scholarly journals Bus Impact on the Inductance Distribution of Electromagnetic Launchers

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Simulation Models ◽  
Careful Examination ◽  
Physical Conditions ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Bus Structure ◽  
Electromagnetic Calculations ◽  
Operation Risk ◽  
Current Transients ◽  
Good Agreement

<div>Simulations are crucial in the electromagnetic launcher (EML) researches on account of extreme physical conditions. More energy into the system adds weight to the model’s accuracy as the operation risk rises. In this paper, the electromagnetic impact of the bus structure is discovered in a recently developed EMFY-3 electromagnetic launcher, is presented. An H-shaped bus structure is used for current injection. However, experiments showed that the H-shaped bus changes inductance calculations. A careful examination is made to reveal the physical reasoning of the bus impact. We hypothesize that the rail portion surrounded with bus geometry has less inductance than the rest due to the eddy current created by rail current transients, which should be calculated carefully through numerical calculations, i.e., 3-D Finite Element Method (FEM). Two different simulation models were constructed to test the hypothesis. Moreover, rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Results showed a good agreement with experiments where the bus structure was modeled explicitly. That aspect showed that the bus structure should be well-examined when multiple PPS are connected.</div>

scholarly journals Bus Impact on the Inductance Distribution of Electromagnetic Launchers

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Simulation Models ◽  
Careful Examination ◽  
Physical Conditions ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Bus Structure ◽  
Electromagnetic Calculations ◽  
Operation Risk ◽  
Current Transients ◽  
Good Agreement

<div>Simulations are crucial in the electromagnetic launcher (EML) researches on account of extreme physical conditions. More energy into the system adds weight to the model’s accuracy as the operation risk rises. In this paper, the electromagnetic impact of the bus structure is discovered in a recently developed EMFY-3 electromagnetic launcher, is presented. An H-shaped bus structure is used for current injection. However, experiments showed that the H-shaped bus changes inductance calculations. A careful examination is made to reveal the physical reasoning of the bus impact. We hypothesize that the rail portion surrounded with bus geometry has less inductance than the rest due to the eddy current created by rail current transients, which should be calculated carefully through numerical calculations, i.e., 3-D Finite Element Method (FEM). Two different simulation models were constructed to test the hypothesis. Moreover, rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Results showed a good agreement with experiments where the bus structure was modeled explicitly. That aspect showed that the bus structure should be well-examined when multiple PPS are connected.</div>

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.

Comparison and Validation of Dynamics Simulation Models for a Structurally Flexible Manipulator

1998 ◽  
Vol 120 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Jeff Stanway ◽  
Inna Sharf ◽  
Chris Damaren
Keyword(s):  
Simulation Models ◽  
Element Model ◽  
Experimental Results ◽  
Dynamics Simulation ◽  
Flexible Manipulator ◽  
Direct Drive ◽  
Inertial Nonlinearities ◽  
Dynamics Models ◽  
The Finite Element Model ◽  
Good Agreement

This paper presents a series of experimental results obtained with a 2-DOF flexible-link direct-drive manipulator. First, we conduct a frequency analysis by comparing experimental natural frequencies with those predicted by the finite element model. Then, the time responses from four dynamics models are compared with each other and with the experiment. It is demonstrated that higher order nonlinearities are less important for slow maneuvers by close agreement between all four simulation models. For fast maneuvers, the two simpler models fail to predict a physically meaningful response. Good agreement with experimental results is attained with a model which accounts for all inertial nonlinearities. It is also shown that inclusion of damping in the dynamics models has a significant impact on their performance, as well as improving the correlation with experimental data.

Neutron Diffraction Residual Stress Evaluation and Numerical Modeling of Coating Obtained by PTA Process

2010 ◽  
Vol 638-642 ◽  
pp. 594-599
Author(s):  
Abdeljalil Nady ◽  
Herve Bonnefoy ◽  
Vincent Klosek ◽  
Marie Helene Mathon ◽  
Alain Lodini
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses ◽  
Complex Geometry ◽  
Steel Substrate ◽  
Diffraction Method ◽  
Stress Evaluation ◽  
Physical Conditions ◽  
Abaqus Code ◽  
Neutron Diffraction Method ◽  
Good Agreement

The Stellite 6 hardfacing alloys have been deposited on steel substrate using a Plasma Transferred Arc (PTA) with complex geometry. The residual strain of the PTA technology at the surface of coating layer and the interface were determined by neutron diffraction method. In the present work, a numerical model for the residual stresses formed during the PTA process with physical conditions and mechanical properties using the Abaqus code is analysed. The result reveals that the residual stresses obtained by the numerical simulation are in very good agreement with experimental results by the neutron diffraction.

scholarly journals Computations of Magnetic Forces in Multipole Field Electromagnetic Launcher

2019 ◽  
Vol 4 (3) ◽  
pp. 761-774 ◽  
Author(s):  
Srichandan Kondamudi ◽  
Mallikarjuna Rao Pasumarthi
Keyword(s):  
Finite Element Analysis ◽  
Flux Distribution ◽  
Element Analysis ◽  
Flux Lines ◽  
Magnetic Forces ◽  
Electromagnetic Launchers ◽  
Lorentz Equation ◽  
Electromagnetic Launcher ◽  
Multipole Field ◽  
Force Characteristics

Multipole Field Electromagnetic Launchers (MFEML) is one of the radial electromagnetic launching mechanisms, which can propel a payload for long distances. This paper proposes formulae for inductance based on the magnetic flux distribution in the coils of MFEML. Flux lines flow is sectionalized, for each section reluctance formulae is derived based on the position of the projectile. Based on the principles of the Lorentz equation, magnetic forces are calculated. This paper presents an electrical and magnetic equivalent circuit of MFEML. The velocity and force characteristics are obtained for the proposed formulae. The results are validated using Finite element analysis.

Validations of Particle/Fluid Interaction Models

2004 ◽  
Author(s):  
Z. Charlie Zheng ◽  
N. Zhang ◽  
S. Eckels
Keyword(s):  
Turbulence Model ◽  
Gravitational Force ◽  
Simulation Models ◽  
Fluid Simulation ◽  
Particle Collision ◽  
Type Model ◽  
Interaction Models ◽  
Fluid Interaction ◽  
Good Agreement

Several particle/fluid simulation models have been tested, including Euler-Lagrange type and Euler type models. Other effects, such as gravitational force, turbulence model and particle collision, are also discussed. Comparisons with literature data have shown good agreement by using the Euler type model.

Recommendations for singlet-based approach in ligand binding assays: an IQ Consortium perspective

Bioanalysis ◽  
2020 ◽  
Author(s):  
Renuka Pillutla ◽  
Boris Gorovits ◽  
Carol Gleason ◽  
Jorge Quiroz ◽  
David Christopher ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Simulation Models ◽  
Study Quality ◽  
Binding Assays ◽  
Pharmaceutical Development ◽  
Drug Candidates ◽  
Leadership Group ◽  
The Impact ◽  
Analytical Platforms ◽  
Good Agreement

Historically, ligand-binding assays for pharmacokinetic samples employed duplicate rather than singlet-based analysis. Herein, the Translational and absorption, distribution, metabolism and excretion (ADME) Sciences Leadership Group of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) presents a study aiming to determine the value of duplicate versus singlet-based testing. Based on analysis of data collected from eight organizations for 20 drug candidates representing seven molecular types and four analytical platforms, statistical comparisons of validation and in-study quality controls and study unknown samples demonstrated good agreement across duplicate sets. Simulation models were also used to assess the impact of sample duplicate characteristics on bioequivalence outcomes. Results show that testing in singlet is acceptable for assays with % CV ≤15% between duplicates. Singlet-based approach is proposed as the default for ligand-binding assays while a duplicate-based approach is needed where imprecision and/or inaccuracy impede the validation of the assay.

Radiation Effects on 1.7kV Class 4H-SiC Power Devices: Development of Compact Simulation Models

2019 ◽  
Vol 963 ◽  
pp. 718-721
Author(s):  
Pavel Hazdra ◽  
Stanislav Popelka
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Radiation Effects ◽  
Deep Level ◽  
Dose Range ◽  
Simulation Models ◽  
Electrical Characteristics ◽  
Power Devices ◽  
Power Mosfets ◽  
Transient Spectroscopy ◽  
Good Agreement

Compact simulation models of two key silicon carbide power components, the Junction Barrier Schottky diode and the power MOSFET, which are taking into account the effect of irradiation by highenergy electrons, were developed. Two 1.7 kV class devices: the 14 A JBS diode C3D10170H and the 5 A SiC power MOSFETs C2M1000170D produced by Wolfspeed were irradiated by 4.5 MeV electrons in the dose range up to 2000 kGy. Electrical characteristics were measured prior to and after irradiation. Radiation defects were studied by deep level transient spectroscopy and the effect of irradiation on device characteristics was established. SPICE models taking into account the irradiation fluence were proposed and calibrated using the parameters extracted from experiment. Simulated characteristics show a very good agreement with reality.

scholarly journals Materials Selection in Electromagnetic Launcher Design

1989 ◽  
Vol 111 (3) ◽  
pp. 319-326 ◽  
Author(s):  
E. P. Fahrenthold
Keyword(s):  
Numerical Modeling ◽  
Composite Structure ◽  
Electrical Performance ◽  
Next Generation ◽  
Materials Selection ◽  
Electromagnetic Launchers ◽  
Electromagnetic Simulations ◽  
Laboratory Facilities ◽  
Electromagnetic Launcher ◽  
Alternative Designs

The design of electromagnetic launchers includes a large materials selection component, with the use of available structural materials constrained by electrical performance considerations. Feasible material combinations for the composite structure are limited, with mechanical and thermo-electromagnetic simulations required to compare the performance of alternative designs. Numerical modeling studies suggest that next generation devices constructed for laboratory facilities or vehicular mounting may differ markedly in material composition, yet offer similar and significant structural improvements over conventional railgun designs.

scholarly journals Numerical modelling of heat transfers between inductively heated metallic and dielectric phases

2020 ◽  
Vol 39 (1) ◽  
pp. 108-116
Author(s):  
Rémi Bourrou ◽  
Olga Budenkova ◽  
Christophe Lafon ◽  
Annie Gagnoud
Keyword(s):  
Radiative Heat ◽  
Low Frequency ◽  
Metallic Phase ◽  
Radiative Heat Exchange ◽  
Content Type ◽  
Vof Model ◽  
Electromagnetic Calculations ◽  
Heat Transfers ◽  
Varying Viscosity ◽  
Good Agreement

Purpose Heating with a low-frequency induction is a key phenomenon in a process dedicated to the treatment of nuclear wastes. This paper aims to present a step of the numerical model being developed to study this process. Design/methodology/approach A hydrodynamic model for the processing of a liquid charge consisting of a metallic phase and a dielectric one is developed based on a volume of fluid (VOF) approach coupled with electromagnetic calculations. The latter allows one to calculate the distribution of the Joule heating in the setup and radiative heat exchange inside the crucible is accounted with a surface-to-surface (S2S) model coupled with VOF. Findings Numerical results are compared with the measures obtained on the prototype of the process. The results are in good agreement but the model needs to be improved to consider the varying viscosity of the glass. Originality/value The usage of a S2S radiation model coupled to the VOF model is not common for studies of materials melted by electromagnetic induction. This paper demonstrates the feasibility of this approach.

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