion performance of a paraffin-based fuel grain. The combustion process with rapid ignition was relatively stable, and no additional pressure oscillation frequency was observed. The metal-based composite fuel grains had a superior regression rate to that of a paraffin-based fuel grain (up to 100% higher using the perforated skeleton). Introducing a secondary structure into the fuel grain promoted the reaction and thereby enhanced the combustion performance.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"29 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140676164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Carrying Capacity of Low Earth Orbit Computed Using Source-Sink Models 利用源汇模型计算的低地球轨道运载能力

Journal of Spacecraft and Rockets Pub Date : 2024-04-10 DOI: 10.2514/1.a35729

Andrea D’Ambrosio, Richard Linares

{"title":"Carrying Capacity of Low Earth Orbit Computed Using Source-Sink Models","authors":"Andrea D’Ambrosio, Richard Linares","doi":"10.2514/1.a35729","DOIUrl":"https://doi.org/10.2514/1.a35729","url":null,"abstract":"The low-Earth-orbit (LEO) environment will likely experience an exponential growth of the anthropogenic space object population, also due to the many proposed large constellations, which could negatively affect the sustainability of the space environment if no proper regulatory actions are introduced. This paper introduces a methodology to analyze high-capacity sustainable solutions of the LEO region from 200 to 900 km altitude. Sustainability is assessed through the stable equilibrium points of a source-sink model called MIT Orbital Capacity Assessment Tool 3 (MOCAT-3). Capacity is estimated using an optimization procedure that aims to compute the optimal launch rate that maximizes the number of satellites in LEO, subject to a risk-rate constraint. Results show that the sustainable number of satellites increases with the risk rate constraint. Moreover, the resilience of the proposed solutions is tested against a more accurate time-varying atmospheric density model and perturbations of the initial equilibrium population. The compatibility of the proposed solutions with future traffic launches and a strategy to accommodate future traffic needs are presented. Limitations of the current work are discussed, chiefly the importance of validation of model coefficients and behavior before resulting capacity estimates are used to guide actual decision-making.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140717252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Uncertainty Quantification of Artemis I Space Launch System Integrated Aerodynamics Databases 阿耳特弥斯一号空间发射系统综合空气动力学数据库的不确定性量化

Journal of Spacecraft and Rockets Pub Date : 2024-04-10 DOI: 10.2514/1.a35844

Michael W. Lee, Patrick R. Shea, Jeremy T. Pinier, David T. Chan

引用次数: 0

Utilizing Artificial Neural Networks for Entry Vehicle Aerodynamic Characterization 利用人工神经网络进行入境车辆空气动力特性分析

Journal of Spacecraft and Rockets Pub Date : 2024-04-10 DOI: 10.2514/1.a35737

Zachary J. Ernst, Bradford Robertson, Dimitri Mavris

{"title":"Utilizing Artificial Neural Networks for Entry Vehicle Aerodynamic Characterization","authors":"Zachary J. Ernst, Bradford Robertson, Dimitri Mavris","doi":"10.2514/1.a35737","DOIUrl":"https://doi.org/10.2514/1.a35737","url":null,"abstract":"Determining the dynamic stability of blunt body entry vehicles is a persistent engineering challenge, particularly in the low supersonic to subsonic flight regime where the behavior of the unsteady wake is a primary contributor. Dynamic stability quantities are determined by fitting measurements of a ballistic range campaign or a computational fluid dynamics (CFD) computational experiment to an assumed functional form in order to regress quasi-static stability coefficients. However, this data reduction process has many implicit assumptions that may not hold. This paper explores novel alternatives to the established methods for modeling blunt body aerodynamics. A six-degree-of-freedom CFD-in-the-loop flight model is used to run “virtual ballistic range tests,” fully capturing the relevant flow physics. Feed-forward and time-delay neural network models are fitted to the time-series trajectory and aerodynamic results, which can then be used to predict aerodynamic forces and moments. These models do not have a prescribed functional form and do not assume linearized aerodynamics. The models are evaluated for goodness-of-fit in their aerodynamic and trajectory prediction. The feed-forward neural network model resulted in a better prediction of the virtual ballistic range tests than a traditional database. The time-delay network had good open-loop performance but suffered from closed-loop instability.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"2000 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140718763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design of Onboard Avionics Based on Commercial Off-the-Shelf Parts for TianQi-2 Nanosatellite 基于商用现成部件的天启二号超小型卫星星载航空电子设备设计

Journal of Spacecraft and Rockets Pub Date : 2024-04-05 DOI: 10.2514/1.a35743

Lianxiang Jiang, Wang Lei, Mingxiang Li, Zhang Teng, Peipei Xu

{"title":"Design of Onboard Avionics Based on Commercial Off-the-Shelf Parts for TianQi-2 Nanosatellite","authors":"Lianxiang Jiang, Wang Lei, Mingxiang Li, Zhang Teng, Peipei Xu","doi":"10.2514/1.a35743","DOIUrl":"https://doi.org/10.2514/1.a35743","url":null,"abstract":"With the development of modern small satellite technology, short development cycles, low cost, and high reliability have become trends in the era of New Space. To achieve the above goals, an integrated centralized architecture of onboard avionics for an internet of things CubeSat was proposed, and CAN, I2C, and 1-wire buses were employed for telemetry collection and command sending. The implementation of onboard computers (OBCs) and the power conditioning and distribution unit (PCDU) was introduced based on the PC104 industrial standards. An arbitration switching strategy between the primary and backup OBCs was proposed so that the primary OBC had priority to be on duty. Over 98% of commercial off-the-shelf (COTS) parts were used to decrease costs, so a procedure for COTS part selection and a qualified method were presented for reliable application. The onboard avionics, including OBC and PCDU, were developed in six months, and the satellite has been in orbit for more than three years and still works well. The reliability of the onboard avionics developed using the philosophy of New Space is demonstrated by the three-year flight in orbit.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"19 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140739172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low-Speed Space Launch System Computational Fluid Dynamics: A Comprehensive Overview 低速空间发射系统计算流体动力学：全面概述

Journal of Spacecraft and Rockets Pub Date : 2024-04-05 DOI: 10.2514/1.a35832

Brent Pomeroy, S. Krist, Thomas Wignall, Michael Lee, Karen Deere, Farhad Ghaffari

{"title":"Low-Speed Space Launch System Computational Fluid Dynamics: A Comprehensive Overview","authors":"Brent Pomeroy, S. Krist, Thomas Wignall, Michael Lee, Karen Deere, Farhad Ghaffari","doi":"10.2514/1.a35832","DOIUrl":"https://doi.org/10.2514/1.a35832","url":null,"abstract":"In this review paper, low-speed computational work from NASA Langley Research Center in support of the Space Launch System (SLS) is discussed. This information includes both historical and present efforts with the Kestrel computational fluid dynamics solver. The low-speed aerodynamics of SLS is highly complex, and the analysis of the unsteady flowfield requires significant computational efforts. The SLS mission profile varies from the vehicle static on the launch pad through high-speed ascent. This study focuses on the prelaunch as well as liftoff and transition portions of the flight both in proximity to the launch tower and in isolation. High-alpha conditions, as large as 90 deg, result in a flowfield dominated by massive, large-scale flow separation and asymmetric vortices. High-fidelity solutions require an unsteady computational formulation to accurately capture the aerodynamics of the vehicle. A detailed discussion of the computational approach is presented, followed by key efforts to support the program, both historic and present, including information that has been either published previously or that has never before been published external to NASA.","PeriodicalId":508266,"journal":{"name":"Journal of Spacecraft and Rockets","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140737039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0