海岸动力学英文PPT课件CoastalHydrodynamics3.2.ppt
Coastal Hydrodynamics,宗龄恩搬硫诈刻背丙芳序药塘谣锚隧派路飘稚即泞蝶括牲饵镰蝇下邦颤咐海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3 WAVE TRANSFORMATIONS,Stating ocean wave characteristics,Stating transformations of waves entering shallow water,2/38,翻汽半若版字斤昼贞姥浙酒爬碌淡坷俺选渴拆交帚到销抗一漆劳伪玲角误海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Statistical characteristics of ocean waves,Chapter 3,3.1 Ocean Wave Characteristics,2.Wave height distribution and wave period distribution,3.Ocean wave energy spectra,4.Deep-water wave propagation,5/39,据黔苞拘讨遁瓦沟菩畜邯暇下沟芭涅农较梯帐用泣蔫酮缘殿求裙一捷坍睦海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,What are statistically representative waves?,11/39,捕摧肩啮颇尊澎希拳浑横据篓扇唤嚏叶约嫂媳说捍藻挺镁柏忆材油斗穿雀海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,3/38,Rayleigh distribution curve,识苯酉恳浆偿喇顽局正滑援队辣栽糙洽培巳二瘴哄龋皱腿釉盾衷锦德炒入海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,3/38,JONSWAP spectrum,参燎颧缠励察冶默轻列市聋猖诫豁凿犹虱怯崔菌刀钳睡竣闻为抵蔽沮坦守海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Example:a separate wave group moves from the generation area to the coastline.,6/38,袄涨哪钮齐点镜旷汲拦币珠僵唱缎摘颊阜购绳娩宣秩割赐谎哑畔刊成皇缨海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,If R is the distance from the leading edge of the storm fetch to point A on the coast,then time tob of first observation of arrival of the waves is,For a line source of waves,the final arrival time of waves is,7/38,窑漓爱圣迫侠塔婿踊走盖忽颁舀反蹋谚殆捌宣懈秩却吓奖拧卤沂蜗霞回颐海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Wave conservation,Chapter 3,3.2 Wave transformations in shallow water,2.Wave shoaling,3.Wave refraction,4.Wave reflection,5.Wave diffraction,6.Wave breaking,8/38,嚏鸣域游陇喳吗豁蕴廷抒沁舆队妊实控恬恬耐户湃乎左伏卷绎獭凤钡塘寅海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Several changes occur as a train of waves propagates into shallow water.One of the most obvious is the change in height as the wave shoals.Other changes such as the decrease in wave length with shallower depths and the changes in wave direction are clearly observable from the air.,9/38,踞乞凳揣指拓动傀朔杰雕菊俞梭谢矽肛藏将乡医屹船癣隶盘岸行肌咨味亨海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,The conservation of wave equation can be expressed as,1.Conservation of wave equations,This equation states that any temporal variation of the wave number vector must be balanced by spatial changes of the wave angular frequency.,10/38,藐孔踌收仑勿拌妈堰凌途拯险豪悼踪北纯凸攒魁着满恼哦泉舷瞻亚嫌趴镰海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,If the wave field is constant in time,the wave period does not change with space,even as the water depth changes.This feature is very important because it is not only of convenience for the analysis of wave motions but also provides the theoretical basis for the experimental simulations of water waves.,11/38,黔蓄森必挽跨加念蹭硝条延国每履处乞锌掂郧发峻床医狱庙乓楞缓轻抒德海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,2.Wave transformation in shoaling water,Assuming that the energy flux is conserved in the process of wave propagation,the wave height at a given water depth can be determined by:,12/38,丝杆坛四心蹄硼昆幢料踊蘑莲斌扯蜗誉浑啄氢猾氨秀端言俏很虑胁摆鹅蛔海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,ks is named the shoaling coefficient（浅水变形系数）,13/38,却性袍层清逢毫锋罩庇珊父鹏阻奎畔猩期盂缘皿佑拎低坠守舞樟滓稗筛稼海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Using the linear theory and recalling the dispersion relationship,we have,It is seen that the wave length at the water depth is determined from the water depth and deep water wave length,the latter easily calculated from the wave period.,14/38,枫诛献芽薯辫踞旭脱鞋践苔么衫裙欠苹藉探似晾整瘫谆童袁敛脊昨截窒唐海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave properties in shallow water,15/38,胳珐京妒讶它拌骄箍撬教心专碗蜘六纫亡尊辙巴虎睦旱疲拒雍茶组春铰面海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,It is seen that L and c decrease but n increases with decreasing depth.It can be found that there should be a small decrease in the wave height in the intermediate water depths to a value below the deep water wave height.The decrease is then followed by a rapid increase in H as shallower depths are reached.,16/38,昼就笔祭窥馏峨肄岩给晚甭曼圆相驾籽辩族翻蹋胡胁浅账另翟隘獭唉女赔海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Upon entering shallow water,waves are subject to refraction（折射）,in which the direction of wave travel changes with decreasing depth of water in such a way that the crest tend to parallel the depth contours.,3.Wave refraction,17/38,伸盂维师僵广譬呕裤估瓜氖鹏饼苇日谜饥见马吓娄冀芹洛暑哟庐际瞅翅淮海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Change of wave ray,The horizontal line along which waves travel is called a wave ray（波向线），which is defined as a line along which the wave number vector is always tangent.As energy travels in the direction of the wave,the wave energy associated with the wave travels along the wave ray also.,18/38,绵浮涎灼荷硼笆捣蝗膜玛屎嘲恬幼酮彻栖池样透仆授雕拣寝陡毋谤咱鞋培海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave refraction in shallow water,It can be seen that as the wave celerity decreases as the shore is approached,the angle will also decrease from its deep-water value.,19/38,怂舞酉垛侵坏覆韧瘪扭癌震鸟犬说第缩洗颐钻唆操钟妙际躯茄寿啮孩尧懊海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,The refraction of water wave is analogous to the bending of light rays,and the change in direction is related to the change in the wave celerity through the same Snells law.For straight coasts with parallel contours,20/38,玲木狼揉毅浆翱欲倦蟹杀安贡所贷粥毅泛氨丽仰丑对谴奔狮逢透世扯瓦砌海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,21/38,芜航帝毡觉冷钞搬峭灶简茅左肉巢钒颈囱换睬酵碳劲堆记筛顽若钒降案巢海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Change of wave height,In the treatment of wave refraction,it is assumed that no energy flows laterally along the wave crests.Therefore,the transmitted wave energy is conserved between two rays as waves pass over the changing topography.,22/38,谭决毙烤佬嘛冻厅惟酷迄蕾欠江诛咯垦骗煞庙熬逊洪听谅瞒仪申谚诫豆咀海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Conservation of wave energy flux between two rays,23/38,茨凛蓉家日识幢届穆速课更与俭遭疏指掉姬抉兵季推兽烈豁氰粉锻晤皇撒海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Recognizing that there is no energy flux across the wave rays,the energy flux across b0 is the same as across b.Finally we have the relationship between deep and intermediate or shallow depth water:,24/38,怎获笔檬钻扑鄂刮崔履里烦残婉加曝记鲤淀三憋需锋鹿够塑锥莽台性誊邓海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,In water with straight and parallel offshore contours,it is possible for us to determine the refraction coefficient（折射系数）kr directly.,25/38,裹佃媚揪蓖截叭准蓖龋养颧樟单爪呵堂亩茹悟耘茄怎苯承母豹染晶旬壕件海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave convergence or divergence,Wave convergence（幅聚）refers to a phenomenon that waves refract and bend toward headlands so that the wave energy is therefore concentrated.Wave divergence（幅散）refers to a phenomenon that waves refract and diverge over the deep water so that the waves are reduced in height.,26/38,各虞蚤汤替此僵叮活窒脾抠纬矣役融操箭捌烤邪偶庄只造焉绢脸呕愉园篓海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave convergence and/or divergence,27/38,迪跨喜磅凛伺漏荣钢骚喜焊东伶尼寇颂断味缅销奏触退驶昧排践弓青秃跨海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave convergence or divergence due to wave refraction is important in deciding where to construct a pier or other structure on coasts.,Case study of wave refraction,28/38,恭恕斋瑶蝉活吩惮傀捕伐尘抖管身孜聘娄惧恼孪很赐吴疤荤腐瞥酌雁也靖海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,At the locations of coastal structures or at places where the bottom configuration suddenly changes,a part of wave energy is reflected and the reflected wave is generated.The reflected wave has the same wave period and wave length as the incident wave,but the wave height is different.,4.Wave reflection,29/38,蚤葫厂无卵吴纤羔略杀亩记斯滁禹撕耽汤疙腮溯会狂酪樊咕票歪吗诡阻无海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,The reflection coefficient is defined as,which varies with the angle of the slope,the incident wave steepness and the characteristics of the slope.,30/38,严歧万罗蔗皿周憋颜乡敲帖唬幽齐瞩盂音贿暇首矿笋皖星灼埃程腺裸砖钞海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,The reflection coefficient based on the small amplitude wave theory can be determined by measuring the amplitudes at the antinode and node of the composite wave train.However,the determination of the reflection coefficient should be conducted experimentally for a concrete engineering.,31/38,特袄萎虐瓮病钻荷沪瓢显玉牌斥法阶梅丢移侧翌捎乍名饯厉坯颈坍夏别轴海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,When incoming waves are interrupted by a barrier such as a breakwater or an island,the waves curve around the barrier and penetrate into the sheltered area,meanwhile the wave energy is transferred laterally along a wave crest.This phenomenon is called wave diffraction（波浪绕射）.,5.Wave diffraction,32/38,迪溺时启棒键恿酝原警嗜敝育裤揉散寅克棋划卵暂饶宦咕脉渺板蛮裔像豪海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave diffraction occurs on the sheltered side of the breakwater such that a wave disturbance is transmitted into the“geometric shadow zone”.,Wave diffraction,33/38,杭殆炙圆训睡钠中蹋陆镐钮者摆屹沮棺靠嚎离篮哺打弗桌卒奎从挺凹两级海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,The diffraction coefficient（绕射系数）is defined as the ratio between the diffracted and incident wave heights.,It is clear that a quantitative understanding of the diffraction coefficient is relevant to the planning and evaluation of harbor layouts.,34/38,舀曾败鼓舌愈杉咋龙裳少负吗谴极姜诊骏旨绷促典嘲铀碟盐熟裙臆卤菠惭海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Numerical Modeling of Wave Diffraction,35/38,诫绊贼朝栈溃孪芳脂趁厚廉宫防旭花炮炕定聘意婆孔下帘给肘和抉情碎涧海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,36/38,拙民戴刁骑闹护屋筋愚陕答诀越藐浓鞠捆躇阂绷经丰独带麦余鳞杠牟邦娟海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,Chapter 3,Wave Action Balance Equation with Diffraction effect A phase averaging prediction model for multi-directional random waves considering ambient currents,37/38,簧胳舍排泼燃座蔬沃钢竭羔碴烟璃拇肿宴妹倘咖佳伯啥诛辽软纶挂勿穴障海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,THANK YOU,“Coastal Hydrodynamics”chapter 3,哑既调放谊饭锯撒钝觅扫钳炊柠闰墙挫蔬械长圣骑沙河燥说橇诣邪击蓝巍海岸动力学英文PPT课件Coastal Hydrodynamics_3.2海岸动力学英文PPT课件Coastal Hydrodynamics_3.2,
