Aerotecnica Missili & Spazio最新文献_第10页

Aerotecnica M&S 100 Years Ago: Air Navigation and Debate Between Airship and Airplane Aerotecnica M&S 100年前：航空导航与飞艇与飞机之争

Aerotecnica Missili & Spazio Pub Date : 2022-11-12 DOI: 10.1007/s42496-022-00142-5

Aldo Frediani

引用次数: 0

Numerical Simulations of Fuel Shape Change and Swirling Flows in Paraffin/Oxygen Hybrid Rocket Engines 石蜡/氧混合火箭发动机燃料形态变化及旋流的数值模拟

Aerotecnica Missili & Spazio Pub Date : 2022-10-20 DOI: 10.1007/s42496-022-00141-6

Marco Fabiani, Giorgio Gubernari, Mario Tindaro Migliorino, Daniele Bianchi, Francesco Nasuti

引用次数: 2

An Experimental and Numerical Study of the Aerodynamic Interaction Between Tandem Overlapping Propellers 串联重叠螺旋桨气动相互作用的实验与数值研究

Aerotecnica Missili & Spazio Pub Date : 2022-10-17 DOI: 10.1007/s42496-022-00138-1

Davide Algarotti

{"title":"An Experimental and Numerical Study of the Aerodynamic Interaction Between Tandem Overlapping Propellers","authors":"Davide Algarotti","doi":"10.1007/s42496-022-00138-1","DOIUrl":"10.1007/s42496-022-00138-1","url":null,"abstract":"<div><p>The latest trends of Urban Air Mobility pushed the aeronautical industrial sector towards the eVTOL concept, i.e. electrical vertical take-off and landing. Electrical power, tilt-wing configuration and multiple propellers in tandem configuration, i.e. with the propellers placed one after the other, are the key features of such concept. In particular, the presence of multiple propellers working at close range introduces a new challenge: the investigation of the rotor-rotor aerodynamic interaction between front propeller slipstreams and rear propellers. This topic is rather new, thus a lack of experimental literature is noticed. The present work aims to partially fill the gap through an extensive experimental activity which investigates the main physical aspects of the phenomenon in a typical eVTOL configuration. A dedicated wind tunnel testing campaign is performed to investigate deeply the interaction between two co-rotating tandem propellers at fixed axial distance and variable lateral separation. The performance of the tandem propellers were compared with an isolated configuration both in terms of thrust and torque measurements and Particle Image Velocimetry (PIV) surveys. The experimental results are the first step in the creation of a reference database for the validation of numerical codes implemented during the design phase of such vehicles. Load measurements showed a significant loss in the rear propeller performance as a function of the overlapping ratio between the propellers. Furthermore a dedicated spectral analysis of wind tunnel thrust signals outlined high amplitude fluctuations in partial overlapping configurations. In parallel a numerical activity was performed using a mid-fidelity aerodynamic solver relying upon Vortex Particle Method (VPM) in order to enhance the comprehension of the phenomenon. The analysis of the numerical results allowed to access the flow behaviour involving the front propeller slipstream and the rear propeller disk, which is responsible of the massive losses experienced by the rear propeller.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"102 1","pages":"77 - 89"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50035054","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: 1

A Novel Visual-Based Terrain Relative Navigation System for Planetary Applications Based on Mask R-CNN and Projective Invariants 基于Mask R-CNN和投影不变量的行星地形相对导航系统

Aerotecnica Missili & Spazio Pub Date : 2022-10-15 DOI: 10.1007/s42496-022-00139-0

Roberto Del Prete, Alfredo Renga

{"title":"A Novel Visual-Based Terrain Relative Navigation System for Planetary Applications Based on Mask R-CNN and Projective Invariants","authors":"Roberto Del Prete, Alfredo Renga","doi":"10.1007/s42496-022-00139-0","DOIUrl":"10.1007/s42496-022-00139-0","url":null,"abstract":"<div><p>In the framework of autonomous spacecraft navigation, this manuscript proposes a novel vision-based terrain relative navigation (TRN) system called FederNet. The developed system exploits a pattern of observed craters to perform an absolute position measurement. The obtained measurements are thus integrated into a navigation filter to estimate the spacecraft state in terms of position and velocity. Recovering crater locations from elevation imagery is not an easy task since sensors can generate images with vastly different appearances and qualities. Hence, several problems have been faced. First, the crater detection problem from elevation images, second, the crater matching problem with known craters, the spacecraft position estimation problem from retrieved matches, and its integration with a navigation filter. The first problem was countered with the robust approach of deep learning. Then, a crater matching algorithm based on geometric descriptors was developed to solve the pattern recognition problem. Finally, a position estimation algorithm was integrated with an Extended Kalman Filter, built with a Keplerian propagator. This key choice highlights the performance achieved by the developed system that could benefit from more accurate propagators. FederNet system has been validated with an experimental analysis on real elevation images. Results showed that FederNet is capable to cruise with a navigation accuracy below 400 meters when a sufficient number of well-distributed craters is available for matching. FederNet capabilities can be further improved with higher resolution data and a data fusion integration with other sensor measurements, such as the lunar GPS, nowadays under investigation by many researchers.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"101 4","pages":"335 - 349"},"PeriodicalIF":0.0,"publicationDate":"2022-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42496-022-00139-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50485578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Autonomous Wheel Off-Loading Strategies for Deep-Space CubeSats 深空立方体卫星的自主车轮卸载策略

Aerotecnica Missili & Spazio Pub Date : 2022-09-26 DOI: 10.1007/s42496-022-00137-2

Andrea Pizzetti, Antonio Rizza, Francesco Topputo

{"title":"Autonomous Wheel Off-Loading Strategies for Deep-Space CubeSats","authors":"Andrea Pizzetti, Antonio Rizza, Francesco Topputo","doi":"10.1007/s42496-022-00137-2","DOIUrl":"10.1007/s42496-022-00137-2","url":null,"abstract":"<div><p>Deep-space CubeSats missions require careful trade-offs on design drivers such as mass, volume, and cost, while ensuring autonomous operations. This work elaborates the possibility of off-loading the reaction wheels without the need of carrying a bulky and expensive reaction control system or the field-dependent magnetotorquers. The momentum accumulated along two body axes can be removed by either offsetting the main thruster with a gimbal mechanism or by tilting differentially the solar wings. The dumping on the third axis can be still accomplished by imposing a specific attitude trajectory with the motion of either the gimbal or the arrays drive mechanism. The M-Argo CubeSat is selected as case study to test the techniques along its deep-space trajectory. The strategies decision-making is autonomously carried out by a state machine. The off-loading during the cruising arcs employs the gimballed thruster and takes typically 3 h, granting a mass savings of more than 99% with respect to the usage of a reaction control system. The trajectory is shown to have negligible differences with respect to the nominal one, since the thrust is corrected accordingly. During the coasting arcs, the solar arrays are tilted and several hours are required, depending on the Sun direction and intensity, but the propellant is completely saved. Sensitivity analyses are also carried out on the initial angular momentum components and the center of mass displacement to check the robustness of the algorithms.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"102 1","pages":"3 - 15"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42496-022-00137-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50516654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical and Numerical Modeling of Multicomponent Transcritical Diffuse Interfaces Under LRE Conditions LRE条件下多组分跨临界扩散界面的理论和数值模拟

Aerotecnica Missili & Spazio Pub Date : 2022-09-10 DOI: 10.1007/s42496-022-00136-3

Davide Cavalieri

{"title":"Theoretical and Numerical Modeling of Multicomponent Transcritical Diffuse Interfaces Under LRE Conditions","authors":"Davide Cavalieri","doi":"10.1007/s42496-022-00136-3","DOIUrl":"10.1007/s42496-022-00136-3","url":null,"abstract":"<div><p>In this study, a theoretical and numerical framework for simulating transcritical flows under a variety of conditions of interest for aerospace propulsion applications is presented. A real-fluid multicomponent and multiphase thermodynamic model, based on a cubic equation of state (EoS) and vapor–liquid equilibrium (VLE) assumptions, is presented to describe transcritical mixtures properties. The versatility of this thermodynamic model is reported since it can represent at the same time the supercritical states as well as subcritical stable two-phase states at equilibrium, via a homogeneous mixture approach. The effect this model has on the evaluation of the thermophysical variables will be emphasized. From the Computational Fluid Dynamics (CFD) point of view, the well-known numerical challenges that arise with the coupling between real-fluid thermodynamics and governing equations under transcritical conditions, are addressed by comparing a fully conservative (FC) to a quasi-conservative (QC) numerical schemes, in the context of the advection problem of a transcritical contact discontinuity.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"102 1","pages":"45 - 57"},"PeriodicalIF":0.0,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42496-022-00136-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50470010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cassini Bistatic Radar Experiments: Preliminary Results on Titan’s Polar Regions 卡西尼双基地雷达实验：泰坦极地的初步结果

Aerotecnica Missili & Spazio Pub Date : 2022-09-10 DOI: 10.1007/s42496-022-00135-4

Giancorrado Brighi

{"title":"Cassini Bistatic Radar Experiments: Preliminary Results on Titan’s Polar Regions","authors":"Giancorrado Brighi","doi":"10.1007/s42496-022-00135-4","DOIUrl":"10.1007/s42496-022-00135-4","url":null,"abstract":"<div><p>In bistatic radar observations, reflected echoes from the surface of a target planet can be analyzed to infer its surface statistics and near-surface constituents. In this work, a preliminary inspection of two X-band bistatic radar observations gathered by the Cassini spacecraft about Titan’s polar regions is presented. Profiles of relative dielectric constant and root-mean-square (rms) surface slope are provided as outputs of the analysis, discussed, and compared with the present knowledge of Titan geomorphology. For the assessment of the rms slope, proportional to the spectral broadening of reflected echoes, a basic fitting procedure was applied to the received spectra using a Gaussian template, to later evaluate the full-width half-maximum of the fitting curve. The dielectric constant was computed from the power ratio between orthogonally circularly polarized components of signal reflections from Titan. Dielectric constant estimates are, on average, consistent with the expected materials covering the dry surfaces of the planet, while slightly low values were found over the seas. The rms slopes are generally low compared to past bistatic observations of other targets. Titan’s north polar seas are revealed to feature an unprecedented smoothness, with 0.01<span>(^circ)</span> of slope as an upper bound. Similar values were inferred for isolated spots in the southern pole, hinting at the possible presence of basins filled with liquid hydrocarbons. The main issues with the analysis are emphasized throughout the document, and some ideas for future work are presented in the conclusions.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"102 1","pages":"59 - 76"},"PeriodicalIF":0.0,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42496-022-00135-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50470475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

YORP Effect on Long-Term Rotational Dynamics of Debris in GEO YORP效应对地球同步轨道碎片长期旋转动力学的影响

Aerotecnica Missili & Spazio Pub Date : 2022-09-03 DOI: 10.1007/s42496-022-00134-5

Francesco Cuomo

{"title":"YORP Effect on Long-Term Rotational Dynamics of Debris in GEO","authors":"Francesco Cuomo","doi":"10.1007/s42496-022-00134-5","DOIUrl":"10.1007/s42496-022-00134-5","url":null,"abstract":"<div><p>The Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect describes the torque induced on space objects produced by solar radiation and thermal re-emission. Previous analyses have demonstrated its influence on long-term rotational dynamics of space debris objects in Geostationary Orbit (GEO), where YORP becomes predominant with respect to other external perturbations (e.g., atmospheric drag, gravity gradient, eddy current torque), leading to a wide variety of possible behaviors. The capability of forecasting time windows of slow uniform rotation, if any, would bring significant advantages in operations of Active Debris Removal and on-orbit servicing, especially in the detumbling phase. Also, a non-negligible impact of the End-of-Life configuration, in terms of movable surfaces orientation and center of mass location, could lead to guidelines for future satellites to be easier targets in the disposal phase. In this work, a previously derived semi-analytical tumbling-averaged YORP rotational dynamics model is leveraged. Exploiting an averaged model, computational time is strongly reduced while maintaining sufficient accuracy compared to propagation of Euler’s equations of motion. First, a satellite of the Geostationary Operational Environmental Satellite (GOES) family is analyzed and compared to previous studies to verify the correct implementation of the model. A wider analysis is performed on simple geometric models, such as a box-wing satellite, a 3U CubeSat, and a rocket body. The impact of object size, surface optical properties, and center of mass position on long-term rotational behavior is investigated, providing a general insight into these phenomena with a possible future application to existing objects in GEO.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"102 1","pages":"29 - 43"},"PeriodicalIF":0.0,"publicationDate":"2022-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42496-022-00134-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50446886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

3D Printing Techniques for Paraffin-Based Fuel Grains 石蜡基燃料颗粒的3D打印技术

Aerotecnica Missili & Spazio Pub Date : 2022-09-01 DOI: 10.1007/s42496-022-00126-5

Riccardo Gelain, Artur Elias De Morais Bertoldi, Adrien Hauw, Patrick Hendrick

{"title":"3D Printing Techniques for Paraffin-Based Fuel Grains","authors":"Riccardo Gelain, Artur Elias De Morais Bertoldi, Adrien Hauw, Patrick Hendrick","doi":"10.1007/s42496-022-00126-5","DOIUrl":"10.1007/s42496-022-00126-5","url":null,"abstract":"<div><p>Hybrid rocket propulsion systems have proved to be a suitable option for some specific applications in the space transportation domain such as in launch vehicle upper stages, orbit transfer spacecrafts, decelerator engines for re-entry capsules, and small satellites launchers. Part of the renewed interest in hybrid rocket propulsion is due mainly to the safety aspects, cost reduction, and the use of paraffin-based fuel that impacts positively in terms of the solid fuel regression rate. However, paraffin solid fuel grains have poor structural characteristics and sometimes low performance due to the fuel internal ballistics behaviour. More recently, various studies have been carried out to overcome these drawbacks of paraffin-based fuels, such as the addition of energetic nano-sized metallic powder and 3D printing techniques. This study presents a review of the principal concepts of 3D printing processes and extrusion techniques that can be suitable for paraffin grains manufacturing and the conceptual design of a prototype for a 3D printer system under development at the Aero-Thermo-Mechanics Department of Université Libre de Bruxelles.</p></div>","PeriodicalId":100054,"journal":{"name":"Aerotecnica Missili & Spazio","volume":"101 3","pages":"257 - 266"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42496-022-00126-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50001499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Challenges and Opportunities of Green Propellants and Electric Pump Feeding for Future European Kick Stages 绿色推进剂和电动泵给料对未来欧洲踢球阶段的挑战和机遇

Aerotecnica Missili & Spazio Pub Date : 2022-08-23 DOI: 10.1007/s42496-022-00133-6

L. Ordonez Valles, L. Blondel Canepari, U. Apel, M. Tajmar, A. Pasini

引用次数: 2