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Статті в журналах з теми "High-vacuum plume test facility"
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Neumann, Andreas. "STG-ET: DLR Electric Propulsion Test Facility." Journal of large-scale research facilities JLSRF 4 (November 5, 2018): 134. http://dx.doi.org/10.17815/jlsrf-3-156-1.
Повний текст джерелаАнотація:
Abstract: DLR operates the High Vacuum Plume Test Facility Göttingen – Electric Thrusters (STG-ET). This electric propulsion test facility has now accumulated several years of EP-thruster testing experience. Special features tailored to electric space propulsion testing like a large vacuum chamber mounted on a low vibration foundation, a beam dump target made of low sputtering material, and a performant pumping system characterize this facility. The vacuum chamber is 12.2m long and has a diameter of 5m. With respect to accurate thruster testing, the design focus is on accurate thrust measurement, plume diagnostics, and plume interaction with spacecraft components. Electric propulsion thrusters have to run for thousands of hours, and with this the facility is prepared for long-term experiments. This paper gives an overview of the facility, and shows some details of the vacuum chamber, pumping system, diagnostics, and experiences with these components.
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Neumann, Andreas, and Nina Sarah Mühlich. "Ground-Based Experiment for Electric Propulsion Thruster Plume—Magnetic Field Interaction." Aerospace 10, no. 2 (January 26, 2023): 117. http://dx.doi.org/10.3390/aerospace10020117.
Повний текст джерелаАнотація:
Electric space propulsion is a technology which is employed on a continuously increasing number of spacecrafts. While the current focus of their application area is on telecommunication satellites and on space exploration missions, several new ideas are now discussed that go even further and apply the thruster plume particle flow for transferring momentum to targets such as space debris objects or even asteroids. In these potential scenarios, the thruster beam impacts on distant objects and subsequently generates changes in their flight path. One aspect which so far has not been systematically investigated is the interaction of the charged particles in the propulsion beam with magnetic fields which are present in space. This interaction may result in a deflection of the particle flow and consequently affect the aiming strategy. In the present article, basic considerations related to the interaction between electric propulsion thruster plumes and magnetic fields are presented. Experiments with respect to these questions were conducted in the high-vacuum plume test facility for electric thrusters (STG-ET) of the German Aerospace Center in Göttingen utilizing a gridded ion thruster, an RIT10/37, and a Helmholtz coil to generate magnetic fields of varying field strength. It was possible to detect a beam deflection on the RIT ion beam caused by a magnetic field with an Earth-like magnetic field strength.
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Farahani, M., N. Fouladi, and AR Mirbabaei. "Design and analysis of a cooling system for a supersonic exhaust diffuser." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 14 (April 2019): 5253–63. http://dx.doi.org/10.1177/0954410019840970.
Повний текст джерелаАнотація:
High-altitude test facilities are usually used to evaluate the performance of space mission engines. The supersonic exhaust diffuser, a main part of high-altitude test facility, provides the required test cell vacuum conditions by self-pumping the nozzle exhaust gases to the atmosphere. However, the plume temperature is often much higher than the temperature the diffuser structure is able to withstand, usually above 2500 K. In this study, an efficient cooling system is designed and analyzed to resolve the thermal problem. A water spray cooling technique is preferred among various existing techniques. Here, a new algorithm is developed for a spray cooling system for a supersonic exhaust diffuser. This algorithm uses a series of experimental and geometrical relationships to resize the governing parameters and remove the required heat flux from the diffuser surface. The efficiency of the newly designed cooling system is evaluated via numerical simulations. The utilized numerical technique is based on the discrete-phase method. Various computational studies are accomplished to enhance the accuracy of numerical prediction and validation. The present numerical study is validated using experimental results. The results show that the realizable k-ɛ method is superior compared to other Reynolds-averaged Navier–Stokes models.
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Chai, Kil-Byoung, Duck-Hee Kwon, and Minkyu Lee. "Development of plasma beam irradiation facility using applied-field MPD thruster to study plasma-surface interactions." Plasma Physics and Controlled Fusion 63, no. 12 (November 10, 2021): 125020. http://dx.doi.org/10.1088/1361-6587/ac2eb1.
Повний текст джерелаАнотація:
Abstract A plasma beam irradiation facility was developed based on the applied-field magnetoplasmadynamic (AF-MPD) thruster concept for studying plasma-surface interactions. The AF-MPD thruster was chosen because it can produce a plasma beam with high plasma density in continuous-wave mode. Two types of AF-MPD thruster were developed and used in this study: a type I source with a wide thruster channel was used for a heat flux test with Ar or Xe gas, while a type II source with a narrow thruster channel was used for an ion flux test with H2 or He gas. The plasma initially showed the characteristics of abnormal glow discharges and then a transition to arc occurred when the plasma current exceeded a threshold value. It was found that a cathode made of thoriated tungsten significantly lowered the threshold current for the transition from abnormal glow to arc. The maximum heat flux provided by our facility was measured to be 7 MW m−2 using a custom-made heat flux sensor, while the maximum hydrogen ion flux was measured to be 1 × 1023 m−2 s−1 using a Langmuir probe. The electron temperature ranged between (4–5) eV, while the electron density at the plasma plume (downstream) ranged between (1–4) × 1018 m−3.
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Allen, John, and Brian Walsh. "ENHANCED OIL SPILL SURVEILLANCE, DETECTION AND MONITORING THROUGH THE APPLIED TECHNOLOGY OF UNMANNED AIR SYSTEMS." International Oil Spill Conference Proceedings 2008, no. 1 (May 1, 2008): 113–20. http://dx.doi.org/10.7901/2169-3358-2008-1-113.
Повний текст джерелаАнотація:
ABSTRACT Many leading edge technologies that are conceptualized, developed, tested, refined and applied as military defense technologies evolve into useful applied technologies in other public and private sectors. Unmanned Air Systems (UAS) and the rapidly evolving Small Unmanned Air Vehicle (SUAS) are finding operational applications in scientific research, wildlife, law enforcement, security, natural disaster, and environmental surveillance, detection and monitoring. This paper will review the use of UAS in operational oil spill surveillance, monitoring and assessment. UAS show particular potential for shoreline, coastal and inland surveillance and monitoring of remote areas with limited accessibility. Numerous international oil companies have sponsored UAV demonstrations focused on facility and pipeline inspection, surveillance and monitoring. Governmental agencies, including the U.S. Coast Guard and National Oceanic and Atmospheric Agency, have incorporated UAS into oil spill response exercises and test applications. Currently, many areas of high risk to pollution and high environmental sensitivity are monitored daily by costly manned aircraft surveillance; UAS can replace or augment these manned air vehicles, providing a cost effective alternative that also reduces human risks. UAS technology is continually evolving to achieve broader application:On-water launch and in-water recovery;Payload Integration - video, still daylight and nighttime IR imaging, image processing, and hazardous material air plume sensing and mapping;Command, Control and Communications (C-3) - real-time data link to the Incident Command Post;Platform Improvements - greater reliability, minimized size and weight, portability, longer operational flight time and extended range, and improved power sources;GPS positioning - pre-programmed flight patterns and break-away vectoring; andSimulation & Training - train effectively, maintain proficiency, and evolve tactics, techniques and procedures.
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Jelínek, Tomáš, Erik Flídr, Martin Němec, and Jan Šimák. "Test Facility for High-Speed Probe Calibration." EPJ Web of Conferences 213 (2019): 02033. http://dx.doi.org/10.1051/epjconf/201921302033.
Повний текст джерелаАнотація:
A new test facility was built up as a part of a closed-loop transonic wind tunnel in VZLU´s High-speed Aerodynamics Department. The wind tunnel is driven by a twelve stage radial compressor and Mach and Reynolds numbers can be changed by the compressor speed and by the total pressure in the wind tunnel loop by a set of vacuum pumps, respectively. The facility consists of an axisymmetric subsonic nozzle with an exit diameter de = 100 mm. The subsonic nozzle is designed for regimes up to M = 1 at the nozzle outlet. At the nozzle inlet there is a set of a honeycomb and screens to ensure the flow stream laminar at the outlet of the nozzle. The subsonic nozzle can be supplemented with a transonic slotted nozzle or a supersonic rigid nozzle for transonic and supersonic outlet Mach numbers. The probe is fixed in a probe manipulator situated downstream of the nozzle and it ensures a set of two perpendicular angles in a wide range (±90°). The outlet flow field was measured through in several axial distances downstream the subsonic nozzle outlet. The total pressure and static pressure was measured in the centreline and the total pressure distribution in the vertical and horizontal plane was measured as well. Total pressure fluctuations in the nozzle centreline were detected by a FRAP probe. From the initial flow measurement in a wide range of Mach numbers the best location for probe calibration was chosen. The flow field was found to be suitable for probe calibration.
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Swamy Kidambi, Rajamannar, Prakash Mokaria, Samir Khirwadkar, Sunil Belsare, M. S. Khan, Tushar Patel, and Deepu S. Krishnan. "Design and performance of vacuum system for high heat flux test facility." Journal of Physics: Conference Series 823 (April 19, 2017): 012024. http://dx.doi.org/10.1088/1742-6596/823/1/012024.
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Prashana ANL, Kavin, Aldin Justin Sundararaj, and Mukit Azad Khan. "Investigation of nozzle flow in high altitude test facility." Advances in Mechanical Engineering 14, no. 5 (May 2022): 168781402110477. http://dx.doi.org/10.1177/16878140211047724.
Повний текст джерелаАнотація:
A high altitude test facility was developed for the experimental studies on nozzles for various levels of vacuum. The current study is focused on the performance of the nozzle under various altitude condition and to characterized the high altitude test facility. A supersonic nozzle designed for Mach 2.5 is used for the study. Compressed air is taped from the high pressure plenum having a pressure of 20 bar and is regulated and expanded through the nozzle. The inlet pressures for the study is varied from 4.5 to 10 bar. The nozzle is within the enclosure which is evacuated to 0.7–0.02 bar. Schlieren is used to view the flow condition at the end of the nozzle. A nozzle for 2.5 Mach is designed and tested in HAT facility. The nozzle design is validated with the CFD for various NPR. The high altitude test facility is characterized for various NPR and is found to be optimum flow at 14 NPR for 33 s at an inlet pressure of 4.5.
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Lian, Xue, Nan Hua, Liu Jiaqi, Liu Xin, and Meng Gang. "The Design of Large Arc-shape High-precision Walking Device in TV (thermal-vacuum) Conditions." MATEC Web of Conferences 237 (2018): 03014. http://dx.doi.org/10.1051/matecconf/201823703014.
Повний текст джерелаАнотація:
The large-sized space environmental simulation test facility is mainly used for providing thermal radiation environment in high-vacuum, cold and dark space for satellites, spacecraft, lunar spacecraft to carry out whole satellite thermal vacuum test and for large equipment like antenna to carry out tests in TV conditions. Monitoring the spacecraft’s surface optical image or temperature is a main task in space environment simulation test. In previous tests, optical image test mainly took place in a fixed position, so the measuring location and angle are limited. This paper focuses on large spherical space environmental simulation test facility, and designs a large arc-shape high-precision walking device in a space environment simulation test device. It introduces key technology in detail like structure design, thermal design, processes and manufacturing, etc. The test results show that this device can work steadily and reliably under simulation space environments, and the precision exceeds 0.5°.
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Milam, Laura. "Test Facility Requirements for the Thermal Vacuum Thermal Balance Test of the Cosmic Background Explorer Observatory." Journal of the IEST 34, no. 2 (March 1, 1991): 27–33. http://dx.doi.org/10.17764/jiet.2.34.2.b12g343q753w0105.
Повний текст джерелаАнотація:
The cosmic background explorer observatory (COBE) underwent a thermal vacuum/thermal balance (TV/TB) test in the space environment simulator (SES) at the Space Simulation Test Laboratory, Goddard Space Flight Center. This was the largest and most complex test ever accomplished at this facility. The 4 × 4 m (13 × 13 ft) spacecraft weighed approximately 2223 kg (4900 lb) for the test. The test setup included simulator panels for the inboard solar array panels, simulator panels for the, flight cowlings, sun and earth sensor stimuli, thermal/radio frequency shield heater stimuli, and a cryopanel for thermal control in the attitude control system/shunt dissipator area. The fixturing also included a 4.3 m (14 ft) diameter gaseous helium cryopanel which provided a 20° Kelvin (K) (-253° C) environment for the calibration of one of the spacecraft's instruments, the differential microwave radiometer. This cryogenic panel caused extra contamination concerns so a special method was developed and written into the test procedure to prevent the high buildup of condensibles on the panel, which could have led to backstreaming of the thermal vacuum chamber. The test was completed successfully with a high-quality simulated space environment provided to the spacecraft. This paper describes the test requirements, test setup, special fixturing requirements, related contamination concerns, and a general discussion of the test and test results.
Дисертації з теми "High-vacuum plume test facility"
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CONTE, ANTONIETTA. "Advanced Concepts for Rocket Engine Applications." Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2962963.
Повний текст джерелаТези доповідей конференцій з теми "High-vacuum plume test facility"
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Dettleff, Georg, Klaus Plaehn, Georg Dettleff, and Klaus Plaehn. "Initial experimental results from the new DLR-High Vacuum Plume Test Facility STG." In 33rd Joint Propulsion Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1997. http://dx.doi.org/10.2514/6.1997-3297.
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Fulop, Mihaela. "Uncertainty Tool For Large Data Acquisition System." In NCSL International Workshop & Symposium. NCSL International, 2014. http://dx.doi.org/10.51843/wsproceedings.2014.13.
Повний текст джерелаАнотація:
This paper introduces an uncertainty model and analyzer tool being developed for one of the world’s largest space environmental test facilities—the Spacecraft Propulsion Research Facility (B•2) located at NASA Glenn Research Center’s Plum Brook Station near Sandusky, Ohio. The B•2 is the world’s only facility capable of testing full-scale upper-stage launch vehicles and rocket engines under simulated high-altitude conditions (NASA Glenn Research Center, Spacecraft Propulsion Research Facility (B•2), http://facilities.grc.nasa.gov/b2/ Accessed Jan. 22, 2014). Developing an uncertainty tool for the data acquisition of a test facility of this scale presents unique metrology challenges. Not only must the uncertainty analyzer tool be versatile enough to accommodate a wide range of disciplines and measurement requirements (such as temperature, pressure, strain, vacuum, and acceleration), but it must provide a user-interactive platform for evaluating system measurement uncertainty based on customer-chosen measurement scenarios ranging from the most simplistic tests to the most complex ones. The uncertainty analyzer tool, which was developed in Microsoft’s Visual Basic for Applications (VBA) in Excel, will serve multiple purposes, including aiding in the optimal selection of measuring and test equipment, communicating capabilities to customers, and supporting all decisions based on measurements. This paper outlines the methodology followed, the features of this tool, and how the tool can be applied to the measurement processes of different facilities.
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Andreani, Michele, Domenico Paladino, and Tom George. "Simulations of Basic Gas Mixing Tests With Condensation in the PANDA Facility Using the GOTHIC Code." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48917.
Повний текст джерелаАнотація:
In the framework of the OECD SETH project, a number of experiments related to safety issues in the containment of a nuclear reactor have been performed in the large-scale facility PANDA. The tests have been designed to provide an adequate database for basic assessment of CFD and advanced lumped parameter (LP) codes. The test geometry consists of two interconnected vessels (compartments) with fluid injected in one vessel. The gas distribution in the injection vessel and the distribution of gases and the propagation of the stratification in the adjacent vessel are measured. Four of these tests were performed with initial and boundary conditions that resulted in substantial condensation rates. Three of these experiments featured vertical injection (with production of a plume), and in one, the transient response due to a high-momentum horizontal injection (jet) was investigated. The injected fluid was either saturated steam or a superheated mixture of steam and helium, and the fluid initially present in the vessels was pure air. These experiments have been analysed with the advanced containment code GOTHIC, and the main results are presented here. In general, the results obtained with the code and the standard mesh were in good agreement with the data. Limitations in modeling local phenomena controlled by complex flow patterns (e.g. heat transfer in the region of an impinging jet) and the need for refined meshes to reproduce certain aspects of the transients (e.g. erosion of the interface between layers of different gas composition) were also identified.
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Kudlac, Maureen, Harold Weaver, and Mark Cmar. "NASA Plum Brook's B-2 test facility-Thermal vacuum and propellant test facility." In ADVANCES IN CRYOGENIC ENGINEERING: Transactions of the Cryogenic Engineering Conference - CEC, Volume 57. AIP, 2012. http://dx.doi.org/10.1063/1.4707048.
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Ortega, Jesus D., Guillermo Anaya, Peter Vorobieff, Gowtham Mohan, and Clifford K. Ho. "Imaging Particle Temperatures and Curtain Opacities Using an IR Camera." In ASME 2020 14th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/es2020-1688.
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Abstract The Falling Particle Receiver (FPR) at the National Solar Thermal Test Facility (NSTTF) is a testbed for promising receiver technologies offering solutions to the temperature and irradiance limitations exhibited by gas and molten salt receivers, since the particle curtain is directly irradiated without the need of containment. Until recently, the heat loss of the NSTTF 1 MWth FPR was not fully characterized. One of the challenges of the FPR characterization is the intricate flow conditions that the particle curtain experiences due to its cavity design with a single open aperture, to allow the direct irradiance. Recently, particle plumes expelled from the FPR during operation were observed. While this phenomenon affects the FPR heat loss and needs to be closely monitored, it is extremely difficult to operate any kind of sensors near the aperture of the FPR. This work describes the development of a methodology using a high-speed IR camera, located ≥ 5 meters away from the aperture, to estimate the opacity of a particle plume, which in turn can be used to extract the average particle temperature of a region of interest with a known background temperature. Experiments performed at the University of New Mexico using four different flow configurations and three different temperatures (200, 450, and 750°C) were conducted to determine the relationship between the plume opacity in the visible range and the “particle-pixel” opacity obtained from thermograms in the IR range. We present a “particle-pixel function” that describes the combined impact of an unknown number of particles at a specific temperature on a thermogram pixel value with an initial value equal to the background temperature. The novelty of this function is that it provides a reasonable estimate of the plume opacity using thermograms obtained from the IR camera; hence a bulk particle temperature can be obtained. Future development of this methodology will make it possible to compute the advective losses from the FPR and provide a first order approximation of the convective losses for the system.
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Smith, Brendan, Stuart Buckingham, Daniel Touzel, Abigail Corbett, and Charles Tavner. "Development of Methods for Top-Down Methane Emission Measurements of Oil and Gas Facilities in an Offshore Environment Using a Miniature Methane Spectrometer and Long-Endurance UAS." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206181-ms.
Повний текст джерелаАнотація:
Abstract With atmospheric methane concentrations rising, spurring increased social concern, there is a renewed focus in the oil and gas industry on methane emission monitoring and control. In 2019, a methane emission survey at a bp asset west of Shetland was conducted using a closed-cavity methane spectrometer mounted onboard a long-endurance fixed-wing unmanned aerial vehicle (UAV). This flight represents the first methane emissions survey of an offshore facility with a miniature methane spectrometer onboard a UAV with subsequent flights performed. The campaign entailed gathering high-density methane concentration data in a cylindrical flight pattern that circumnavigated the facility in close proximity. A small laser spectrometer was modified from an open-cavity system to a closed-cavity onboard the aircraft and yielded in-flight detection limits (3s) of 1065ppb methane above background for the 2019/2020 sensor version and 150ppb for the 2021 sensor versions. Through simulation, the sensors minimum detection limits in mass flow rate were determined to be 50 kg/h for the 2019/2020 campaign and 2.5kg/h for the 2021 campaigns; translating to an obtainable measurement for 23% and 82% of assets reporting higher than 1 kg/h according to the 2019 EEMS dataset, respectively. To operationalize the approach, a simulation tool for flight planning was developed utilizing a gaussian plume model and a scaled coefficient of variation to invoke expected methane concentration fluctuations at short time intervals. The simulation is additionally used for creation of synthetic datasets to test and validate algorithm development. Two methods were developed to calculate offshore facility level emission rates from the geolocated methane concentration data acquired during the emission surveys. Furthermore, a gaussian plume simulator was developed to predict plume behavior and aid in error analysis. These methods are under evaluation, but all allow for the rapid processing (<24h) of results upon landing the aircraft. Additional flights were conducted in 2020 and 2021 with bp and several UK North Sea Operators through Net Zero Technology Centre (NZTC) funded project, resulting in a total of 18 methane emission survey flights to 11 offshore assets between 2019 and 2021. The 2019 flight, and subsequent 2020/21 flights, demonstrated the potential of the technology to derive facility level emission rates to verify industry emission performance and data.
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Littera, D., M. Velardi, A. Cozzolini, G. Yoder, M. C. Besch, D. K. Carder, and M. Gautam. "Integrated Physical and Chemical Measurements of PM Emissions of Dispersing Plume Heavy-Duty Diesel Truck: Wind Tunnel Studies: Part I — Design and Commissioning." In ASME 2012 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icef2012-92091.
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Over the past few decades there has been considerable progress made in understanding the processes leading to formation and evolution of particulate matter (PM) emissions from heavy duty diesel engines (HDDE). This progress has been primarily made under controlled laboratory conditions with the use of constant volume sampling (CVS) systems and to a limited extend through on-road chase studies. West Virginia University (WVU) is attempting to close the present knowledge gap by conducting detailed experiments in a custom designed and constructed environmental wind tunnel. The understanding and knowledge has recently been further extended to new emission reduction technologies, such as the diesel particulate filter (DPF) which has dramatically changed the size distribution and chemical composition of PM. Additionally, the selective catalytic reduction (SCR) technology has shown to further enhance the formation of nucleation mode particles as well as alter their morphology. Even with advances in technology there remains a considerable gap in the current level of understanding of PM formation and evolution, since the combustion generated PM from diesel engines is not discernible from the atmospheric background PM measured beyond 300m from highways. After being emitted from the vehicle exhaust system, the process of dilution in the atmosphere leads to a multitude of PM transformation phenomena, such as volatilization, coagulation, and condensation. The work presented herein has been divided into two parts which are published separately from each another. The first part describes the design and commissioning process of the wind tunnel focusing on both, aerodynamic and structural constraints, which ultimately led to the definition of the main characteristics of the facility. The resulting design is a subsonic, non-recirculating, suction type tunnel, with a 16ft high and 16ft wide test section capable of housing a full-size heavy-duty tractor cab. A 2,200hp suction fan is employed to provide up to 80 mph wind speeds. The 115ft test cell length guarantees for a 2 second residence time for the exhaust plume evolution (at 35 mph) and complies with turbulence intensity (less than 1%) and quality flow requirement as identified for this type of application. In addition, the West Virginia University (WVU) wind tunnel has been equipped with a custom made sampling system able to move in all three dimensions in order to measure spatially resolved plume characteristics. The second part will describe the actual test procedures and the experimental results and will be published in a separate paper.
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De Lorenzi, A., N. Pilan, A. Pesce, and E. Spada. "Validation progresses of the voltage holding prediction model at the high voltage Padova test facility HVPTF." In 2012 XXVth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV 2012). IEEE, 2012. http://dx.doi.org/10.1109/deiv.2012.6412437.
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Paxton, Brendan, Samir B. Tambe, and San-Mou Jeng. "Systems Design and Experimental Evaluation of a High-Altitude Relight Test Facility." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57089.
Повний текст джерелаАнотація:
Novel advances in gas turbine combustor technology, led by endeavors into fuel efficiency and demanding environmental regulations, have been fraught with performance and safety concerns. While the majority of low emissions gas turbine engine combustor technology has been necessary for power-generation applications, the push for ultra-low NOx combustion in aircraft jet engines has been ever present. Recent state-of-the-art combustor designs notably tackle historic emissions challenges by operating at fuel-lean conditions, which are characterized by an increase in the amount of air flow sent to the primary combustion zone. While beneficial in reducing NOx emissions, the fuel-lean mechanisms that characterize these combustor designs rely heavily upon high-energy and high-velocity air flows to sufficiently mix and atomize fuel droplets, ultimately leading to flame stability concerns during low-power operation. When operating at high-altitude conditions, these issues are further exacerbated by the presence of low ambient air pressures and temperatures, which can lead to engine flame-out situations and hamper engine relight attempts. To aid academic and commercial research ventures into improving the high-altitude lean blow-out (LBO) and relight performance of modern aero turbine combustor technologies, the High-Altitude Relight Test Facility (HARTF) was designed and constructed at the University of Cincinnati Combustion & Fire Research Laboratory (CFRL). This paper presents an overview of its design and an experimental evaluation of its abilities to facilitate optically-accessible combustion and spray testing for aero engine combustor hardware at simulated high-altitude conditions. Extensive testing of its vacuum and cryogenic air-chilling capabilities was performed with regard to end-user control — the creation and the maintenance of a realistic high-altitude simulation — providing a performance limit reference when utilizing the modularity of the facility to implement different aero turbine combustor hardware. Ignition testing was conducted at challenging high-altitude windmilling conditions with a linearly-arranged five fuel-air swirler array to replicate the implementation of a multi-cup gas turbine combustor sector and to evaluate suitable diagnostic tools for the facility. High-speed imaging, for example, was executed during the ignition process to observe flame kernel generation and propagation throughout the primary, or near-field, combustion zones. In the evaluation performed, the HARTF was found to successfully simulate the atmospheric environments of altitudes ranging from sea level to beyond 10,700 m for the employed combustor sector. Diagnostic methods found compatible with the facility include high-speed flame imaging, combustion emission analysis, laser light sheet spray visualization, phase Doppler particle analysis (PDPA), and high-speed particle image velocimetry (HSPIV). Herein discussed are correlations drawn — linking altitude simulation capability to the size of the implemented combustor hardware — and challenges found — vacuum sealing, low pressure fuel injection, fuel vapor autoignition, and frost formation.
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Kapulla, Ralf, Domenico Paladino, Guillaume Mignot, Robert Zboray, and Sanjeev Gupta. "Break-Up of Gas Stratification in LWR Containment Induced by Negatively Buoyant Jets and Plumes." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75708.
Повний текст джерелаАнотація:
For the creation of an experimental database related to physical phenomena relevant for LWR containment safety, tests are performed in MISTRA (CEA, France) and PANDA (PSI, Switzerland) facilities in the frame of the OECD/SETH-2 project. The specific purpose of these tests is to obtain data suitable to improve and validate advanced Lumped Parameter (LP) codes as well as codes with 3D capabilities with respect to the prediction of post-accident containment thermal-hydraulic conditions. The experimental data is related to hydrogen transport within containment compartments. In particular, the effect of mass sources (the release of steam and hydrogen), heat sources (hydrogen-oxygen recombiner), and heat sinks (condensation of steam caused by containment coolers and sprays or “cold” wall) on the break-up/erosion of an initially gas stratified configuration characterized by a layer with a high hydrogen content. Helium is used to simulate hydrogen in the PANDA facility. This paper presents the result of a series of SETH-2 PANDA tests attributed to “vertical fluid release” (plumes or jets). Two large containment compartments (∼180 m3) connected by a bended pipe of ∼1 m diameter are used for these tests. For all the tests, a helium-steam mixture having a thickness of 2 m is created in the upper volume of one compartment while the remaining volume is filled with steam. During the tests, steam jets or plumes are created by injecting steam from a vertical pipe located at the center of the vessel 2 m below the helium-steam mixture. The jet or plume is initially positively buoyant and becomes negatively buoyant once it reaches the helium-steam layer. These transient tests show the degradation of the helium-steam layer for different jet Reynolds numbers. The initial Froude number at the injection pipe varied in the range of ∼3 to ∼9, while the estimated Froude number at the helium-steam mixture/steam interface varied from ∼0.70 to ∼2.