Cylindrical Line Research Articles

An electromagnetic model for multiconductor connectors

An electromagnetic model for the response of multiconductor connectors is presented. The model is based on the canonical problem of the electromagnetic response of a thin circumferential slot in the shield of a cylindrical multiconductor transmission line (MTL). The problem is formulated for a shielded MTL of arbitrary cross section with impressed sources driving the interior of the MTL. The problem of interior-to-exterior coupling is solved by treating the slot as a thick aperture in the shield. The equivalence principle is used to divide the original problem into three separate parts. Two coupled integral equations are obtained for the equivalent surface magnetic currents, which are solved by the method of moments, and equivalent networks are presented. The equivalent networks consist of three generalized admittances, one of which is interpreted in terms of a connector admittance. >

Slotted waves of coupled cylindrical and mirror slotted lines and directional couplers based on them

Slotted waves of coupled cylindrical and mirror slotted lines and directional couplers based on them

Analysis of a Class of Cylindrical Multiconductor Transmission Lines Using an Iterative Approaclh

A class of cylindrical multiconductor transmission lines is theoretically analyzed, and useful parameters, e.g., characteristic impedance and effective dielectric constant, are derived. Discretization of the continuous functions and exploitation of the periodicity of the cylindrical structure lead to a discrete convolution which can be carried out numerically rigorously and efficiently using the FFT algorithm. An iterative technique is employed in the spectral domain to derive the solution of integral equations for the charge distribution. Numerical results are presented and compared with available data.

Experimental investigation of the distribution of the electric field in cylindrical and mirror slotted lines

Experimental investigation of the distribution of the electric field in cylindrical and mirror slotted lines

Experimental study of discontinuities in a cylindrical slot line

Experimental study of discontinuities in a cylindrical slot line

Bond Graph Models for Fluid Networks Using Modal Approximation

Modal bond graph representations of the dissipative model of rigid, cylindrical fluid transmission lines with laminar flow are developed. Modal approximation techniques are used for both hydraulic and pneumatic lines. The modeling and simulation procedures for fluid networks coupled with nonlinear and dynamic systems are greatly facilitated using bond graphs. The physical interpretation of the model is preserved in this approach. Simulation results for hydraulic single lines are compared with results derived by the quasi-method of characteristics. The simulation results for fluid networds for various line and termination configurations are illustrated.

Nonexistence of quasilaminar equilibria in cylindrical magnetically insulated lines

It has previously been shown for nonrelativistic voltages (i.e., much less than 500 kV) that a quasilaminar, cold-fluid, magnetically insulated equilibrium does not exist on coaxial cylindrical lines for which (1) the magnetic field is azimuthal, (2) electron emission at the cathode is space- charge-limited, and (3) the cathode lies within the anode. Since it is expected to encounter this configuration frequently in practice, and because such lines typically operate at voltages above 500 kV, the previous analysis has been extended to take account of relativistic and sheath diamagnetic effects. Despite their inclusion it is found that the nonexistence of this type of equilibrium state continues to hold at the higher voltage levels.

Turbulent flow device for testing hydrophones

A turbulent flow apparatus for laboratory use that provides a turbulent f field around the circumference of a cylindrical line array. The apparatus enables an evaluation of the response characteristics of the acoustic sensors in the line array to the resultant pressure field similar to the one present when the line array is towed at sea or is subject to flow. The apparatus includes a small cylindrical chamber which can be assembled around the portion of a line array under test. Water from a source is supplied at one end of the chamber through inlets and a turbulent flow is attained by the water as it comes out of the opposite end of the chamber. The portion of the array containing the hydrophones under test are placed in the water to simulate the flow environment encountered at sea.

Acoustic loading effects on a cylindrical line array resulting from an internal concentric compliant tube baffle

The performance of a cylindrical line of array of radially, vibrating ceramic rings when liquid filled for pressure compensation is affected by the acoustic loading of the internal cavity. This internal loading may be varied by the use of a concentric baffle of compliant tubes. This paper presents experimental data showing variations in acoustic loading resulting from various sizes and numbers of tubes used in the baffle and an approximate method of calculating these effects.

Nye harpunfund

Nye harpunfund

Transient Response of Fluid Lines Including Frequency Modulated Inputs

In this paper, analytic descriptions for the step and impulse responses of the fluid in rigid cylindrical lines are obtained in the time domain. In all cases, the fluids considered are Newtonian liquids or perfect gases, with the effects of laminar viscous dissipation and heat transfer taken into account. In particular, a power series expansion is used to solve the partial differential equations of small amplitude signal propagation. With the advent of carrier techniques in fluid systems the study of the transmission of frequency-modulated signals in fluid-filled lines is needed. Recognizing this need, an analysis of the response of fluid-filled lines to a step modulation of carrier frequencies is presented. Experimental measurements of the step response of air filled lines are also given. An effect uncovered by the experimental work is the nonlinearity of the signals at signal amplitudes, unexpectedly as low as one percent of the mean pressure.

Optical Imaging of the Cross Section of a Microwave Acoustic Beam in Rutile by Bragg Diffraction of a Laser Beam

This letter reports some results of an analysis, based on a wave-optical formulation, of the farfield Bragg diffraction from a cylindrical line source light beam by a line-source acoustic wave. The properties of the diffracted light that are relevant to the problem of optically viewing or imaging the acoustic fields of plane or cylindrical transducers are discussed. The most important of these properties are as follows: (1) A line light source exists for the diffracted light and is either real or virtual depending upon the location of the acoustic source relative to the light source; (2) the location of this line source for the diffracted light has a geometrical correspondence to the acoustic source location; and (3) the phase and amplitude of the acoustic source is preserved in the diffracted line source. As the field of a plane or cylindrical transducer can be represented as a superposition of a set of line-source waves, it follows that the total diffracted field is either a real or virtual image of the acoustic field. In either case, a real, enlarged image can be formed by the used of proper lenses. A description and examples of results are given for an experiment in imaging the transverse section of two parallel but physically separated 923 MHz microwave acoustic beams in a rutile crystal. The image resolution obtainable is discussed and compared for the experimental conditions with that obtained using a finely focused, mechanically scanned light probe.

Measurement of Dose Rates of a High-Level Gamma Irradiation Facility

LiF thermoluminescent dos meters were used to measure the dose rates in a high-level gamma irradiation facility which provides a wide range in dose level and various irradiation areas. A comparison of the discrepancies between observed data and calculated data based on a cylindrical source, point source, and line source is included.

Step Responses of Liquid Lines With Frequency-Dependent Effects of Viscosity

Universal step-response plots are given from theoretical considerations for rigid cylindrical lines containing a compressible Newtonian laminar-flow liquid. The pressure and flow step inputs and pressure and flow outputs for semi-infinite lines can, with the principle of superposition, be used to estimate the responses of a network of lines, terminations, and so on, for any transient input. Where possible, analytic expressions were found for these step responses, but in a certain region of each curve complex numerical routines based on the analytic frequency response were necessary. Analytical expressions are based on propagation and characteristic impedance operators published earlier by one of the authors.

Increased Bandwidth for Deep-Submergence Transducers

A technique is described for eliminating the bandwidth degradation usually associated with piezoelectric cylindrical radiators that have been liquid filled for hydrostatic-pressure compensation. This technique utilizes an acoustically stiff internal structure to control the impedance presented to the vibrator at the internal ceramic-liquid interface. By controlling this interface impedance, it is possible to eliminate the effective mass contribution from the pressure compensating fluid. A comparison between theoretical and experimental data is presented for several units utilizing this technique. One of the units discussed is a cylindrical line transducer resonant at 2.5 kc/sec with a bandwidth greater than 1600 cps and an efficiency greater than 60%. The unit is pressure-compensated for deep-submergence operation with no degradation in performance.

Nonuniformities in Laminated Transmission Lines

The effect on transmission properties of certain nonuniformities in laminated transmission lines has been calculated by a perturbation method. Particular cases hare been calculated, including the effect of varying radius of curvature in a cylindrical Clogston line, the effect of systematic variation in effective dielectric constant and the effect of random variation in layer thickness where the nonuniformities are known only through statistical properties. In one Clogston line where measurements of nonuniformity have been made the method predicts a transmission impairment in substantial agreement with observations.