Variable-Mass Dynamics Implementation in Multi-Physics Environment for Reusable Launcher Simulations

One of the driving challenges in launcher Guidance and Control (G&C) design is the strong coupling between different disciplines such as propulsion, aerodynamics, actuators, and structures, which all have a multi-physics nature. Enabling a more efficient and accurate modeling of these multi-disciplinary interactions through the use of a multi-physics modeling approach is believed to be beneficial in expediting the design process, reducing the conservatism in the assumptions used by G&C design and thereby improving the launcher performance. In particular, the accurate modeling of time-varying propellant mass dynamics is an essential component during preliminary design studies since it might have an impact on the dynamical simulations that in turn influence the assessment and evaluation of the launcher performance and trade-off designs across disciplines. This paper presents the implementation of variable-mass dynamics towards the preliminary design and development of a dedicated multi-physics simulator, termed R2M2 (Rapid Reusable Launcher Simulation via Multi-physics Modelling), for multi-actuated vertical take-off vertical landing (VTVL) launch vehicles. The paper first recapitulates previous investigations on variable mass dynamics from relevant literature, including specific descriptions of the dynamical effects during translational and rotational motion. It further addresses the implementation of these dynamical effects within a multi-physics modeling environment and shows the impact of variable-mass dynamical effects on the rotational motion. The model implementation and analysis of results is performed using simple yet representative models of different burn types of propellants or engines which are commonly found in launch vehicle configurations

Time varying potential function control for constrained attitude tracking

No abstract available

Autonmous slew manoeuvring and attitude control using the potential function method

No abstract available

Optimal results for autonomous attitude control using the potential function method

No abstract available

Design and Development of R2M2 - A Multi-Physics Modeling Tool for Reusable Launch Vehicles

ABSTRACT Designing a guidance and control (G&C) system for vertical take-off/vertical landing (VTVL) reusable launch vehicles is a complex and time-consuming process that requires comprehensive simulators considering the relevant system dynamics for various mission scenarios. The Rapid Reusable Launcher Simulation via Multi-physics Modelling (R2M2) tool aims to streamline this process. Implemented in Simulink/Simscape, R2M2 adopts a multi-physics/multi-domain modeling approach, making it adaptable to simulate a wide range of mission scenarios, including different vehicle configurations and environmental conditions. The simulation model is automatically assembled by a dedicated routine based on user-defined parameters. This paper describes the design and implementation of the R2M2 tool, its functionalities, advantages, and disadvantages, and showcases its capabilities for the ascent of a two-stage launch vehicle as a benchmark scenario

DETECTION AND QUANTITATION IN RAT-TISSUES OF THE SUPERPARAMAGNETIC MAGNETIC-RESONANCE CONTRAST AGENT DEXTRAN MAGNETITE AS DEMONSTRATED BY ELECTRON-SPIN-RESONANCE SPECTROSCOPY

RATIONALE AND OBJECTIVES. The compound studied in this article is a superparamagnetic macromolecular complex of magnetite cores coated with hydrophilic dextran, which is under active investigation as a contrast agent for magnetic resonance imaging (MRI) in liver and spleen. The biodistribution of paramagnetic compounds is problematic and is usually studied by histochemical reactions or by radiolabeling the compound under study. The purpose of this article is to show how electron spin resonance (ESR) spectroscopy detects dextran magnetite (DM) particles in tissues. METHODS. DM injected intravenously in the experimental animal was detected in some reticulo-endothelial organs by ESR. The spectroscopic study was validated using electron microscopy and electron-probe microanalysis. RESULTS. DM exhibits an ESR spectrum; ESR delineated the distribution of DM distribution in liver, spleen, bone marrow, and blood as a function of time. The blood clearance was biphasic, dependent on the size of particles. CONCLUSIONS. ESR spectroscopy is a highly sensitive and reproducible method of studying DM distribution

Dynamics and control analysis during rendezvous in non-Keplerian Earth - Moon orbits

The paper describes the development of a framework capable of addressing some fundamental3 issues in the analysis of proximity operations between two spacecraft that are operating within a4 three-body model defined by two primaries and the spacecraft themselves. The main objective is5 to enable the capability of analysing dynamic and control issues during an automated rendezvous6 between a vehicle and a passive space station orbiting around the Earth - Moon L2 Lagrangian7 point on a near rectilinear halo orbit. The paper presents first a restricted three body model8 dynamics and a nominal approach trajectory, followed by an analysis of the influence of assumed9 actuators and sensors. Critical aspects such as selected failures are investigated, in order to10 ensure passive safety of the mission using impulsive maneuvers. An example of closed loop11 guidance in the near range is also presented and the overall performance are validated with an12 Ephemeris model available in the literatur

Documento di consenso e raccomandazioni per la prevenzione cardiovascolare in Italia 2018 [Consensus document and recommendations for the prevention of cardiovascular disease in Italy - 2018]

Cardiovascular prevention represents a cornerstone of modern strategies to reduce the burden of cardiovascular disease. It is of key importance to prevent cardiovascular diseases and associated events, not only to reduce morbidity and mortality, but also to increase the years of wellness in the aging population and to make the growing socio-economic burden imposed by cardiovascular events more sustainable.The current approach to prevention is based on an integrated use of effective lifestyle measures and, whenever appropriate, of antihypertensive and antidiabetic drugs, lipid-lowering agents and antiplatelet drugs.Given that population characteristics, in terms of ethnicity, demography and lifestyle habits, and healthcare system organizations differ among countries, international guidelines are not always applicable to specific countries and, often, are difficult to translate into daily clinical practice.In order to afford the specific features of Italy, 10 Scientific Societies and Research Institutions, mostly involved in preventive strategies, contributed to the present Italian consensus document, which includes brief, practical recommendations to support the preventive actions within the physician community and the general practice setting