Mechanical Design of Small-Bore Electromagnetic Launchers

1991 ◽  
Vol 113 (1) ◽  
pp. 92-101
Author(s):  
A. K. Thakore ◽  
E. P. Fahrenthold
Keyword(s):  
Mechanical Performance ◽  
Mechanical Design ◽  
Pressure Vessels ◽  
Pulsed Power ◽  
Power Supplies ◽  
Fatigue Reliability ◽  
Electromagnetic Launchers ◽  
Design Changes ◽  
Low Modulus ◽  
Fast Fracture

The development of special-purpose pressure vessels for small-bore, high-velocity electromagnetic launchers has characteristically employed low modulus composites and bolted steel frames. Such designs exhibit low structural stiffness, particularly at high operating currents. Although these designs can be modified to improve mechanical performance, numerical modeling results indicate that basic changes are needed to allow operation at the high bore pressures characteristic of newly developed pulsed power supplies. The indicated design changes introduce a requirement for fast fracture and fatigue reliability analysis of low tensile strength ceramic parts.

Design of Pressure Vessel Cascades for Electromagnetic Launchers

1989 ◽  
Vol 111 (3) ◽  
pp. 326-331
Author(s):  
E. P. Fahrenthold
Keyword(s):  
High Energy ◽  
Pressure Vessels ◽  
Pulsed Power ◽  
Power Supplies ◽  
High Energy Density ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Very High Energy ◽  
Very High

The relatively recent development of very high-energy density pulsed power supplies has motivated a renewed interest in the structural design of electromagnetic launchers. Cascade design electromagnetic launcher pressure vessels offer convenient maintenance access to high wear rate components of the structure while satisfying an unusual combination of electromagnetic, strength, and preloading constraints imposed on the system designer. Analysis for design of such structures focuses on the accurate characterization of fluid-structure interaction under dynamic asymmetric loading.

scholarly journals Stress Analysis for Design of Electromagnetic Launchers

1988 ◽  
Vol 110 (3) ◽  
pp. 395-400 ◽  
Author(s):  
E. P. Fahrenthold ◽  
D. R. Peterson ◽  
J. H. Price ◽  
A. Y. Wu
Keyword(s):  
Structural Analysis ◽  
Stress Analysis ◽  
Pulsed Power ◽  
Power Supplies ◽  
High Current ◽  
Stress Concentrations ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Order Of Magnitude ◽  
Very High

The recent development of very high current pulsed power supplies provides an opportunity for order of magnitude improvements in electromagnetic launcher performance. Consideration of design objectives and constraints suggests that a ceramic-steel construction offers significant advantages over conventional composite-steel railguns. Structural analysis of such a system focuses upon material specific stress concentrations produced by dynamic and asymmetric electromagnetic loads.

Mechanical design of flywheels for energy storage: A review with state-of-the-art developments

2017 ◽  
Vol 233 (5) ◽  
pp. 995-1004 ◽  
Author(s):  
Eugenio Dragoni
Keyword(s):  
Energy Storage ◽  
Large Scale ◽  
Mechanical Performance ◽  
Mechanical Design ◽  
High Strength ◽  
Multilayered Structure ◽  
Pressure Vessels ◽  
Material Strength ◽  
Attractive Alternative ◽  
Simple Relationship

For years, engineers and designers have capitalized on electrochemical batteries for long-term energy storage, which can only last for a finite number of charge–discharge cycles. More recently, compressed hydrogen is being scrutinized as a large-scale storage medium but this poses the risk of spreading high-pressure vessels with inflammable content. Historically, flywheels have provided an effective way to smooth out speed fluctuations in irregular machines and mechanisms. With advancements in composite materials, magnetic bearings, and mechatronic drives, flywheels have become the subject of extensive research as power storage devices for mobile or fixed installations. Flywheel energy storage systems are considered to be an attractive alternative to electrochemical batteries due to higher stored energy density, higher life term, deterministic state of charge and ecological operation. The mechanical performance of a flywheel can be attributed to three factors: material strength, geometry, and rotational speed. Focusing on the simple relationship between these variables, this paper reviews the literature of flywheel technology and explores the merits of four simple but unconventional flywheel configurations that have not been examined so far. Two geometries assume the use of monolithic isotropic materials two solutions are based on the use of high-strength strips or tapes wound up to form a multilayered structure.

Stress Field Around a Large Opening in a Pressure Vessel During a Major Repair

2009 ◽  
Author(s):  
Erik Garrido ◽  
Euro Casanova
Keyword(s):  
Pressure Vessel ◽  
New Technologies ◽  
Mechanical Design ◽  
General Purpose ◽  
Pressure Vessels ◽  
Mechanical Equipment ◽  
Stress Distributions ◽  
Large Opening ◽  
Von Mises ◽  
Case Basis

It is a regular practice in the oil industry to modify mechanical equipment to incorporate new technologies and to optimize production. In the case of pressure vessels, it is occasionally required to cut large openings in their walls in order to have access to the interior part of the equipment for executing modifications. This cutting process produces temporary loads, which were obviously not considered in the original mechanical design. Up to now, there is not a general purpose specification for approaching the assessments of stress levels once a large opening in a vertical pressure vessel has been made. Therefore stress distributions around large openings are analyzed on a case-by-case basis without a reference scheme. This work studies the distribution of the von Mises equivalent stresses around a large opening in FCC Regenerators during internal cyclone replacement, which is a frequently required practice for this kind of equipment. A finite element parametric model was developed in ANSYS, and both numerical results and illustrating figures are presented.

Mechanical Design and Testing of a 2.5 MW sCO2 Compressor Loop

2021 ◽  
Author(s):  
Stefan D. Cich ◽  
J. Jeffrey Moore ◽  
Chris Kulhanek ◽  
Meera Day Towler ◽  
Jason Mortzheim
Keyword(s):  
High Efficiency ◽  
Mechanical Design ◽  
Guide Vane ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Design Changes ◽  
Wide Range ◽  
Inlet Conditions ◽  
Design And Testing

Abstract An enabling technology for a successful deployment of the sCO2 close-loop recompression Brayton cycle is the development of a compressor that can maintain high efficiency for a wide range of inlet conditions due to large variation in properties of CO2 operating near its dome. One solution is to develop an internal actuated variable Inlet Guide Vane (IGV) system that can maintain high efficiency in the main and re-compressor with varying inlet temperature. A compressor for this system has recently been manufactured and tested at various operating conditions to determine its compression efficiency. This compressor was developed with funding from the US DOE Apollo program and industry partners. This paper will focus on the design and testing of the main compressor operating near the CO2 dome. It will look at design challenges that went into some of the decisions for rotor and case construction and how that can affect the mechanical and aerodynamic performance of the compressor. This paper will also go into results from testing at the various operating conditions and how the change in density of CO2 affected rotordynamics and overall performance of the machine. Results will be compared to expected performance and how design changes were implanted to properly counter challenges during testing.

Pulsed power requirements for electromagnetic launchers

1984 ◽  
Vol 20 (2) ◽  
pp. 200-202 ◽  
Author(s):  
W. Weldon ◽  
H. Woodson
Keyword(s):  
Pulsed Power ◽  
Electromagnetic Launchers

Determination and Modeling of the Creep Propagation on High Chromium Steel

2007 ◽  
Author(s):  
Olivier Ancelet ◽  
Ste´phane Chapuliot
Keyword(s):  
Structural Integrity ◽  
Mechanical Design ◽  
Austenitic Stainless Steels ◽  
Numerical Data ◽  
Element Model ◽  
Chromium Steel ◽  
Pressure Vessels ◽  
Experimental Program ◽  
Defect Assessment ◽  
Propagation Law

Modified 9Cr-1Mo steel (T91) is a candidate material for pressure vessels and for some internal structures of GCR (Gas Cooled Reactors). In order to validate this choice, it is necessary, to check if it is covered by the existing design codes, concerning its procurement, fabrication, welding, examination methods and mechanical design rules. A large R&D program on mod 9Cr-1Mo steel has been undertaken at CEA in order to characterize the behavior of this material and of its welded junctions. In this program, the role of the Laboratory for structural Integrity and Standards (LISN) is to develop high temperature defect assessment procedures under fatigue, creep and creep-fatigue loadings, to validate the existing methods (developed on austenitic stainless steels as 316L(N) for the fast reactors) and to get new experimental data on Mod 9Cr-1Mo steel. This paper presents the experimental program undertaken to develop defect assessment under creep loading and describes the main results obtained. Then a creep propagation law is proposed for the Mod 9Cr-1Mo steel at 550°C. To validate the experimental interpretation, a numerical analysis with a 3D finite element model is proposed and allows to model the propagation of the crack. Finally, a comparison of the experimental and the numerical data and in particular of the C* value is investigated.

Structural Integrity and Mechanical Design of a Probe of High Pressure and High Temperature for Oil Wells Applying Finite Elements Tools

2014 ◽  
Author(s):  
Erik Rosado Tamariz ◽  
Rito Mijarez Castro ◽  
Agustín Javier Antúnez Estrada ◽  
Alfonso Campos Amezcua ◽  
David Pascacio Maldonado ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Structural Integrity ◽  
Mechanical Design ◽  
Pressure Vessels ◽  
Oil Wells ◽  
Principal Stresses ◽  
Commercial Code ◽  
And Performance ◽  
Mechanical Elements

Measurement of high pressure and high temperature (HPHT) tools is regularly carried out in the hydrocarbons sector to determine not only the characteristics and performance of fluids inside the well, but also to evaluate the mechanical condition of the pipes and the automation of production. The mechanical features of these tools are significantly influenced by the mechanical design of the structure, which eventually affects their performance and integrity. This paper describes the design process and the analysis of the structural integrity of a HPHT measuring tool for oil wells in its sensors section. The classical theories of mechanical design and specifications of the ASME boilers and pressure vessels code were used. The study is performed for several operation variables in a numerical model using a commercial code of finite element method to determinate the maximum principal stresses, total displacements and safety factor in the mechanical elements that form the device. The numerical results were compared with the experimental data source from the laboratory tests.

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