Pryor Knowledge Systems, Bloomfield Hills, MI, USA
The waveguide device modeled here specifically demonstrates the exploration of a small, but very important, subset of components of the family of microwave hardware devices designed to facilitate the optimized transfer of power from the generating source to the consuming load. Each of those components is called, in electronics terminology, a Tuned Stub. A stub is a length of transmission line ...
J.E. Rayas-Sánchez, J. Aguilar-Torrentera, Z. Brito-Brito, J.C. Cervantes-González, C.A. López
Universidad Jesuita de Guadalajara, Tlaquepaque, Jalisco, Mexico
Intel Guadalajara Design Center, Tlaquepaque, Jalisco, Mexico
We perform EM simulations of a low-pass microstrip filter consisting of a cross-junction open stub and two unit sections implemented as defected ground structures (DGS). The defect introduced by unit sections corresponds to an etched lattice on the copper backside ground plane. The filter presents wide and deep attenuation characteristics in the stopband. Different model implementations were ...
Analysis of Superheater Tubes with Mutual Irradiation as Applied to a Solar Receiver Steam Generator
N. Lemcoff, S. Wyatt
Rensselaer Polytechnic Institute, Hartford, CT, USA
Alstom Power, Windsor, CT, USA
The objective of this paper is to analyze the temperature variations within a superheater tube of a solar receiver steam generator. The tube is heated by concentrated, collimated solar irradiation with major cooling by an internal steam flow. The influence of heat loss by radiation, internal convection, and conduction are considered. Analytical models are obtained for an isolated tube, and the ...
Design and Nuclear-Safety Related Simulations of Bare-Pellet Test Irradiations for the Production of Pu-238 in the High Flux Isotope Reactor Using COMSOL
J.D. Freels, P.K. Jain, R.W. Hobbs
Oak Ridge National Laboratory, Oak Ridge, TN, USA
The Oak Ridge National Laboratory (ORNL) is developing technology to re-establish the capability to produce plutonium-238 for the National Aeronautics and Space Administration (NASA) as a power source material for powering vehicles while in deep-space. The High Flux Isotope Reactor (HFIR) of ORNL has been utilized to perform test irradiations of in-capsulated neptunium oxide (NpO2) and aluminum ...
N. Elabbasi, X. Liu, S. Brown, M. Vidal, M. Pappalardo
Veryst Engineering LLC, Needham, MA, USA
Nordson EFD, East Providence, RI, USA
Laminar flow static mixers are accurate, inexpensive fluid mixing devices that can handle a wide range of fluids and mixing proportions. They have a wide range of industrial applications, especially in the consumer product, pharmaceutical, biomedical, and petrochemical industries. A good mixing quality is obtained when the outlet of the mixer has no concentrated volumes of either mixed materials ...
Vapor Technologies, Inc., Longmont, CO, USA
The glow discharges in argon at pressures of 1 to 20 mTorr are modeling using COMSOL Plasma Module. DC glow discharge with secondary electron emission is compared to low pressure arc with thermionic emission. Boundary conditions on dielectric discharge tube walls are compared to that of metallic discharge tube walls. Modeling revealed that electron emission mechanisms as well as boundary ...
A Study of the Effects of Mounting Supports, and Dissipation on a Piezoelectric Quartz Double-Ended Tuning Fork Gyroscope
G. Choi, Y. Yong
Rutgers University, New Brunswick, NJ, USA
A COMSOL model of a piezoelectric quartz double ended tuning fork gyroscope was implemented. The gyroscope has two detection modes; the first mode detects the angular velocity about a z-axis perpendicular to the tuning fork plane (x-y plane), while the second mode detects the angular velocity about a y-axis that is the longitudinal axis along the length of the tuning fork. Eigenfrequency ...
L. Graber, N.G. Suttell, D. Shah, D.G. Crook, C.H. Kim, J. Ordonez, S. Pamidi
Center for Advanced Power Systems, Florida State University, Tallahassee, FL, USA
Heat sinks for cryogenic applications using helium gas as the coolant are not readily available. They require to be designed specifically for the intended application. A finite element model was developed to study the feasibility and optimize the design. The FEM computing package COMSOL Multiphysics allowed to couple fluid flow and heat transfer as needed. An experiment was designed to validate ...
University of Hartford, Hartford, CT, USA
Laser percussion drilling is widely used in the aerospace industry to produce cooling holes in jet engine components. This process is a thermal, contact-free process which involves firing a sequence of focused optical pulses onto a target material [1-4]. During each optical pulse, the central portion of the target area heats to a liquid then vapor state where the expanding gas produces a recoil ...
A. Aman, R. Gentile, Y. Chen, X. Huang, Y. Xu, N. Orlovskaya
Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL, USA
Department of Mechanical Engineering, University of South Carolina, Columbia, SC, USA
Solid oxide fuel cells (SOFCs) are electrochemical conversion devices that utilize ceramics as their electrolyte material for oxygen conduction. Compared to other types of fuel cells, they operate at relatively high temperatures, typically 400°C to 1000°C, and have an electrical efficiency over 50% and combined heat and power efficiency over 80%. One way to improve cell performance is to use ...