Particle Size in SRM Plume: Assessment of Collection Method

The present work aims at giving an overview of the current experimental activity status of an intrusive technique for particles capturing in supersonic-high temperature flows for the use in solid rocket motors plume. The innovative technique was conceived in the EMAP (Experimental Modelling of Alumina Particulate in Solid Booster) framework, an initiative financed by the European Space Agency aiming at the characterization of the alumina exiting from rocket nozzles in terms of size, temperature, and spatial distribution. This kind of information are of paramount importance for the environmental impact assessment of space launch activity. Experimental tests are still ongoing and the present paper discusses some of the critical aspects, solutions, and open questions arising during the hot fire testing of this innovative intrusive technique

Overview of a supersonic probe for solid propellant rocket CCP collection

The present work aims at giving a comprehensive overview of the current development status of an intrusive probe, capable of collecting the condensed combustion products present in the exhaust of a solid rocket motors. The innovative technique was conceived in the EMAP (Experimental Modelling of Alumina Particulate in Solid Booster) framework, a project aiming at characterizing the alumina in terms of size, temperature and spatial distribution to gain detailed information for climatological impact assessment. A supersonic probe was sized to handle a progressive deceleration and cooling of the exhaust gas, as well as the quenching and collection of the suspended particles in a pressure-controlled chamber. The task was achieved by through a quasi 1D gas dynamics code based on the Shapiro method and the normal shock wave theory, which was verified against a hybrid 2D axial-symmetric mesh whose turbulent flow field was solved using the DLR-TAU CFD code. The robustness of the system has been investigated performing a sensitivity and an uncertainty analysis, exploring uncertainties propagation through the numerical code based on Shapiro equations. The sensitivity analysis enabled to define a ranking of importance for the uncertainties on the probe behavior; the uncertainty analysis allowed to estimate failures of the system and/or of the code. Cold flow tests carried out at the vertical facility of DLR-Cologne enabled to gain a proof of concept for both fluid dynamic behavior and collection methodology

Particle Size in Solid Rocket Motor Plume: New Experimental Method

Solid propellant rocket boosters release metal oxide particulate in the atmosphere, as a result of the combustion of the aluminum powder contained in the energetic material. The characterization of these particles is still an open question regarding the environmental impact of space launch activities. For this reason an innovative collection technique was conceived in the frame of the EMAP (Experimental Modelling of Alumina Particulate in Solid Booster) project, an activity financed by the European Space Agency. The method consists in an intrusive probe capable of quenching and capturing the particles exiting from the nozzle, thus enabling size measurement, chemical characterization, and morphology observation. This paper presents an overview of the activity and reports some preliminary results obtained from the initial particle size characterization

Conceptual Design of the High-Speed Propelled Experimental Flight Test Vehicle HEXAFLY

A concise overview of the overall layout of an experimental powered high-speed flight vehicle including its subsystems is given. A mission scenario, the different flight segments and events to which the payload is exposed are described and justified. This allowed the definition of the aero-thermo-mechanical loads required to conceptually design all elements on board of the vehicle. The final vehicle configuration could achieve the different mission objectives. In particular an aero-propulsive balance, i.e. thrust ≥ drag and lift ≥ weight, could be established at a cruise Mach number of M = 7.4 on the basis of a hydrogen powered scramjet engine while guaranteeing a good aerodynamic efficiency L/D ≥ 4 in a stable, trimmed and controlled way. The experimental combustion campaign could last for at least for 3s up to 9s pending on the finally obtained flight level. This test time is very valuable as it is about 3 orders of magnitude higher of what can be tested in European ground facilities. The vehicle made maximum use of databases, expertise, technologies and materials elaborated in previously EC co-funded projects ATLLAS I & II and LAPCAT I & II. Based on this conceptual design, the consortium has arrived at a key point where they feel comfortable to go to the next step in establishing a detailed design of the vehicle and the preparation of the launch vehicle and flight campaign

Clinical relevance of immersive virtual reality in the assessment and treatment of addictive disorders: A systematic review and future perspective

(1) Background: Virtual reality (VR) has been investigated in a variety of psychiatric disorders, including addictive disorders (ADs); (2) Objective: This systematic review evaluates the current evidence of immersive VR (using head-mounted displays) in the clinical assessment and treatment of ADs; (3) Method: PubMed and PsycINFO were queried for publications up to November 2020; (4) Results: We screened 4519 titles, 114 abstracts and 85 full-texts, and analyzed 36 articles regarding the clinical assessment (i.e., diagnostic and prognostic value; n = 19) and treatment (i.e., interventions; n = 17) of ADs. Though most VR assessment studies (n = 15/19) showed associations between VR-induced cue-reactivity and clinical parameters, only two studies specified diagnostic value. VR treatment studies based on exposure therapy showed no or negative effects. However, other VR interventions like embodied and aversive learning paradigms demonstrated positive findings. The overall study quality was rather poor; (5) Conclusion: Though VR in ADs provides ecologically valid environments to induce cue-reactivity and provide new treatment paradigms, the added clinical value in assessment and therapy remains to be elucidated before VR can be applied in clinical care. Therefore, future work should investigate VR efficacy in randomized clinical trials using well-defined clinical endpoints

Conceptual Design of the High-Speed Propelled Experimental Flight Test Vehicle HEXAFLY

© 2015 AIAA American Institute of Aeronautics and Astronautics. All rights reserved. A concise overview of the overall layout of an experimental powered high-speed flight vehicle including its subsystems is given. A mission scenario, the different flight segments and events to which the payload is exposed are described and justified. This allowed the definition of the aero-thermo-mechanical loads required to conceptually design all elements on board of the vehicle. The final vehicle configuration could achieve the different mission objectives. In particular an aero-propulsive balance, i.e. thrust ≥ drag and lift ≥ weight, could be established at a cruise Mach number of M = 7.4 on the basis of a hydrogen powered scramjet engine while guaranteeing a good aerodynamic efficiency L/D ≥ 4 in a stable, trimmed and controlled way. The experimental combustion campaign could last for at least for 3s up to 9s pending on the finally obtained flight level. This test time is very valuable as it is about 3 orders of magnitude higher of what can be tested in European ground facilities. The vehicle made maximum use of databases, expertise, technologies and materials elaborated in previously EC co-funded projects ATLLAS I & II and LAPCAT I & II. Based on this conceptual design, the consortium has arrived at a key point where they feel comfortable to go to the next step in establishing a detailed design of the vehicle and the preparation of the launch vehicle and flight campaign.status: publishe