Papers by Keyword: Surface Wave

Abstract: The effect of waving bottom on the fluid surface wave was investigated. Starting from the basic equations of potential flow theory and boundary conditions, we used the multiple scales perturbation method to deduce fluid surface waves satisfy the first-order approximate equation and second-order approximate equation. Under the second-order approximation, the fluid surface waveform was simulated with the Matlab in the presence of different waving bottom form. The results show that there are three solitary waves on the surface of the fluid. With the development of time, the amplitude of each solitary wave has not changed. It seems that they are not affected each other and propagate independently. So it suggests that the waving bottom is effective for maintaining surface wave energy balance income and expenditure in spreading process.

Abstract: Propagation properties of TE mode for the symmetric waveguide made of left-handed material surrounded by metal substrate- and coat- layers are studied. The guidance conditions of TE mode is deduced by transmission matrix. Using graphical method, different propagation modes and corresponding transverse profiles of electric field are analyzed. It is found that the fundamental mode TE0 does not exists, such waveguide can support surface wave modes. There is a significant effect on transverse profile of order m and so on. This result will play a theoretical guidance for the research of waveguide containing left-handed materials.

Abstract: the piezoelectric and piezomagnetic effects and the influence of short and open circuit on the surface wave speed are investigated in this paper. First, the elastic, piezoelectric and piezomagnetic coefficients in the considered ordinate system are obtained by Bonde transformation from that in the crystal axes ordinate system. Then, the equation which surface wave speed satisfies is derived from the free traction condition on the surface of piezoelectric and piezomagnetic half space with consideration of short and open circuit case. Some numerical examples are given and the piezoelectric and piezomagnetic effects and the influence of short and open circuit on the surface wave speed are shown graphically.

Abstract: A kind of single inlet swirl atomizer is set to adjust the inlet location and the length of the outlet for an optimization spray angle and uniformity in this literature.Stationary wave theory is used to describe the results of spray quality.Experimental and theoretical analysis show that using property machining process size, single inlet swirl nozzles can achieve the optimized quality of atomization (spray cone angle of 55 °and more, skewness of spray cone center below 5 ° ).

Abstract: In the paper, with the change of the relation between the Bond numbers and 1/3, the different control equations with different dispersion item was obtained for the surface wave of film under uneven bottom. The equation under tension and bottom was reduced from the potential flow theory with the little parameter perturbation technique, and then was solved by using the numerical method. The waterfall of the surface wave was simulated with Matlab software. The results show that different surface tension and different bottom has different effect on the film surface.

Abstract: Surface cracks are the most common defects in structures. Ultrasonic has been widely used as a non-destructive evaluation technology in the case of crack characterization. In this investigation, surface waves are applied to a steel block with artificial slots to characterize the crack depth. A series of test specimen with different depths of surface crack ranging from 4mm to 10mm was fabricated. The depth of the surface crack was evaluated using the pitch-catch ultrasonic technology. In this work, 2.25 MHz, 5 MHz and 10 MHz of incident waves were employed to investigate the effect of frequency on the crack depth detection. Experimental test results show that the accuracy of crack depth detection is increasing with the increase of frequency.

Abstract: Applying linear marine hydrodynamics theory, the Kelvin wave source Green function of steady motion in finite depth was decomposed to three parts: array of simple Rankine sources, local distribution and wave part. Both at subcritical and supercritical speed, the singularity of integral function were eliminated by different integral path. The Kelvin source was distributed on the surface of ship by panel method, and the ship pressure distribution and wave pattern of ship in finite depth were calculated. The difference and connection between finite and infinite depth results were compared. It can provide the theoretical arithmetic base of improving the ship seaworthiness, increasing the speed and optimization of ship in river and offshore strip.

Abstract: Non-reciprocal component is very important for nanophotonic circuit. In this article, we demonstrate that a kind of unidirectional surface state can exist in various interfaces between magnetized gyrotropic material and other medium. Since this type of modes is not limited by bandgap as those in photonic crystals, it provides possibilities for making broad-spectrum non-reciprocal devices.

Abstract: High-impedance ground plane (HIGP) is applied in the design of rectangular waveguide end-slot phased array. The benefits of using such a HIGP are related to the suppression of surface waves because of its obvious frequency bandgap and, therefore, the scan blindness could be eliminated. Both of the bandgap curve of the HIGP structure and the scan properties of the phased arrays have been calculated. The elimination of scan blindness is obtained.

Abstract: FDTD method is used to simulate SPPs in the Kretschmann structure. It is observed that the surface plasmon wave propagates not only with the attenuation but also with the oscillation. This paper explains the reasons for this phenomenon: the oscillation is caused by coupling of SPPs in the metal - air interface and dielectric - metal interface.