Introduction to the Molecular Flow Module
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Stall/Surge Dynamics of a Multi-Stage Air Compressor in Response to a Load Transient of a Hybrid Solid Oxide Fuel Cell-Gas Turbine System
Journal of Power Sources 365 (2017) 408e418 Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system * Mohammad Ali Azizi, Jacob Brouwer Advanced Power and Energy Program, University of California, Irvine, USA highlights Dynamic operation of a hybrid solid oxide fuel cell gas turbine system was explored. Computational fluid dynamic simulations of a multi-stage compressor were accomplished. Stall/surge dynamics in response to a pressure perturbation were evaluated. The multi-stage radial compressor was found robust to the pressure dynamics studied. Air flow was maintained positive without entering into severe deep surge conditions. article info abstract Article history: A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and Received 14 August 2017 control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW Accepted 4 September 2017 hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to Keywords: simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW Solid oxide fuel cell system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial Hybrid fuel cell gas turbine Dynamic simulation compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. -
CFD Based Design for Ejector Cooling System Using HFOS (1234Ze(E) and 1234Yf)
energies Article CFD Based Design for Ejector Cooling System Using HFOS (1234ze(E) and 1234yf) Anas F A Elbarghthi 1,*, Saleh Mohamed 2, Van Vu Nguyen 1 and Vaclav Dvorak 1 1 Department of Applied Mechanics, Faculty of Mechanical Engineering, Technical University of Liberec, Studentská 1402/2, 46117 Liberec, Czech Republic; [email protected] (V.V.N.); [email protected] (V.D.) 2 Department of Mechanical and Materials Engineering, Masdar Institute, Khalifa University of Science and Technology, Abu Dhabi, UAE; [email protected] * Correspondence: [email protected] Received: 18 February 2020; Accepted: 14 March 2020; Published: 18 March 2020 Abstract: The field of computational fluid dynamics has been rekindled by recent researchers to unleash this powerful tool to predict the ejector design, as well as to analyse and improve its performance. In this paper, CFD simulation was conducted to model a 2-D axisymmetric supersonic ejector using NIST real gas model integrated in ANSYS Fluent to probe the physical insight and consistent with accurate solutions. HFOs (1234ze(E) and 1234yf) were used as working fluids for their promising alternatives, low global warming potential (GWP), and adhering to EU Council regulations. The impact of different operating conditions, performance maps, and the Pareto frontier performance approach were investigated. The expansion ratio of both refrigerants has been accomplished in linear relationship using their critical compression ratio within 0.30% accuracy. The results show that ± R1234yf achieved reasonably better overall performance than R1234ze(E). Generally, by increasing the primary flow inlet saturation temperature and pressure, the entrainment ratio will be lower, and this allows for a higher critical operating back pressure. -
MSME with Depth in Fluid Mechanics
MSME with depth in Fluid Mechanics The primary areas of fluid mechanics research at Michigan State University's Mechanical Engineering program are in developing computational methods for the prediction of complex flows, in devising experimental methods of measurement, and in applying them to improve understanding of fluid-flow phenomena. Theoretical fluid dynamics courses provide a foundation for this research as well as for related studies in areas such as combustion, heat transfer, thermal power engineering, materials processing, bioengineering and in aspects of manufacturing engineering. MS Track for Fluid Mechanics The MSME degree program for fluid mechanics is based around two graduate-level foundation courses offered through the Department of Mechanical Engineering (ME). These courses are ME 830 Fluid Mechanics I Fall ME 840 Computational Fluid Mechanics and Heat Transfer Spring The ME 830 course is the basic graduate level course in the continuum theory of fluid mechanics that all students should take. In the ME 840 course, the theoretical understanding gained in ME 830 is supplemented with material on numerical methods, discretization of equations, and stability constraints appropriate for developing and using computational methods of solution to fluid mechanics and convective heat transfer problems. Students augment these courses with additional courses in fluid mechanics and satisfy breadth requirements by selecting courses in the areas of Thermal Sciences, Mechanical and Dynamical Systems, and Solid and Structural Mechanics. Graduate Course and Research Topics (Profs. Benard, Brereton, Jaberi, Koochesfahani, Naguib) ExperimentalResearch Many fluid flow phenomena are too complicated to be understood fully or predicted accurately by either theory or computational methods. Sometimes the boundary conditions of real-world problems cannot be analyzed accurately. -
Flex-Line & Rondeo
Flex-Line User manual Flex-Line & Rondeo OPERATING MANUAL 1 Flex-Line User manual 2 Flex-Line User manual 1. Table of contents 1. Table of contents ............................................................................................................................3 2. Editorial ..........................................................................................................................................5 2.1. Purpose of the manual ...........................................................................................................6 2.2. Keeping the manual ...............................................................................................................6 2.3. Other applicable documents ..................................................................................................6 2.4. Safety information ..................................................................................................................6 3. Information about the product .........................................................................................................8 3.1. Type test ................................................................................................................................8 3.2. Requirements for installation and operation ...........................................................................8 3.3. Intended use ..........................................................................................................................8 3.4. Temporary-burning fireplace ..................................................................................................8 -
Traghella 1 Kaydee Traghella Mclaughlin WRTG 100-10 30 April
Traghella 1 Kaydee Traghella McLaughlin WRTG 100-10 30 April 2013 Green Design: Good for the Planet, Good for One’s Health Reduce, reuse, and recycle. This is a common phrase people hear when it comes to the “going green” movement. However, some people are unsure how to actually incorporate this phrase into their life and see an effect. A great starting point is the home, since it is a place where a majority of people's time is spent. The construction industry focuses on cheap and quick design. It does not take into account where the materials came from, the pollution that is created from the building process, or what happens to the products used at the end of their lives (Choosing Sustainable Materials). Green homes use less resources, energy, and water than conventional homes that were once built (Dennis 93). Many people think about the effects on our planet from building a home, but few think of the harmful health effects new homes can have on one’s body. Although a green home will benefit the planet, a green home can also have health benefits for the occupants living inside it. Lori Dennis, an interior designer and environmentalist, states in her book Green Interior Design, “Green is a term used to describe products or practices that have little or no harmful effects to the environment or human health”(6). The old and traditional ways that homes were built and the way they are still operated now contribute to smog, acid rain, and global warming because those types of homes are still in use (93). -
Low Outgassing Materials
LOW OUTGASSING MATERIALS Low Outgassing Materials GENERAL DESCRIPTION In many critical aerospace and semiconductor applications, low-outgassing materials must be specified in order to prevent contamination in high vacuum environments. Outgassing occurs when a material is placed into a vacuum (very low atmospheric pressure) environment, subjected to heat, and some of the material’s constituents are volatilized (evaporated or “outgassed”). ASTM TEST METHOD E595 Although other agency-specific tests do exist (NASA, ESA, ESTEC), outgassing data for comparison is generally obtained in accordance with ASTM Test Method E595-93, “Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in a Vacuum Environment”. In Test Method E595, the material sample is heated to 125°C for 24 hours while in a vacuum (typically less than 5 x 10-5 torr or 7 x 10-3 Pascal). Specimen mass is measure before and after the test and the difference is expressed as percent total mass loss (TML%). A small cooled plate (at 25°C) is placed in close proximity to the specimen to collect the volatiles by condensation ... this plate is used to determine the percent collected volatile condensable materials (CVCM%). An additional parameter, Water Vapor Regained (WVR%) can also be determined after completion of exposures and measurements for TML and CVCM. ASTM Test Method E595 data is most often used as a screening test for spacecraft materials. Actual surface contamination from the outgassing of materials will, of course, vary with environment and quantity of material used. The criteria of TML < 1.0% and CVCM < 0.1% has been typically used to screen materials from an outgassing standpoint in spaceflight applications. -
COMSOL Computational Fluid Dynamics for Microreactors Used in Volatile Organic Compounds Catalytic Elimination
COMSOL Computational Fluid Dynamics for Microreactors Used in Volatile Organic Compounds Catalytic Elimination Maria Olea 1, S. Odiba1, S. Hodgson1, A. Adgar1 1School of Science and Engineering, Teesside University, Middlesbrough, United Kingdom Abstract Volatile organic compounds (VOCs) are organic chemicals that will evaporate easily into the air at room temperature and contribute majorly to the formation of photochemical ozone. They are emitted as gases from certain solids and liquids in to the atmosphere and affect indoor and outdoor air quality. They includes acetone, benzene, ethylene glycol, formaldehyde, methylene chloride, perchloroethylene, toluene, xylene, 1,3-butadiene, butane, pentane, propane, ethanol, etc. Source of VOCs emission include paints, industrial processes, transportation activities, household products such as cleaning agents, aerosols, fuel and cosmetics. Catalytic oxidation is one of the most promising elimination techniques for VOCs as a result of it flexibility and energy saving. The catalytic materials enhance the chemical reactions that convert VOCs (through oxidation) into carbon dioxide and water. Removal of volatile organic compounds at room temperature has always been a challenge to researchers. Developing a catalyst which could completely oxidize the VOCs at very low temperature in order to avoid catalyst deactivation and promote energy saving has been the key focus among researchers in the recent years. Moreover, as the oxidation reaction is highly exothermic, the use of catalytic microreactors instead of packed bed reactors was considered. Microreactors are microfabricated catalytic chemical reactors with at least one linear dimension in the micrometer range. Usually, they consist of narrow channels and exhibit large surface area-to- volume ratios which leads to high heat and mass transfer properties. -
Dependence of Tritium Release on Temperature and Water Vapor from Stainless Steel
DEPENDENCE OF TRITIUM RELEASE ON TEMPERATURE AND WATER VAPOR FROM STAINLESS STEEL Dependence of Tritium Release on Temperature and Water Vapor from Stainless Steel Introduction were exposed to 690 Torr of DT gas, 40% T/D ratio, for 23 h at Tritium has applications in the pharmaceutical industry as a room temperature and stored under vacuum at room tempera- radioactive tracer, in the radioluminescent industry as a scintil- ture until retrieved for the desorption studies, after which they lant driver, and in nuclear fusion as a fuel. When metal surfaces were stored under helium. The experiments were conducted are exposed to tritium gas, compounds absorbed on the metal 440 days after exposure. The samples were exposed briefly to surfaces (such as water and volatile organic species) chemically air during the transfer from storage to the desorption facility. react with the tritons. Subsequently, the contaminated surfaces desorb tritiated water and volatile organics. Contact with these The desorption facility, described in detail in Ref. 6, com- surfaces can pose a health hazard to workers. Additionally, prises a 100-cm3, heated quartz tube that holds the sample, a desorption of tritiated species from the surfaces constitutes a set of two gas spargers to extract water-soluble gases from the respirable dose. helium purge stream, and an on-line liquid scintillation counter to measure the activity collected in the spargers in real time. Understanding the mechanisms associated with hydrogen The performance of the spargers has been discussed in detail adsorption on metal surfaces and its subsequent transport into in Ref. 7. Tritium that desorbs from metal surfaces is predomi- the bulk can reduce the susceptibility of surfaces becoming nantly found in water-soluble species.7 contaminated and can lead to improved decontamination tech- niques. -
CKM Vacuum Veto System Vacuum Pumping System
CKM Vacuum Veto System Vacuum Pumping System Technical Memorandum CKM-80 Del Allspach PPD/Mechanical/Process Systems March 2003 Fermilab Batavia, IL, USA TABLE OF CONTENTS 1.0 Introduction 3 2.0 VVS Outgassing Distribution 3 3.0 VVS High Vacuum Pumping System Solutions 4 3.1 Diffusion Pump System for the VVS 3.2 Turbo Molecular Pump System for the VVS 3.3 Turbo Molecular Pump System for the DMS Region 3.4 VVS Cryogenic Vacuum Pumping System 4.0 Roughing System 6 5.0 Summary 6 6.0 References 7 p. 2 1.0 Introduction This technical memorandum discusses two solutions for achieving the pressure specification of 1.0E-6 Torr for the CKM Vacuum Veto System (VVS). The first solution includes the use of Diffusion Pumps (DP’s) for the volume upstream of the Downstream Magnetic Spectrometer (DMS) regions. The second solution uses Turbo Molecular Pumps (TMP’s) for the upstream volume. In each solution, TMP’s are used for each of the four DMS regions. Cryogenic Vacuum Pumping is also considered to supplement the upstream portion of the VVS. The capacity of the Roughing System is reviewed as well. The distribution of the system outgassing is first examined. 2.0 VVS Outgassing Distribution There are several sources of outgassing in the VVS vacuum vessel. These sources are discussed in a previous note [1]. The distribution of the outgassing within the VVS is now considered. The VVS detector total outgassing rate was determined to be 1.0E-2 Torr-L/sec. The upstream portion accounts for 54% of this rate while the downstream side is 46% of the rate. -
Ultra Low Outgassing Lubricants
ULTRA LOW OUTGASSING LUBRICANTS Next-Generation Lubricants for Cleanroom and Vacuum Applications - Ultra Low Outgassing, Vacuum Stability, Low Particle Generation Nye Lubricants for Cleanroom and Vacuum The Right Lubricant for the Right Application - Applications NyeTorr® 6200 and NyeTorr® 6300 Today’s vast array of electromechanical devices in Nye Lubricants offers NyeTorr® 6200 and NyeTorr® semiconductor wafer fabrication, flat panel, solar panel 6300, designed to improve the performance and and LCD manufacturing equipment place increasingly extend the operating life of high-speed bearings, challenging demands on their lubricants. Lubricants linear guides for motion control, vacuum pumps, and today must be able to handle higher loads, higher other components used in semicon manufacturing temperatures, extend component operating life, and equipment designed for processes such as deposition, improve productivity, while eliminating or minimizing ion implantation, etching, photolithography, and wafer airborne molecular contamination or giving off vapors measurement and inspection. that can fog optics in high-speed inspection systems or even contaminate wafers. Nye tests and certifies the vacuum stability (E-595) of each batch. Other vacuum lubricants list only “typical For more than 50 years, Nye has been working with properties,” which do not warrant that vapor pressure NASA and leaders in the commercial aerospace on the label matches the actual vapor pressure of the industry, qualifying lubricants for mission critical lubricant. And most often, it doesn’t. components while addressing problems like outgassing, contamination, and starvation. Outgassing Additionally, all NyeTorr cleanroom lubricants are reduces the effectiveness of a lubricant and can subjected to a proprietary “ultrafiltration process” contaminate nearby components. which removes microscopic particulates and homogenizes agglomerated thickeners. -
THERMODYNAMICS, HEAT TRANSFER, and FLUID FLOW, Module 3 Fluid Flow Blank Fluid Flow TABLE of CONTENTS
Department of Energy Fundamentals Handbook THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW, Module 3 Fluid Flow blank Fluid Flow TABLE OF CONTENTS TABLE OF CONTENTS LIST OF FIGURES .................................................. iv LIST OF TABLES ................................................... v REFERENCES ..................................................... vi OBJECTIVES ..................................................... vii CONTINUITY EQUATION ............................................ 1 Introduction .................................................. 1 Properties of Fluids ............................................. 2 Buoyancy .................................................... 2 Compressibility ................................................ 3 Relationship Between Depth and Pressure ............................. 3 Pascal’s Law .................................................. 7 Control Volume ............................................... 8 Volumetric Flow Rate ........................................... 9 Mass Flow Rate ............................................... 9 Conservation of Mass ........................................... 10 Steady-State Flow ............................................. 10 Continuity Equation ............................................ 11 Summary ................................................... 16 LAMINAR AND TURBULENT FLOW ................................... 17 Flow Regimes ................................................ 17 Laminar Flow ............................................... -
An Electron Beam Heated Evaporation Source
An Electron Beam Heated Evaporation Source Martin Magnuson Department of Physics, Uppsala University, Box 530, S-75121 Uppsala, Sweden 1994 Abstract An electron beam evaporator has been assembled, tested and used for deposition of thin nickel films. Flux and deposition rates has been measured with an oscillating quartz crystal monitor (QCM), an ion sensor wire, and visible deposition on a mirror on front of the evaporator. A thin nickel rod of 2 mm diameter was found to improve the pressure in comparison to a 6-mm nickel rod. The flux was typically 3-4 Angstroms per minute during the test, but other flux rates can easily be achieved by changing the filament current and the acceleration voltage. 1. Introduction Electron beam heating is an efficient way of achieving high temperatures when tungsten filament evaporators are not suitable, e.g., when the tungsten filament alloys with the evaporator material. A beam of electrons is produced by a hot tungsten filament. The beam of electrons is accelerated and electrostatically focused to a tip of a metal rod (nickel) held at a high positive potential. The electron beam-creates high temperatures in the source material so that almost any material can be evaporated (melting point of nickel=1453 degrees Celsius). Since the rate of evaporation for materials increases with greater power input, the highest rates are obtained with materials that have low evaporation temperatures and low thermal conductivity. The magnitude of the pressure, which increases during evaporation, depends on the pumping capacity of the system and the cleanliness of the evaporated material. The outgassing of the surrounding surfaces was minimized by water cooling of the surrounding walls.