Open Applicator Analysis For Material Joining And Dielectric Measurements

1996 ◽  
Vol 430 ◽  
Author(s):  
S. P. Chen ◽  
W. R. Tinga ◽  
F. E. Vermeulen
Keyword(s):  
Steady State ◽  
Dielectric Properties ◽  
Elevated Temperatures ◽  
Field Measurements ◽  
Steady State Solution ◽  
Dielectric Measurements ◽  
External Electromagnetic Fields ◽  
Quarter Wave ◽  
Planar Materials ◽  
Good Agreement

AbstractResonant internal and radiated external electromagnetic fields of an open coaxial structure are analyzed using FDTD. These fields are characterized for two structures, with and without a quarter-wave choke. Techniques utilized to obtain a steady state solution are discussed. Good agreement with field measurements is obtained. This moveable open applicator is convenient for creating intense hot zones as required in ceramic joining. It is also suitable for the measurement of surface dielectric properties of planar materials at room or elevated temperatures.

Stratified flow over a bounded obstacle in a channel of finite height

1981 ◽  
Vol 110 ◽  
pp. 161-170 ◽  
Author(s):  
G. S. Janowitz
Keyword(s):  
Steady State ◽  
Stratified Flow ◽  
Steady State Solution ◽  
The Body ◽  
State Solution ◽  
Oseen Equations ◽  
Finite Height ◽  
Experimental Values ◽  
Oseen Model ◽  
Good Agreement

The steady-state solution for the stratified flow over a bounded obstacle in a channel of finite height is obtained through the use of the inviscid unsteady Oseen equations; the body streamline encloses and is produced by a planar momentum sink. The calculations are compared with the experimental observations of Wei, Kao & Pao (1975) and Baines (1977). In a case where theoretical and experimental values match, good agreement was found. This suggests that the Oseen model with its columnar, wavelike and decaying solutions may provide a reasonable alternative to Long's model for subcritical flows.

Modification and Dielectric Properties of Polyisoprene

1983 ◽  
Vol 56 (4) ◽  
pp. 718-725
Author(s):  
J. Honskus
Keyword(s):  
Dielectric Properties ◽  
Chemical Analyses ◽  
Dielectric Measurements ◽  
Dielectric Method ◽  
Polar Groups ◽  
Good Agreement

Abstract The dielectric method can be used for determination of the polar groups modifying the nonpolar polymers. This method was used for the study of such complicated systems as the sulfur-accelerated vulcanizates. Results of the chemical analyses were compared with the results of dielectric measurements, and very good agreement was obtained.

Coronas and the space charge problem

1991 ◽  
Vol 2 (1) ◽  
pp. 43-81 ◽  
Author(s):  
Chris Budd
Keyword(s):  
Steady State ◽  
Asymptotic Analysis ◽  
Space Charge ◽  
Large Time ◽  
Steady State Solution ◽  
Travelling Wave ◽  
Macroscopic Motion ◽  
The Relationship ◽  
Charged Ions ◽  
Good Agreement

This paper presents a detailed analysis of a model for a positive corona discharge, and discusses the relationship between the model and the space charge equations which predict the macroscopic motion of charged ions in a gas. The study is restricted to the asymptotic behaviour of the discharge for large time, and it does not consider its initial or burst phases in detail.One prediction of this model is the existence of a steady state solution to the space charge equations that may lose stability to a travelling wave disturbance which then grows into a strongly pulsed oscillation.We compare some numerical calculations with an asymptotic analysis of the discharge and find good agreement.

High Temperature Dielectric Measurements on Ceramics

1992 ◽  
Vol 269 ◽  
Author(s):  
M Aral ◽  
J G P Binner ◽  
G E Carr ◽  
T E Cross
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Alternative Energy ◽  
Elevated Temperatures ◽  
Microwave Dielectric Properties ◽  
Microwave Frequency ◽  
Dielectric Measurements ◽  
Microwave Dielectric ◽  
The University ◽  
Processing Group

ABSTRACTThe use of microwave frequency radiation as an alternative energy source for processing materials is currently receiving considerable worldwide attention. The ability of a material to extract energy from the microwave field depends upon its dielectric properties, however these change as the material heats. There is, therefore, a need for obtaining measurements of the microwave dielectric properties at elevated temperatures. This paper outlines some of the current work on high temperature dielectric measurements which is in progress at the University of Nottingham as part of the Materials and Microwave Processing Group initiative and some results on engineering ceramics are presented.

Diffusion of gases in liquids: the constant size bubble method

1969 ◽  
Vol 47 (6) ◽  
pp. 1075-1077 ◽  
Author(s):  
Wing Y. Ng ◽  
John Walkley
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Steady State ◽  
Diffusion Equation ◽  
Diffusion Coefficients ◽  
Steady State Solution ◽  
State Solution ◽  
Constant Size ◽  
Good Agreement ◽  
Diffusion Of Gases

A method is described by which the diffusion of a gas in a liquid is measured by maintaining a bubble of the gas at constant size in the liquid. A steady state solution to the diffusion equation is seen to fit the observed experimental data. The measured diffusion coefficients for nitrogen, oxygen, and carbon dioxide in water at 25 °C are found in good agreement with previously determined values.

An airfoil theory of bifurcating laminar separation from thin obstacles

1990 ◽  
Vol 216 ◽  
pp. 255-284 ◽  
Author(s):  
C. J. Lee ◽  
H. K. Cheng
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Steady State ◽  
Steady State Solution ◽  
Equation System ◽  
Branch Points ◽  
Laminar Separation ◽  
Kutta Condition ◽  
Numerical Studies ◽  
Steady State Solutions

Global interaction of the boundary layer separating from an obstacle with resulting open/closed wakes is studied for a thin airfoil in a steady flow. Replacing the Kutta condition of the classical theory is the breakaway criterion of the laminar triple-deck interaction (Sychev 1972; Smith 1977), which, together with the assumption of a uniform wake/eddy pressure, leads to a nonlinear equation system for the breakaway location and wake shape. The solutions depend on a Reynolds numberReand an airfoil thickness ratio or incidence τ and, in the domain$Re^{\frac{1}{16}}\tau = O(1)$considered, the separation locations are found to be far removed from the classical Brillouin–Villat point for the breakaway from a smooth shape. Bifurcations of the steady-state solution are found among examples of symmetrical and asymmetrical flows, allowing open and closed wakes, as well as symmetry breaking in an otherwise symmetrical flow. Accordingly, the influence of thickness and incidence, as well as Reynolds number is critical in the vicinity of branch points and cut-off points where steady-state solutions can/must change branches/types. The study suggests a correspondence of this bifurcation feature with the lift hysteresis and other aerodynamic anomalies observed from wind-tunnel and numerical studies in subcritical and high-subcriticalReflows.

Dependency of Unsteady Time-Linearized Flutter Investigations on the Steady State Flow Field

2011 ◽  
Author(s):  
Michael Blocher ◽  
Markus May ◽  
Harald Schoenenborn
Keyword(s):  
Steady State ◽  
Steady State Solution ◽  
Elastic Stability ◽  
Compressor Cascade ◽  
Steady State Flow ◽  
State Flow ◽  
Flow Parameters ◽  
Pressure Distributions ◽  
German Aerospace ◽  
École Polytechnique

The influence of the steady state flow solution on the aero-elastic stability behaviour of an annular compressor cascade shall be studied in order to determine sensitivities of the aero-dynamic damping with respect to characteristic flow parameters. In this context two different flow regimes — a subsonic and a transonic case — are subject to the analysis. The pressure distributions, steady as well as unsteady, on the blade surface of the NACA3506 profile are compared to experimental data that has been gained by the Institute of Aeroelasticity of the German Aerospace Center (DLR) during several wind tunnel tests at the annular compressor cascade facility RGP-400 of the Ecole Polytechnique Fe´de´rale de Lausanne (EPFL). Whereas a certain robustness of the unsteady CFD results can be stated for the subsonic flow regime, the transonic regime proves to be very sensitive with respect to the steady state solution.

On the steady-state solution of the M/G/2 queue

1979 ◽  
Vol 11 (01) ◽  
pp. 240-255 ◽  
Author(s):  
Per Hokstad
Keyword(s):  
Steady State ◽  
General Solution ◽  
Laplace Transform ◽  
Queue Length ◽  
Joint Distribution ◽  
Length Distribution ◽  
Steady State Solution ◽  
Queue Length Distribution ◽  
The Difference ◽  
Number Of Customers

The asymptotic behaviour of the M/G/2 queue is studied. The difference-differential equations for the joint distribution of the number of customers present and of the remaining holding times for services in progress were obtained in Hokstad (1978a) (for M/G/m). In the present paper it is found that the general solution of these equations involves an arbitrary function. In order to decide which of the possible solutions is the answer to the queueing problem one has to consider the singularities of the Laplace transforms involved. When the service time has a rational Laplace transform, a method of obtaining the queue length distribution is outlined. For a couple of examples the explicit form of the generating function of the queue length is obtained.

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