THE E-PLANE RADIATION PATTERN OF SHORT ELECTROMAGNETIC HORNS OF LARGE APERTURE

1947 ◽  
Vol 25a (6) ◽  
pp. 315-321 ◽  
Author(s):  
G. A. Woonton ◽  
J. G. Tillotson
Keyword(s):  
Electromagnetic Field ◽  
Diffraction Pattern ◽  
Radiation Pattern ◽  
Wave Length ◽  
Angular Position ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electric Vector ◽  
Theoretical Predictions ◽  
Good Agreement

The relation between the power received by a short, rectangular, electromagnetic horn, and its angular position in a plane electromagnetic field can be calculated, for rotation in the plane of the electric vector, from ordinary optical theory by assuming that the aperture produces at the throat a Fresnel diffraction pattern appropriate to the angular position of the aperture. Experimental results for four horns of slant lengths 25, 50, 100, and 176 cm., but all of the same aperture, 10λ to a side at a wave length of 3.2 cm., are in good agreement with the theoretical predictions at angles up to [Formula: see text] radian from the axis, for slant lengths down to 50 cm. but not down to 25 cm.

Explicit formulation for the axial collapse of a pipe during drilling

2010 ◽  
Vol 224 (8) ◽  
pp. 1547-1549
Author(s):  
A Almasi
Keyword(s):  
Closed Form ◽  
Plastic Hinge ◽  
Variable Length ◽  
Experimental Results ◽  
Displacement Curve ◽  
Explicit Formulation ◽  
Theoretical Predictions ◽  
Hinge Zone ◽  
Good Agreement

New closed-form expressions are introduced for ax-symmetric progressive axial collapse of pipes that use a plastic folding mechanism based on variable length of an active plastic hinge zone. A procedure for determination of a load—displacement curve of axial pipe collapse is presented. Theoretical predictions give a good agreement with the experimental results owing to the influence of presented new refinements.

Measurement of sheath characteristics in the presence of convection and ionization

1996 ◽  
Vol 74 (9-10) ◽  
pp. 671-675 ◽  
Author(s):  
R. M. Clements ◽  
J. R. Dawe ◽  
S. A. H. Rizvi ◽  
P. R. Smy
Keyword(s):  
Boundary Layer ◽  
Plasma Electron ◽  
Experimental Results ◽  
Ion Density ◽  
Current Voltage ◽  
Planar Grid ◽  
Theoretical Predictions ◽  
Flame Plasma ◽  
Theoretical Paper ◽  
Good Agreement

A flame plasma whose electron and (or) ion density can be varied over several orders of magnitude is constrained to flow perpendicular to a planar grid Langmuir probe. The probe is biased negative to the plasma, and the current–voltage characteristics and the thickness of the ion sheath formed at the probe are measured. The level of the electron and (or) ion density is set within a range at which the probe current due to thermal ionization throughout the sheath is comparable with the current of ions convected into the sheath. The experimental results are compared with the predictions of a recent theoretical paper that calculates the effect of recombination upon the characteristics of planar, cylindrical, and spherical probes with boundary layer sheaths. The theoretical predictions and experimental results for an idealized planar configuration show good agreement over wide ranges of variation of probe bias and plasma electron and (or) ion density. This verification of the theoretical planar electrode – perpendicular-flow model, which is the basis for all three boundary layer relations, is seen as providing strong backing for these relations, which have application to ionization measurements in various forms of recombinant plasma.

Paper 31: Capsule-Pipeline Flow—A Theoretical Study

1969 ◽  
Vol 184 (7) ◽  
pp. 89-100
Author(s):  
V. K. Garg ◽  
G. F. Round
Keyword(s):  
Theoretical Study ◽  
Theoretical Solution ◽  
Experimental Results ◽  
Free Flow ◽  
Average Flow ◽  
Pipe System ◽  
Liquid Carrier ◽  
Pipeline Flow ◽  
Theoretical Predictions ◽  
Good Agreement

Theoretical predictions of the behaviour of various parameters governing the free flow of a single, very long, denser-than-liquid carrier, cylindrical capsule in a horizontal pipeline are reported in this paper. The study was carried out for average flow velocities of approximately 1–10 ft/s in pipes of diameters 4, 6, 12, and 24 in with diameter ratios varying from 0·9 to 0·99. While two liquid carriers—water and an oil ( μ = 10 cP and sp. gr. = 0·85)—were used, the eccentricity of the capsule-pipe system was fixed at 0·999. The theoretical solution was found to be in good agreement with the experimental results.

The bursting of a charged cylindrical film

1972 ◽  
Vol 328 (1575) ◽  
pp. 529-539 ◽  
Keyword(s):  
Experimental Data ◽  
Finite Length ◽  
Experimental Results ◽  
Exact Calculation ◽  
Conducting Film ◽  
Half Wavelength ◽  
Theoretical Predictions ◽  
Long Cylinder ◽  
Good Agreement

This paper is a sequel to Sir Geoffrey Taylor’s study of the bursting of an electrified cylindrical conducting film. Taylor described experiments in which the voltages, at which the film becomes statically unstable, were observed for various lengths of film. These results were compared with the theoretical predictions for disturbances on an infinitely long cylinder having a wavelength equal to the length of film used. It is shown here that a transition in the mode of bursting from an axisymmetric whole wavelength mode to a lateral half wavelength mode is to be expected and that the experimental data conform with this transition. An exact calculation of the modes for a film of finite length is also given here and the resulting theoretical predictions of instability and bursting voltages are in very good agreement with the experimental results.

Using Superhydrophobic SU-8 Film as the Dielectric for Electrowetting-on-Dielectric

2018 ◽  
Vol 281 ◽  
pp. 604-609
Author(s):  
Yu Hao Piao ◽  
Wei Qiang Wang
Keyword(s):  
Contact Angle ◽  
Dielectric Layer ◽  
Superhydrophobic Surface ◽  
High Performance ◽  
Apparent Contact Angle ◽  
Experimental Results ◽  
Electrowetting On Dielectric ◽  
Dc Voltage ◽  
Theoretical Predictions ◽  
Good Agreement

In this paper, we study the electrowetting effect of superhydrophobic SU-8 film as the dielectric for Electrowetting-on-Dielectric (EWOD). The change of apparent contact angle (APCA) on superhydrophobic surface in electrowetting systems was measured and analyzed using a modified Lippmann-Yong equation. The variation of APCA between droplet and device surface under various DC voltage and AC voltage of different frequencies was fully experimented. The experimental results were in good agreement with the theoretical predictions. This study shows the potential of using superhydrophobic SU-8 film as the dielectric layer in high-performance EWOD devices.

Effect of Textures on the Nanomechanical Properties of Nanocrystalline Fe-50%Ni Foil

2006 ◽  
Vol 15-17 ◽  
pp. 923-928
Author(s):  
Jong Kweon Kim ◽  
Shi Hoon Choi ◽  
Yong Bum Park
Keyword(s):  
Elastic Modulus ◽  
Sample Thickness ◽  
Experimental Results ◽  
Nanoindentation Test ◽  
Specimen Thickness ◽  
Strong Decrease ◽  
Nanomechanical Properties ◽  
Texture Change ◽  
Theoretical Predictions ◽  
Good Agreement

The textures and nanomechanical properties of nanocrystalline Fe-50wt%Ni foil fabricated by using an electroforming method were investigated. The as-deposited texture was characterized by major <100>//ND and minor <111>//ND fibre components. Annealing of the as-deposited specimen resulted in the texture change that the <111>//ND fibre texture developed strongly with decreasing <100>//ND intensity. The elastic modulus and hardness were investigated by nanoindentation test, and these experimental results were compared with the theoretical predictions based on an elastic self-consistent (ESC) polycrystal model. Annealing led to an increase in the elastic modulus and a strong decrease in the hardness. At the low ratio of indentation depth to the specimen thickness, the theoretical predictions of the elastic modulus in the sample thickness direction showed a good agreement with experimental results.

scholarly journals AN INCLINED-PLATE WAVE GENERATOR

1978 ◽  
Vol 1 (16) ◽  
pp. 21
Author(s):  
Frederick Raichlen ◽  
Jiin-Jen Lee
Keyword(s):  
Numerical Method ◽  
Wave Length ◽  
Experimental Results ◽  
Length Ratio ◽  
Constant Depth ◽  
Inclined Plate ◽  
Plate Wave ◽  
Wave Generator ◽  
Good Agreement

A numerical method for determining the characteristics of waves generated by a hinged inclined-plate wave generator operating in a constant depth channel is discussed. The analysis is in reasonably good agreement with experimental results. The results indicate the sloping generator operating under certain conditions is completely inefficient, i.e., for a given stroke and depth-to-wave-length ratio, very small waves are produced; for other wave periods for the same conditions significantly larger waves are generated.

Added Resistance CFD Analysis of the KVLCC2 With the Naval Hydro Pack

2019 ◽  
Author(s):  
V. Vukčević ◽  
I. Gatin ◽  
G.-H. Kim ◽  
H. Jasak
Keyword(s):  
Open Source Software ◽  
Turbulence Modeling ◽  
Wave Length ◽  
Experimental Results ◽  
Head Wave ◽  
Cfd Analysis ◽  
Added Resistance ◽  
Sst Model ◽  
Time Required ◽  
Good Agreement

Abstract A CFD analysis of added resistance of a KVLCC2 ship model is presented in this paper. The Naval Hydro Pack, an open source software library for computational naval hydrodynamics based on OpenFOAM is used to perform the simulations. Ten head wave cases are considered in this study ranging from short waves to long waves (wave length to length between perpendiculars ranging from 0.3 to 2). During the initial stages of our research, we had noticed significant over-prediction of added resistance compared to experimental results. After thorough analysis, the issue was found to be related to inadequate turbulence modeling using the standard k-ω SST model. Using the free surface sensitised model, the prediction of the added resistance improves significantly Compared to the experimental results, majority of the cases with different wave lengths have errors smaller than several percent. In addition to added resistance, heave and pitch motion amplitudes are compared to recent experimental results by Park et al. [1], showing good agreement. CPU time required to perform the computations is also discussed.

scholarly journals Theoretical and Experimental Study of Split Semi Horse Shoe Structure

2018 ◽  
Vol 7 (5) ◽  
pp. 131-136
Author(s):  
G. Singh ◽  
S. S. Pattnaik
Keyword(s):  
Experimental Study ◽  
Theoretical Analysis ◽  
Equivalent Circuit ◽  
Radiation Pattern ◽  
Patch Antenna ◽  
Circuit Theory ◽  
Experimental Results ◽  
Effective Parameters ◽  
Metamaterial Structure ◽  
Good Agreement

In this paper a new planar metamaterial structure that looks like semi-horse shoe in shape (SSHSS) is designed and simulated. Theoretical analysis of proposed structure done using equivalent circuit theory. Medium effective parameters are extracted using modified NRW approach which proved the metamaterial property of the new unit cell. Radiation pattern, directivity and gain of the new structure were illustrated which gives the possibility of using SSHSS as the antenna. Proposed structure shows multiband characteristics. This antenna shows high directivity (7.92 dBi, 7.86 dBi, 10.11 dBi) and moderate gain (2.55 dBi, 3.90 dBi, 5.07 dBi) at 5.83 GHz, 8.41 GHz, 10.68 GHz respectively. RT duroid is used for fabrication of prototype of the proposed structure. This new structure can be used as metamaterial inspired antenna as well as normal patch antenna. Experimental results shows good agreement with simulated and theoretical results.The proposed structure has been simulated using IE3D electromagnetic simulator.

scholarly journals Theory of efficient shell implosions

1989 ◽  
Vol 7 (2) ◽  
pp. 189-205 ◽  
Author(s):  
Masakatsu Murakami ◽  
Katsunobu Nishihara ◽  
Hideaki Takabe
Keyword(s):  
Theoretical Model ◽  
Neutron Yield ◽  
Mass Density ◽  
Coupling Efficiency ◽  
Experimental Results ◽  
Moderate Intensity ◽  
Ion Temperature ◽  
Hollow Shell ◽  
Theoretical Predictions ◽  
Good Agreement

A theoretical model of spherical ablative implosion is presented. The implosion performances such as the target coupling efficiency are estimated from the aspect ratio and initial mass density of a target shell, provided the laser is fixed at moderate intensity for a given wavelength. The model is applied to the experimental results obtained for both plastic hollow shell targets and DT gas-filled GMB targets by use of the twelve-beam green GEKKO XII laser. In addition to the target coupling efficiency, it is shown for the gas-filled targets that the theoretical predictions of neutron yield, ion temperature, and fuel ρ and ρR are in good agreement with the experimental results. Reduction of neutron yields due to irradiation nonuniformity is also discussed, and 5% of absorption nonuniformity is found to be required for explaining the discrepancies in neutron yield between the experiments and the theory.

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