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Calculating the shading reduction coefficient of photovoltaic system efficiency using the anisotropic sky scattering model 被引量:2
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作者 Bin Hu Jiawei Wu +2 位作者 Peng Li Wei Sun Jinyu Xiao 《Global Energy Interconnection》 EI CAS CSCD 2022年第4期375-384,共10页
The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar r... The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar radiation intensity on the surface of the PV array during the shaded period is simulated,combined with the voltage-current characteristics of the PV modules,and the shadow occlusion operating mode of the PV array is modeled.A method for calculating the loss coefficient of front shadow occlusion based on the division of the PV cell string unit and Hay anisotropic sky scattering model is proposed.This algorithm can accurately evaluate the degree of influence of the PV array layout,wiring mode,array spacing,PV module specifications,and solar radiation on PV power station system efficiency.It provides a basis for optimizing the PV array layout,reducing system loss,and improving PV system efficiency. 展开更多
关键词 Shading reduction coefficient System efficiency Hay anisotropic sky scattering model PV cells string unit
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The Modified Friction and Diffusion Coefficients of Fokker-Planck Equation and Relaxation Rates for Non-Maxwellian Scattering
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作者 项江 李定 蔡辉山 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第6期661-670,共10页
In this paper, a new method to derive the Fokker-Planck coefficients defined by a non-Maxwellian velocity distribution function for the field particles is presented. The three- fold integral and the new Debye cutoff p... In this paper, a new method to derive the Fokker-Planck coefficients defined by a non-Maxwellian velocity distribution function for the field particles is presented. The three- fold integral and the new Debye cutoff parameter, which were introduced by CHANG and LI, are applied. Therefore, divergence difficulties and the customary replacement of relative velocity g by thermal velocity vth are naturally avoided. The probability function P(v, Av) for non- Maxwellian scattering is derived by the method of choosing velocity transfer Av, which is a true measure of collision intensity, as an independent variable. The method enables the difference between small-angle scattering and small-momentum-transfer collisions of the inverse-square force to be well clarified. With the help of the probability function, the Fokker-Planck coefficients are obtained by a normal original Fokker-Planck approach. The friction and diffusion coefficients of the Fokker-Planck equation are modified for non-Maxwellian scattering and are used to investigate the relaxation processes for the weakly coupled plasma. The profiles of the relaxation rates show that the slowing down and deflection processes are weakened in the conditions of non-Maxwellian scattering. 展开更多
关键词 Fokker-Planck coefficients non-Maxwellian velocity distribution field particles velocity distribution small-angle scattering small-momentum-transfer collisions
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Measurement and analysis of ozone, ultraviolet B and aerosol light scattering coefficients in the Arctic
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作者 LAI Xin BIAN Lingen +1 位作者 LU Changgui TANG Jie 《Advances in Polar Science》 2011年第4期260-265,共6页
Tropospheric ozone (O3), ultraviolet B (UVB) radiation and aerosol light scattering coefficients (SC) were investigated on a cruise ship during the fourth Chinese National Arctic Research Expedition from July 1 ... Tropospheric ozone (O3), ultraviolet B (UVB) radiation and aerosol light scattering coefficients (SC) were investigated on a cruise ship during the fourth Chinese National Arctic Research Expedition from July 1 September 20, 2010. The results showed that O3, UVB and SC decreased with increasing latitude, with minimum values recorded in the central Arctic Ocean. Average O3 concentrations were 15.9 ppbv and 15.1 ppbv in the Bering Sea and Arctic Ocean, respectively. Ozone concentrations increased to 17.5 ppbv in the high Arctic region. Average UVB values were 0.26 W.m-2 and 0.14 W.m-2 in the Bering Sea and Arctic Ocean, respectively. The average SC in the Bering Sea was 4.3 M.m-1, more than twice the value measured in the Arctic Ocean, which had an average value of 1.7 M.m-1. Overall, UVB and SC values were stable in the central Arctic Ocean. 展开更多
关键词 Arctic Ocean tropospheric ozone ultraviolet B radiation aerosol light scattering coefficient
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Measurement of Raman scattering gain coefficient in large-aperture DKDP crystals irradiated by 351 nm pulses
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作者 Han Wei Xiang Yong +9 位作者 Wang Fang Zhou Lidan Feng Bin Li FUCluan Zhao Junpu Zheng Kuixing Zhu Qihua Wei Xiaofeng Zheng Wanguo Gong Mali 《强激光与粒子束》 EI CAS CSCD 北大核心 2016年第2期24-28,共5页
Transverse stimulated Raman scattering (TSRS) gain coefficient in a large aperture 65% deu terated potassium dihydrogen phosphate (DKDP) is measured at 351 nm. The measurement involves the use of an optical fiber ... Transverse stimulated Raman scattering (TSRS) gain coefficient in a large aperture 65% deu terated potassium dihydrogen phosphate (DKDP) is measured at 351 nm. The measurement involves the use of an optical fiber sensor system to detect Raman scattering light in the DKDP crystal. A Raman scattering gain coefficient of 0. 109 cm/GW is obtained and will be used to set upper limit of the DKDP crystals in our laser fa cility to avoid the TSRS induced energy loss and laser damage. The effect of bulk damage on growth behavior of TSRS is also examined and it is found that bulk damage has little impact on the TSRS growth. Thus the influ ence of bulk damage on the measurement of TSRS gain coefficient can be ignored. 展开更多
关键词 transverse stimulated Raman scattering GEN PHOSPHATE UV lasergain coefficient DEUTERATED POTASSIUM dihydro
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Fast Single Image Haze Removal Method for Inhomogeneous Environment Using Variable Scattering Coefficient
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作者 Rashmi Gupta Manju Khari +4 位作者 Vipul Gupta Elena Verdú Xing Wu Enrique Herrera-Viedma Rubén González Crespo 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第6期1175-1192,共18页
The images capture in a bad environment usually loses its fidelity and contrast.As the light rays travel towards its destination they get scattered several times due to the tiny particles of fog and pollutants in the ... The images capture in a bad environment usually loses its fidelity and contrast.As the light rays travel towards its destination they get scattered several times due to the tiny particles of fog and pollutants in the environment,therefore the energy gets lost due to multiple scattering till it arrives its destination,and this degrades the images.So the images taken in bad weather appear in bad quality.Therefore,single image haze removal is quite a bit tough task.Significant research has been done in the haze removal algorithm but in all the techniques,the coefficient of scattering is taken as a constant according to the homogeneous atmosphere but in real time this does not happen.Therefore,this paper introduces a simple and efficient method so that the scattering coefficient becomes variable according to the inhomogeneous environment.Then,this research aims to remove the haze with the help of a fast and effective algorithm i.e.,Prior Color Fading,according to the inhomogeneous environmental properties.Thereby,to filter the depth map,the authors used a weighted guided image filtering which removes the drawbacks of guided image filter.Afterwards the scattering coefficient is made variable according to the inhomogeneous atmosphere and then the Simple Color Balance Algorithm is applied so that the readability property of images can be increased.The proposed method tested on various general outdoor images and synthetic hazy images and analyzed on various parameters Mean Square Error(MSE),Root Mean Square Error(RMSE),Peak Signal to Noise Ratio(PSNR),Mean Structural Similarity(MSSIM)and the Universal Objective Quality Index(UQI).Experimental results for the proposed method show that the proposed approach provides better results as compared to the state-of-the-art haze removal algorithms. 展开更多
关键词 Image dehazing scattering coefficient simple color balance inhomogeneous environment
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Direct evidence for efficient scattering of suprathermal electrons by whistler mode waves in the Martian magnetosphere
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作者 Tong Li Si Liu +8 位作者 Chang Yang FuLiang Xiao HongMing Yang Sai Zhang ZhongLei Gao Qian He QingHua Zhou QiWu Yang YiHua He 《Earth and Planetary Physics》 CAS CSCD 2023年第6期607-614,共8页
Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which ... Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which enhanced whistler mode waves(~10^(−11) V^(2)/m^(2)/Hz)with frequency of 0.1 f_(ce)-0.5 f_(ce) occurred,based on MAVEN data,exactly corresponding to a significant decrease of suprathermal electron fluxes.The diffusion coefficients are calculated by using the observed electric field wave spectra.The pitch angle diffusion coefficient can approach 10^(−2) s^(−1),which is much larger,by~100 times,than the momentum diffusion coefficient,indicating that pitch angle scattering dominates the whistler-electron resonance process.The current results can successfully explain the dropout of the suprathermal electrons in this event.This study provides direct evidence for whistler-driven electron losses in the Martian magnetosphere. 展开更多
关键词 whistler mode waves diffusion coefficients electron scattering Martian magnetosphere
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Scattering Properties of Atmospheric Aerosols over Lanzhou City and Applications Using an Integrating Nephelometer 被引量:6
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作者 张武 胡波 +3 位作者 陈长和 杜萍 张镭 冯广泓 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第6期848-856,共9页
The data, measured by a three-wavelength Integrating Nephelometer over Lanzhou City during the winters of 2001/2002 and 2002/2003 respectively, have been analyzed for investigating the scattering properties of atmos... The data, measured by a three-wavelength Integrating Nephelometer over Lanzhou City during the winters of 2001/2002 and 2002/2003 respectively, have been analyzed for investigating the scattering properties of atmospheric aerosols and exploring their relationship and the status of air pollution. The aerosol particle volume distribution is inverted with the measured spectral scattering coe?cients. The results show that the daily variation of the aerosol scattering coe?cients is in a tri-peak shape. The average ratio of backscattering coe?cient to total scattering coe?cient at 550 nm is 0.158; there exists an excellent correlation between the scattering coe?cients and the concentration of PM10. The average ratio of the concentration of PM10 to the scattering coe?cients is 0.37 g m?2, which is contingent on the optical parameters of aerosol particles such as the size distribution, etc.; an algorithm is developed for inverting the volume distribution of aerosol particles by using the histogram and Monte-Carlo techniques, and the test results show that the inversion is reasonable. 展开更多
关键词 three-wavelength Integrating Nephelometer aerosol spectral scattering coefficient PM10 particle volume distribution
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Oblique Water Wave Scattering by Bottom Undulation in a Two-layer Fluid Flowing Through a Channel 被引量:4
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作者 Smrutiranjan Mohapatra Swaroop Nandan Bora 《Journal of Marine Science and Application》 2012年第3期276-285,共10页
The problem of oblique wave (internal wave) propagation over a small deformation in a channel flow consisting of two layers was considered. The upper fluid was assumed to be bounded above by a rigid lid, which is an... The problem of oblique wave (internal wave) propagation over a small deformation in a channel flow consisting of two layers was considered. The upper fluid was assumed to be bounded above by a rigid lid, which is an approximation for the free surface, and the lower one was bounded below by an impermeable bottom surface having a small deformation; the channel was unbounded in the horizontal directions. Assuming irrotational motion, the perturbation technique was employed to calculate the first-order corrections of the velocity potential in the two fluids by using Green's integral theorem suitably with the introduction of appropriate Green's functions. Those functions help in calculating the reflection and transmission coefficients in terms of integrals involving the shape ftmction c(x) representing the bottom deformation. Three-dimensional linear water wave theory was utilized for formulating the relevant boundary value problem. Two special examples of bottom deformation were considered to validate the results. Consideration of a patch of sinusoidal ripples (having the same wave number) shows that the reflection coefficient is an oscillatory function of the ratio of twice the x-component of the wave number to the ripple wave number. When this ratio approaches one, the theory predicts a resonant interaction between the bed and the interface, and the reflection coefficient becomes a multiple of the number of ripples. High reflection of incident wave energy occurs if this number is large. Similar results were observed for a patch of sinusoidal ripples having different wave numbers. It was also observed that for small angles of incidence, the reflected energy is greater compared to other angles of incidence up to π/ 4. These theoretical observations are supported by graphical results. 展开更多
关键词 two-layer fluid oblique waves wave scattering reflection coefficient transmission coefficient linear water wave theory perturbation technique Bottom Undulation
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Wind speed scaling and the drag coefficient 被引量:1
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作者 WEN Fan GAO Zhiyi +1 位作者 WU Ziku Lü Hongmin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2005年第4期29-42,共14页
Wind speed scaling in similarity law in wind-generated waves and the drag coefficient are studied. In analyzing the data in the wind wave channel, it is found that the u* scaling greatly reduces the scatter in the U1... Wind speed scaling in similarity law in wind-generated waves and the drag coefficient are studied. In analyzing the data in the wind wave channel, it is found that the u* scaling greatly reduces the scatter in the U10 scaling. The u* scaling has much less scatter than the scaling using other wind speeds. The friction velocity seems to play a distinctive role in wave growth. The result is important in the applications of the similarity law and in wave modeling. In theory it gives an insight into the mechanism of wind wave interaction. It is found that wave steepness is important in influencing the drag coefficient. The variability of the coefficients in the currently widely used drag form can be explained by the differences in wave steepness in the observations. A drag coefficient model with wind speed and wave steepness as parameters is proposed. An explanation for Kahma's result that the u, scaling does not reduce the scatter in the U10 scaling is given. 展开更多
关键词 friction velocity SCALING scatter drag coefficient wave steepness
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High frequency S wave envelope synthesis using a multiple non-isotropic scattering model: application to aftershocks from the 2008 Wenchuan earthquake 被引量:1
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作者 Lin Gao Jing Yueling Li Jianbo 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第2期185-194,共10页
Based on the formulation of a multiple non-isotropic scattering process, a characteristic source time is introduced to define the initial impulse width of energy density at the source. An analytical expression of the ... Based on the formulation of a multiple non-isotropic scattering process, a characteristic source time is introduced to define the initial impulse width of energy density at the source. An analytical expression of the initial intensity spectral density of a seismic wave is incorporated into the integral equation of seismic wave energy density. And, a recursive formula of Green's function is derived to obtain the higher order Green's function, which is included to describe the stronger non-isotropic scattering process. Then, the effect of the scattering pattern on the energy density envelope is investigated by the modified scattering theory. Significant differences arc found in the decay of the energy density envelopes with distances using different scattering patterns. The envelope synthesized by the forward dominated scattering pattern is larger than the results obtained by the isotropic and backward dominated scattering pattern. Different scattering patterns are also used to fit the observation data from the aftershocks of the 2008 Wenchuan earthquake. It is concluded that the envelopes synthesized by the forward scattering pattern can match the data better than the isotropic and backward dominated scattering cases, and a new interpretation of the coda wave is given. Finally, using the forward dominated scattering pattern, the envelope broadening of the observed data is reproduced. 展开更多
关键词 non-isotropic scattering coda wave envelope broadening energy transport theory (radiative transfer theory) directional scattering coefficient ground motion
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Wave scattering by undulating bed topography in a two-layer ocean 被引量:2
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作者 P. MAITI B. N. MANDAL U. BASU 《Journal of Marine Science and Application》 2009年第3期183-195,共13页
The problem of wave scattering by undulating bed topography in a two-layer ocean is investigated on the basis of linear theory. In a two-layer fluid with the upper layer having a free surface, there exist two modes of... The problem of wave scattering by undulating bed topography in a two-layer ocean is investigated on the basis of linear theory. In a two-layer fluid with the upper layer having a free surface, there exist two modes of waves propagating at both the free surface of the upper layer and the interface between the two layers. Due to a wave train of a particular mode incident on an obstacle which is bottom-standing on the lower layer, reflected and transmitted waves of both modes are created by the obstacle. For small undulations on the bottom of the lower layer, a perturbation method is employed to obtain first-order reflection and transmission coefficients of both modes for incident wave trains of again both modes in terms of integrals involving the bed-shape fimction. For sinusoidal undulations, numerical results are presented graphically to illustrate the energy transfer between the waves of different modes by the undulating bed. 展开更多
关键词 two-layer ocean wave scattering bottom undulations reflection and transmission coefficients
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Variations in Optical Scattering and Backscattering by Organic and Inorganic Particulates in Chinese Lakes of Taihu, Chaohu and Dianchi 被引量:2
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作者 LYU Heng WANG Qiao +3 位作者 WU Chuanqing ZHU Li LI Yunmei HUANG Jiazhu 《Chinese Geographical Science》 SCIE CSCD 2015年第1期26-38,共13页
This study presents an investigation of the scattering and backscattering properties of the particulates in three Chinese inland lakes(the Taihu Lake, the Chaohu Lake and the Dianchi Lake) based on in situ measurement... This study presents an investigation of the scattering and backscattering properties of the particulates in three Chinese inland lakes(the Taihu Lake, the Chaohu Lake and the Dianchi Lake) based on in situ measurements taken at 119 sites. We modeled the particulate scattering spectra using a wavelength-dependent power-law function, finding that the power-law exponents in the Taihu Lake and the Chaohu Lake differ from those in the Dianchi Lake but are similar to the values in the U.S. coastal waters. In contrast to the open ocean, the backscattering properties in the three lakes can not be determined only from chlorophyll-a concentration. The backscattering ratio spectra exhibit a wavelength dependence feature in all three lakes, generally decreasing with the increasing wavelength. Analysis results of the correlations between the backscattering ratio and the individual water quality parameters clearly show that there are distinctive relations among the three lakes, attributed primarily to different compositions of optically active materials in the three lakes. Analysis of the mass-specific scattering and backscattering coefficients shows that the coefficients at wavelength 532 nm in the Taihu Lake and Chaohu Lake are similar, but they are apparently different from those in the Dianchi Lake. Lastly, Model I multiple linear regressions were adopted to partition the mass-specific cross-sections for scattering and backscattering into organic and inorganic cross-sections to further interpret the scattering and backscattering properties. The relative contribution of organic and inorganic particulates to scattering and backscattering is clearly different among the three lakes. The scattering and backscattering properties of the particulates in the three inland lakes vary significantly based on our collected data. The results indicated that the existing semi-analytical water quality retrieval models of the Taihu Lake can not be applied perfectly to the Chaohu Lake and the Dianchi Lake. 展开更多
关键词 scattering/backscattering coefficient backscattering ratio mass-specific cross-section organic/inorganic particulates Chinese inland lakes
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Scattering of Oblique Surface Waves by the Edge of Small Deformation on a Porous Ocean Bed 被引量:1
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作者 Smrutiranjan Mohapatra 《Journal of Marine Science and Application》 CSCD 2015年第2期156-162,共7页
The scattering of oblique incident surface waves by the edge of a small cylindrical deformation on a porous bed in an ocean of finite depth, is investigated here within the framework of linearized water wave theory. U... The scattering of oblique incident surface waves by the edge of a small cylindrical deformation on a porous bed in an ocean of finite depth, is investigated here within the framework of linearized water wave theory. Using perturbation analysis, the corresponding problem governed by modified Helmholtz equation is reduced to a boundary value problem for the first-order correction of the potential function. The first-order potential and, hence, the reflection and transmission coefficients are obtained by a method based on Green's integral theorem with the introduction of appropriate Green's function. Consideration of a patch of sinusoidal ripples shows that when the quotient of twice the component of the incident field wave number along x-direction and the ripple wave number approaches one, the theory predicts a resonant interaction between the bed and the free-surface, and the reflection coefficient becomes a multiple of the number of ripples. Again, for small angles of incidence, the reflected energy is more as compared to the other angles of incidence. It is also observed that the reflected energy is somewhat sensitive to the changes in the porosity of the ocean bed. From the derived results, the solutions for problems with impermeable ocean bed can be obtained as particular cases. 展开更多
关键词 oblique waves bottom deformation porous bed Green's function perturbation technique reflection coefficient transmission coefficient scattering
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Wave Scattering by Porous Bottom Undulation in a Two Layered Channel 被引量:1
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作者 Sandip Pault Soumen De 《Journal of Marine Science and Application》 2014年第4期355-361,共7页
The scattering of plane surface waves by bottom undulations in channel flow consisting of two layers is investigated by assuming that the bed of the channel is composed of porous material. The upper surface of the flu... The scattering of plane surface waves by bottom undulations in channel flow consisting of two layers is investigated by assuming that the bed of the channel is composed of porous material. The upper surface of the fluid is bounded by a rigid lid and the channel is unbounded in the horizontal directions. There exists only one wave mode corresponding to an internal wave. For small undulations, a simplified perturbation analysis is used to obtain first order reflection and transmission coefficients in terms of integrals involving the shape function describing the bottom. For sinusoidal bottom undulations and exponentially decaying bottom topography, the first order coefficients are computed. In the case of sinusoidal bottom the first order transmission coefficient is found to vanish identically. The numerical results are depicted graphically in a number of figures. 展开更多
关键词 bottom undulations two-layer fluid porous bed reflection and transmission coefficients wave scattering
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Scattering of Surface Water Waves Involving Semi-infinite Floating Elastic Plates on Water of Finite Depth 被引量:1
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作者 Aloknath Chakrabarti Smrutiranjan Mohapatra 《Journal of Marine Science and Application》 2013年第3期325-333,共9页
Two problems of scattering of surface water waves involving a semi-infinite elastic plate and a pair of semi-infinite elastic plates,separated by a gap of finite width,floating horizontally on water of finite depth,ar... Two problems of scattering of surface water waves involving a semi-infinite elastic plate and a pair of semi-infinite elastic plates,separated by a gap of finite width,floating horizontally on water of finite depth,are investigated in the present work for a two-dimensional time-harmonic case.Within the frame of linear water wave theory,the solutions of the two boundary value problems under consideration have been represented in the forms of eigenfunction expansions.Approximate values of the reflection and transmission coefficients are obtained by solving an over-determined system of linear algebraic equations in each problem.In both the problems,the method of least squares as well as the singular value decomposition have been employed and tables of numerical values of the reflection and transmission coefficients are presented for specific choices of the parameters for modelling the elastic plates.Our main aim is to check the energy balance relation in each problem which plays a very important role in the present approach of solutions of mixed boundary value problems involving Laplace equations.The main advantage of the present approach of solutions is that the results for the values of reflection and transmission coefficients obtained by using both the methods are found to satisfy the energy-balance relations associated with the respective scattering problems under consideration.The absolute values of the reflection and transmission coefficients are presented graphically against different values of the wave numbers. 展开更多
关键词 surface water waves floating elastic plates over-determined systems least squares method singular value decomposition method scattering problem reflection and transmission coefficients
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Heating frequency optimization for artificial feld-aligned scattering
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作者 Libin LV Zhensen WU +4 位作者 Qingliang LI Shuii HAO Jian DING Guanglin MA Jing CHEN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第9期52-57,共6页
In this study, we present a simulation study of artificial field-aligned irregularities(AFAI) to calculate the scattering coefficient considering a Gaussian autocorrelation function for the wave number spectrum of the... In this study, we present a simulation study of artificial field-aligned irregularities(AFAI) to calculate the scattering coefficient considering a Gaussian autocorrelation function for the wave number spectrum of the density fluctuation. By analyzing variations in the scattering coefficient under different ionospheric backgrounds, the optimal range of the heating frequency was found,which is about 0.9–1 times the critical frequency of the F2 layer. This is especially noticeable as when the heating frequency varies from 0.5 times to 0.9 times of the critical frequency, the scattering coefficient increases by 6.8–16.2 d B. These results should be useful for optimizing the heating frequency in the future artificial field-aligned scattering(AFAS) transmission applications at middle and low latitudes. 展开更多
关键词 artificial field-aligned scattering artificial field-aligned IRREGULARITIES scattering coefficient HEATING FREQUENCY
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Water Wave Scattering by an Elastic Thin Vertical Plate Submerged in Finite Depth Water
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作者 Rumpa Chakraborty B. N. Mandal 《Journal of Marine Science and Application》 2013年第4期393-399,共7页
The problem of water wave scattering by a thin vertical elastic plate submerged in uniform finite depth water is investigated here.The boundary condition on the elastic plate is derived from the Bernoulli-Euler equati... The problem of water wave scattering by a thin vertical elastic plate submerged in uniform finite depth water is investigated here.The boundary condition on the elastic plate is derived from the Bernoulli-Euler equation of motion satisfied by the plate.Using the Green’s function technique,from this boundary condition,the normal velocity of the plate is expressed in terms of the difference between the velocity potentials(unknown)across the plate.The two ends of the plate are either clamped or free.The reflection and transmission coefficients are obtained in terms of the integrals’involving combinations of the unknown velocity potential on the two sides of the plate,which satisfy three simultaneous integral equations and are solved numerically.These coefficients are computed numerically for various values of different parameters and depicted graphically against the wave number in a number of figures. 展开更多
关键词 THIN vertical ELASTIC plate uniform finite depth WATER wave scattering reflection and transmission coefficients
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Scattering of Oblique Surface Water Waves by Thin Vertical Barrier Over Undulating Bed Topography
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作者 A. Choudhary S. C. Martha 《Journal of Marine Science and Application》 CSCD 2017年第2期190-198,共9页
The present study deals with the scattering of oblique surface water waves by small undulation on the bottom in the presence of a thin vertical barrier. Here, three different configurations of vertical barriers are in... The present study deals with the scattering of oblique surface water waves by small undulation on the bottom in the presence of a thin vertical barrier. Here, three different configurations of vertical barriers are investigated. Perturbation analysis is employed to determine the physical quantities, namely, the reflection and transmission coefficients. In this analysis, many different Boundary Value Problems (BVPs) are obtained out of which the first two bvps are considered. The zeroth order bvp is solved with the aid of eigenfunction expansion method. The first order reflection and transmission coefficients are derived in terms of the integrals by the method of the Green's integral theorem. The variation of these coefficients is plotted and analyzed for different physical parameters. Furthermore, the energy balance relation, an important relation in the study of water wave scattering, is derived and checked for assuring the correctness of the numerical results for the present problem. 展开更多
关键词 OBLIQUE wave scattering bottom UNDULATION VERTICAL BARRIER EIGENFUNCTION expansion Green’s integral theorem reflection and transmission coefficients
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The EM Scattering from One-Dimensionally Lossy Fractal Surfaces
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作者 Gao Huotao Lu Shu +1 位作者 Xu Penggen Wu Zhengxian 《Wuhan University Journal of Natural Sciences》 CAS 1998年第3期78-82,共5页
The EM scattering from rough surface has been investigated in the past years.Periodic and random models are often used in modeling the rough surface.Recently,the fractal geometry is rapidly improved.It provides a new ... The EM scattering from rough surface has been investigated in the past years.Periodic and random models are often used in modeling the rough surface.Recently,the fractal geometry is rapidly improved.It provides a new way to model the rough surface whose characteristics are long range order and short range disorder.In this paper,A fractal function is used to model the rough surface.A scattering coefficient for calculating the angular distribution and the amount of energy in the spectrally scattering field to the fractal characteristics of the surfaces by finding their analytical expressions is derived by using the Kirchhoff solution.In the end,we calculate some scattering patterns. 展开更多
关键词 rough surface fractal function scattering coefficient Kirchhoff solution
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