• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Numerical Simulation of Ship Icebreaking in Level Ice based on Nonlinear Finite Element Method

    2016-05-16 02:41:56WANGJinweiZOUZojin
    船舶力學(xué) 2016年12期
    關(guān)鍵詞:冰體冰區(qū)破冰船

    WANG Jin-wei,ZOU Zo-jin,b

    (a.School of Naval Architecture,Ocean and Civil Engineering;b.State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

    Numerical Simulation of Ship Icebreaking in Level Ice based on Nonlinear Finite Element Method

    WANG Jian-weia,ZOU Zao-jiana,b

    (a.School of Naval Architecture,Ocean and Civil Engineering;b.State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

    Numerical simulation of an icebreaker advancing in level ice is carried out by using the nonlinear finite element method.An ice material model is verified by comparing the simulation results with experimental data.Using the ice material model,the dynamic response of the ship during icebreaking in level ice of different thicknesses at different speeds is numerically studied.The deformations of level ice,the magnitudes of ice force,the changes of ice deformation energy and kinetic energy during the icebreaking process are presented,and the influences of the ship speed and level ice thickness on the icebreaking resistance are analyzed.The results have a certain reference value for analyzing the dynamic response of an icebreaker in level ice.

    icebreaker;level ice;icebreaking resistance;nonlinear FEM; numerical simulation

    0 Introduction

    Due to the climate change,the melting speed of ice in Arctic region has been accelerating,which makes the marine transportation in Arctic region possible.In these waters,merchant ships need to clear channel with the help of icebreakers to ensure a successful navigation. Besides,since the global economy is developing rapidly,the resource requirements have been increasing.As the land resources being exhausted,the exploitation of energy in ocean and polar becomes urgent,and the scientific investigation of polar energy is only possible by means of icebreaking.Nowadays,a new generation of icebreaker is under researching and developing all over the world;to accurately predict the dynamic performance of an icebreaker in level ice is of particular importance for icebreaker design,and relevant researches have a practical significance.

    In recent years,some researchers have studied icebreaking resistance of polar ships.Wang et al[1]used two commercial finite element codes(ANSYS and LS-DYNA)to present numerical results of resistance prediction for an icebreaker in level ice.Park et al[2]applied three methods including empirical analysis,numerical analysis and physical model experiments toobtain icebreaking resistance of three ore carriers that have different hull forms under the same ship speed and ice thickness.Considering the coupling between continuous ice forces and ship motions,Su et al[3]used a numerical method to simulate ship maneuvers in level ice and solved the equation of three degree-of-freedom rigid body surge,sway and yaw motions.Some other researchers have studied the issues related to structural response of ship-ice collision.Wang et al[4]developed a collision model for nonlinear dynamic finite element analysis on a LNG ship and crushable ice using commercial code DYTRAN.Lee et al[5]established the finite element model of Arctic LNG carriers and predicted impact loadings from ship and iceberg collision. Liu[6]studied the numerical model of ice materials and applied it to dynamic analysis of shipiceberg collision.Kim et al[7]used finite element model and scale model test to investigate the resistance performance of an icebreaking cargo vessel in pack ice conditions.Yang et al[8]adopted the method of fluid-structure interaction and established the nonlinear finite element model of collision between ship and ocean platform by taking sea ice as medium.They simulated the collision process numerically,compared the results of collision under conditions with and without sea ice medium and analyzed the influence of the range of sea ice on platform. Zhang et al[9-10]performed a numerical simulation of ship-ice collision by using a nonlinear finite element method.

    This paper conducts a numerical simulation study on the dynamic response of an icebreaker in level ice by using the commercial software LS-DYNA based on the nonlinear finite element method.The reliability of the proposed ice material model is firstly verified;the 3D finite element models of ship and level ice are established.The deformation of level ice,the ice force and the ice deformation energy and kinetic energy during the icebreaking process are predicted by numerical simulation,and the influences of ship speed and ice thickness on the icebreaking resistance are analyzed.

    1 Mathematical model

    In the finite element method,the motion equation of ship in level ice can be described as

    where M is the mass matrix,C is the damping matrix,K is the stiffness matrix,x is the displacement vector,and Fextis the external load vector.

    It is assumed that the acceleration remains the same in one time step.The explicit central difference method is used to discretize the motion equation,and the solving formula can be derived as

    2 Numerical modeling of ice material

    Tab.1 Ice model characteristics

    In order to verify the ice material,the reaction generated from the extrusion on ice cone by steel plate is calculated.The finite element model is shown in Fig.1.The fixed boundary condition(fixed B.C.)is applied at ice cone bottom to implement the conditions attached to the testing machine.A steel plate attached on the top of the testing machine is moving downwards at a specified velocity v.Two body contact simulation is performed.The material property of the steel plate is taken as a rigid body,because the plate is thick enough to be considered as rigid.The characteristics of the steel material model are shown in Tab.2.

    Fig.1 FE model of ice cone and steel plate

    Tab.2 Steel material model characteristics

    The numerical simulation model developed in this study is verified by comparing the results of numerical simulation with the test results of Ref.[11].An ice cone with 10cm diameter and 120°coning angle is chosen for the test.The main focus of developing a numerical simulation model is to create a model that can be directly applied to a diverse condition such asdifferent strain-rate or ice size.In other words,the aim is to create a numerical simulation model that can be used in multiple conditions without any modification of ice material properties or simulation conditions.The application of the ice material model under different strainrate conditions are investigated firstly,setting steel plate speed v=1 mm/s and 100 mm/s respectively.The comparison of the ice force-displacement curves at different steel plate speeds is shown in Fig.2.

    Fig.2 Comparison of ice force-displacement curves at different steel plate speeds,case 1

    From Fig.2 it can be seen that the numerical and experimental results agree well to a certain extent and the error at low speed is smaller than that at high speed.No matter at low speed or at high speed,the calculated results exhibit the correct growth trend of ice force with displacement.The ice force fluctuates at some displacement,because that as the steel plate is pressing the ice body,the phenomenon of broken occurs,causing immediately the drastic changes of ice force.

    In order to verify the reliability of the ice material model further,it is applied to a larger ice cone with 25 cm diameter and 130°coning angle.The numerical and experimental results of ice force-displacement curves at the steel plate speed 1 mm/s and 100 mm/s are compared in Fig.3.From this figure it can be seen that the growth trends of the calculated and experimental ice forces agree well,and they both show the fluctuation generated from the ice body’s fracture.The higher the steel plate speed is,the larger the fluctuation amplitude is.These results indicate that the ice material model selected in this paper can be used for numerical sim-ulation of the collisions between ship and ice.

    Fig.3 Comparison of ice force-displacement curves at different steel plate speeds,case 2

    3 Numerical simulation of ship in level ice

    3.1 3D finite element model of an icebreaker

    An icebreaker is selected in this paper,whose particulars are listed in Tab.3.

    For the real ship,high-strength steel is used in ship bow,whose deformation can be ignored during the icebreaking process.Therefore,in order to simplify the model,the hull plate is regarded as rigid and the internal structure is ignored in the numerical simulation.For the motion states of the ship, regardless of the influence on ship motion in icebreaking process,the ship is set to move forward at a constant speed,and the other five degrees of freedom of motionare constrained.

    3.2 3D finite element model of level ice

    During the icebreaking process,the mechanical properties of level ice are internal factors which affect fracture of level ice and are the basis of study on icebreaking resistance. During the process of ship-ice collision,ice will be broken when the ice stress reaches a certain value.The interaction between ice and ship will show different damage forms,which immediately influence the ice load on ship.In general,there are four forms of ice failure,including crushing failure,buckling failure,shear failure and bending failure[12].

    For establishing 3D finite element model of level ice,solid element is used considering the ice thickness and generation as well as extension of cracks.There are two methods to simulate the generation and extension of cracks.One is that cracks are generated in the structure by element failure;the other one is that cracks are generated by defining the failure of constraint nodes.The first method requires that there is a dense grid in cracks of the model;the shortcomings of the second method is that the process of establishing the model is relatively complex[13].In this paper,the first method is chosen to establish the model.When the stress and strain of the finite element model exceed a certain value,the element will be of failure, and the element will be deleted from the model.Cracks occur when numerous elements are deleted from a path.That is why the grids of level ice should be divided densely.In this paper,the size of the solid element is 125 mm×125 mm×125 mm.

    The icebreaking resistance when the ship sails in infinite level ice is studied.Different from floating ice,infinite level ice can be regarded as fixed.Limited by the conditions of numerical simulation,size of the level ice cannot be established infinitely.In this paper,the length of the level ice along the longitudinal direction(X-direction)is taken as 40 m,and the length perpendicular to the longitudinal direction(Y-direction)is 80 m.The boundary that collides with the ship is the free end.The influence of the collision area on far-field of the level ice is so small that it can be neglected;hence the far-field boundary is simplified as rigid fixed.

    Tab.3 Ship characteristics

    3.3 Application of fluid-structure interaction

    In the icebreaking process,the buoyancy and gravity of ice need to be considered.Gravity is loaded through body force and the gravitational acceleration is 9.81 N/kg.The load of buoyancy is realized by utilizing fluid-structure interaction.

    There are three basic algorithms about 3D finite element in LS-DYNA.They are Lagrange, Euler and ALE(Arbitrary Lagrange-Euler)formulations.Solid structures usually adopt Lagrange formulation,whose element is attached to the material and is deformed with the change of the structure’s form.As for fluid-structure interaction,the flow of material may result in serious deform of finite element.Thus it may cause the difficulty of numerical simulation and end the operation of the program.Euler formulation can be understood as the fact that two layers of mesh overlap with each other.One layer is fixed in the space and the other one is attached to the material;it flows in the space grid with the material and is achieved through the following two steps:The material grid firstly performs a Lagrange step,and then the state variables of Lagrange elements are reflected in or transported to the fixed space grid.This grid is always fixed and indeformable,just as material flowing in the grid.Like the Euler formulation,in ALE the space grid can be interpreted as two layers of grids overlapping.But it can freely flow in the space.ALE and Euler formulations can overcome the difficulty of numerical simulation caused by serious deforms of element and implement the dynamic analysis of fluid-structure interaction.

    This paper simulates the dynamic process of fluid-structure interaction with LS-DYNA and ALE formulation.Through the load of gravity on water and air,pressure gradient is generated in the vertical direction and the buoyancy on the ice is simulated.

    Fluid materials in the numerical model include water and air.In the finite element model,these two materials have the same nodes.The length and width of water and air are the same as those of level ice.However,the height of water is 4 times of the draft and the height of air is 1.5 times of the draft.

    Both of water and air adopt null material model to simulate the materials having fluid behaviors and linear polynomial state equation,whose pressure is calculated as

    where ci(i=0,1,2,…6)are the coefficients;E is the internal energy of unit volume, V is the relative volume.

    3.4 Ship-ice contact model

    There are a lot of contact models in LS-DYNA,including node-to-surface contact,surface-to-surface contact and single-surface contact.Considering the failure of ice material and the penetration phenomenon generated during the collision,this paper adopts eroding-surfaceto-surface contact model.This model is very useful and is generally applied in the contacts of various shapes and large contact areas.

    4 Results and analysis of numerical simulation

    As shown in Fig.4,the water plane of the level ice is consistent with that of the ship.In the simulation,the ship speed is 2 m/s.The distance between the ship and the level ice is 0.1 m before simulation and simulation time is 8.0 s.

    Fig.4 FE model of ship icebreaking in level ice

    4.1 Results of numerical simulation of icebreaking process

    The deformations of the level ice at 2.0 s,4.0 s,6.0 s and 8.0 s are shown in Fig.5.It can be seen in Fig.5 that the deformation mainly occurs in the area of ice contacting and colliding with the icebreaker.After colliding with the ship,the ice failure occurs when the failure pressure is reached.The cracks are generated by elements deleted for failure.During the icebreaking process,because of the brittleness of the ice material,some ices are separated from the level ice and flow in the water.

    Fig.5 Deformation of the level ice

    Fig.6 Time history of ice force on ship in Y direction

    Fig.7 Time history of ice force on ship in Z direction

    The time histories of ice force on the ship in Y direction and Z direction are shown in Fig.6 and Fig.7,respectively.From these figures it can be seen that during the whole period, the ice force presents highly nonlinear characteristics and changes violently with time,with a general rising trend.From the analysis of the time histories of ice force in Fig.6 and Fig.7 and the deformation of level ice in Fig.5,it is known that the unloading phenomenon is generated by ice failure as the ship moves in the level ice.

    4.2 Influence of ship speed

    In order to study the influence of ship speed on the icebreaking resistance,numerical simulation is carried out for the ship sailing in the level ice of thickness 0.5 m at the speed 2 m/s,3 m/s and 4 m/s.

    The time histories of the icebreaking resistance at different ship speeds are shown in Fig.8.It can be seen that the ship speed has a significant influence on the icebreaking resistance and the amplitude and peak value of icebreaking resistance increase with the ship speed. The common point of the time histories at different ship speeds is that as the icebreaking resistance rises,it will suddenly drop.It shows an unloading phenomenon during the icebreaking process because of the ice element failure.

    Fig.8 Time histories of the icebreaking resistance at different ship speeds

    The time histories of the level ice deformation energy and kinetic energy at different ship speeds are shown in Fig.9.It can be seen that the level ice deformation energy and kinetic energy increase with the ship speed.

    Fig.9 Time histories of level ice deformation energy and kinetic energy at different ship speeds

    4.3 Influence of ice thickness

    In order to study the influence of ice thickness on the icebreaking resistance,numerical simulation is carried out for the ship sailing at the speed of 2 m/s in the level ice of thickness 0.25 m,0.50 m,0.75 m.The time histories of icebreaking resistance under different ice thicknesses are shown in Fig.10.It can be seen that the peak value of icebreaking resistance increases with the ice thickness.Besides,the time histories show the different degrees of fluctuation for the level ice with different thicknesses.It also shows the unloading phenomenon in icebreaking resistance during the icebreaking process because of the ice element failure.

    Fig.10 Time histories of the icebreaking resistance under different ice thicknesses

    The time histories of level ice deformation energy and kinetic energy under different ice thicknesses are shown in Fig.11.It can be seen that the level ice deformation energy and kinetic energy increase with the ice thicknesses.

    Fig.11 Time histories of level ice deformation energy and kinetic energy under different ice thicknesses

    5 Conclusions

    This paper carries out a numerical simulation study on the dynamic response of an icebreaker during icebreaking process in level ice by using finite element method.The ice material model used in the numerical simulation is firstly verified.Systematic numerical simulationis are then carried out for the icebreaker at different forward speeds in the level ice of different thicknesses.The following conclusions can be drawn from this study:

    (1)The ice material model proposed in this paper is used in numerical simulation underdifferent conditions.The validity of the model is verified by comparing the simulation results with those of experiment.It is shown that the material model can be applied in numerical simulation of icebreaking process;

    (2)Keeping the ice thickness unchanged,the peak values of ice force,level ice deformation energy and kinetic energy increase with ship speed;

    (3)Keeping the ship speed unchanged,the peak values of ice force,level ice deformation energy and kinetic energy increase with ice thicknesses;

    The results of this study can provide a certain reference for the design of icebreakers to be served as icebreaking in level ice.

    [1]Wang J,Derradji-Aouat A.Numerical prediction for resistance of Canadian icebreaker CCGS Terry Fox in level ice[C]// ICSOT2009,International Conference on Ship and Offshore Technology.Busan,Korea,2009:9-15.

    [2]Park K D,Chung Y K,Jang Y S,et al.Development of hull forms for a 190,000 DWT icebreaking ore carrier[C]// OMAE2011,30th International Conference on Ocean,Offshore and Arctic Engineering.Rotterdam,the Netherlands, 2011,1:949-955.

    [3]Su B,Riska K,Moan T.A numerical method for the prediction of ship performance in level ice[J].Cold Regions Science and Technology,2010,60(3):177-188.

    [4]Wang B,Yu H C,Basu R.Ship and ice collision modeling and strength evaluation of LNG ship structure[C]//OMAE2008, 27th International Conference on Offshore Mechanics and Arctic Engineering.Estoril,Portugal,2008,3:911-918.

    [5]Lee S G,Lee J S,Baek Y H,et al.Structural safety assessment in membrane-type CCS in LNGC under iceberg collisions [C]//ICSOT2009,International Conference on Ship and Offshore Technology.Busan,Korea,2009:69-81.

    [6]Liu Z.Analytical and numerical analysis of iceberg collisions with ship structures[D].Trondheim:Norwegian University of Science and Technology,2011.

    [7]Kim M C,Lee S K,Lee W J,et al.Numerical and experimental investigation of the resistance performance of an icebreaking cargo vessel in pack ice conditions[J].International Journal of Naval Architecture and Ocean Engineering,2013, 5(1):116-131.

    [8]Yang L,Ma J.Numerical simulation analysis for the collision between offshore platform under the sea ice medium[J].China Offshore Platform,2008,23(2):29-33.(in Chinese)

    [9]Zhang J,Wan Z Q,Chen C.Research on structure dynamic response of bulbous bow in ship-ice collision load[J].Journal of Ship Mechanics,2014,18(1):106-114.(in Chinese)

    [10]Zhang J,Zhang M R,Wan Z Q,et al.Research on ice material model applied in numerical simulation of ship structure response under iceberg Collision[J].Shipbuilding of China,2013(4):100-108.(in Chinese)

    [11]Kim H.Simulation of compressive‘cone-shaped’ice specimen experiments using LS-DYNA[C]//13th International LSDYNA Users Conference.Detroit,America,2014.

    [12]Wei W D,Ning J G.Critical load between sea ice and sea structure[J].Journal of Glaciology and Geocryology,2003,25 (3):351-354.

    [13]Bai Z J.Theoretical basis and example analysis of LS-DYNA3D[M].Beijing:Science Press,2005.(in Chinese)

    基于非線性有限元法的船舶冰區(qū)破冰數(shù)值模擬

    王健偉a,鄒早建a,b

    (上海交通大學(xué)a.船舶海洋與建筑工程學(xué)院;b.海洋工程國家重點實驗室,上海200240)

    應(yīng)用非線性有限元法進行了破冰船冰區(qū)破冰數(shù)值模擬。通過比較數(shù)值模擬結(jié)果和試驗結(jié)果,對冰體材料模型進行了驗證;采用該冰體材料模型,對破冰船以不同航速在不同厚度的層冰中破冰航行時的動態(tài)響應(yīng)進行了數(shù)值研究,給出了破冰過程中層冰的變形、冰力的大小以及冰的變形能和動能變化,分析了船速、冰層厚度對破冰阻力的影響。該研究結(jié)果對分析破冰船在層冰中破冰時的動態(tài)響應(yīng)特性具有一定的參考價值。

    破冰船;層冰;破冰阻力;非線性有限元法;數(shù)值模擬

    U661.4

    A

    王健偉(1989-),男,上海交通大學(xué)碩士;鄒早建(1956-),男,上海交通大學(xué)教授,博士生導(dǎo)師。

    U661.4 < class="emphasis_bold">Document code:A

    A

    10.3969/j.issn.1007-7294.2016.12.008

    1007-7294(2016)12-1584-11

    Received date:2016-08-24

    Biography:WANG Jian-wei(1989-),male,master of Shanghai Jiao Tong University,E-mail:wangjianweime@163.com; ZOU Zao-jian(1956-),professor/tutor of Shanghai Jiao Tong University,E-mail:zjzou@sjtu.edu.cn.

    猜你喜歡
    冰體冰區(qū)破冰船
    “怪獸號”破冰船
    照亮回家的路
    我國高校首艘破冰船“中山大學(xué)極地”號成功開展冰區(qū)試航
    珠江水運(2023年3期)2023-03-04 16:28:28
    重覆冰區(qū)220kV雙回路窄基鋼管塔設(shè)計及試驗研究
    吉林電力(2022年1期)2022-11-10 09:20:48
    彈體高速侵徹冰體研究
    冰區(qū)船舶壓載艙防凍方案研究
    能源工程(2022年2期)2022-05-23 13:51:44
    高速彈體侵徹冰材料過程數(shù)值模擬研究
    世界最大破冰船
    冰體質(zhì)量和撞擊角度對船首結(jié)構(gòu)碰撞性能的影響
    基于船-水-冰耦合技術(shù)的撞擊參數(shù)對船冰碰撞性能的影響
    久久精品91无色码中文字幕| 国产亚洲精品久久久久5区| 巨乳人妻的诱惑在线观看| 久热爱精品视频在线9| 久久青草综合色| √禁漫天堂资源中文www| av片东京热男人的天堂| 亚洲精品国产精品久久久不卡| 男人舔奶头视频| 欧美绝顶高潮抽搐喷水| 国产亚洲欧美精品永久| 男女视频在线观看网站免费 | 亚洲中文日韩欧美视频| 国产亚洲欧美98| 啪啪无遮挡十八禁网站| 国产精品久久久久久亚洲av鲁大| 国内久久婷婷六月综合欲色啪| 亚洲精华国产精华精| 亚洲国产欧美日韩在线播放| 97超级碰碰碰精品色视频在线观看| 丝袜美腿诱惑在线| av在线播放免费不卡| 国产精品亚洲一级av第二区| 两性午夜刺激爽爽歪歪视频在线观看 | 美国免费a级毛片| 91大片在线观看| 精品久久久久久成人av| 精品日产1卡2卡| 老司机福利观看| 国产亚洲av嫩草精品影院| 久久久久久久午夜电影| 88av欧美| 久久99热这里只有精品18| 午夜福利18| 精品少妇一区二区三区视频日本电影| 国产熟女xx| 亚洲av成人一区二区三| 亚洲中文日韩欧美视频| 97超级碰碰碰精品色视频在线观看| 成人午夜高清在线视频 | 制服诱惑二区| 黑丝袜美女国产一区| 日韩精品免费视频一区二区三区| 国产一级毛片七仙女欲春2 | 亚洲第一欧美日韩一区二区三区| 婷婷精品国产亚洲av在线| 亚洲国产精品合色在线| 国产精品一区二区免费欧美| 午夜老司机福利片| av视频在线观看入口| 久久久久久久久久黄片| 亚洲真实伦在线观看| 日本成人三级电影网站| 中文字幕av电影在线播放| www国产在线视频色| 亚洲成人久久爱视频| 黄片大片在线免费观看| 90打野战视频偷拍视频| 88av欧美| 哪里可以看免费的av片| 亚洲熟妇熟女久久| 久久久水蜜桃国产精品网| 黄色视频不卡| 亚洲狠狠婷婷综合久久图片| 两个人免费观看高清视频| 搡老岳熟女国产| 男人舔女人的私密视频| 久久精品人妻少妇| 日本五十路高清| 亚洲成人久久性| 久热爱精品视频在线9| 一本综合久久免费| 两性午夜刺激爽爽歪歪视频在线观看 | 国产又爽黄色视频| 午夜福利欧美成人| 国产亚洲精品综合一区在线观看 | 中文字幕人妻熟女乱码| 欧美成人性av电影在线观看| а√天堂www在线а√下载| 长腿黑丝高跟| 99在线人妻在线中文字幕| 美女午夜性视频免费| 国产真人三级小视频在线观看| 美女午夜性视频免费| 国内揄拍国产精品人妻在线 | 久久久水蜜桃国产精品网| 国产成人系列免费观看| 在线观看66精品国产| 黑人巨大精品欧美一区二区mp4| 精品不卡国产一区二区三区| av免费在线观看网站| 亚洲中文日韩欧美视频| 国产在线精品亚洲第一网站| 欧美一级a爱片免费观看看 | 亚洲五月婷婷丁香| 日韩欧美免费精品| 亚洲成av片中文字幕在线观看| 国产成人系列免费观看| 精品电影一区二区在线| 777久久人妻少妇嫩草av网站| 亚洲av成人一区二区三| 黑人欧美特级aaaaaa片| 熟女少妇亚洲综合色aaa.| 性欧美人与动物交配| 一区福利在线观看| 国产精品香港三级国产av潘金莲| 婷婷六月久久综合丁香| 亚洲精品美女久久久久99蜜臀| 女性生殖器流出的白浆| 免费看美女性在线毛片视频| 90打野战视频偷拍视频| 久久天堂一区二区三区四区| 精品国产美女av久久久久小说| 麻豆成人av在线观看| 在线播放国产精品三级| 久久久久国产一级毛片高清牌| 久99久视频精品免费| 精品久久久久久久末码| 中文字幕另类日韩欧美亚洲嫩草| 欧美激情极品国产一区二区三区| 色综合站精品国产| 一区二区日韩欧美中文字幕| 国产高清激情床上av| 欧美黑人精品巨大| 亚洲av美国av| 黑丝袜美女国产一区| 久久久久国内视频| 国产真实乱freesex| 老司机午夜十八禁免费视频| 亚洲第一电影网av| 久久草成人影院| 久久久久久亚洲精品国产蜜桃av| www国产在线视频色| www.熟女人妻精品国产| 真人做人爱边吃奶动态| 91九色精品人成在线观看| 男男h啪啪无遮挡| 欧美日本视频| 曰老女人黄片| 在线观看www视频免费| 一级黄色大片毛片| 一本大道久久a久久精品| 精品国产国语对白av| 亚洲av中文字字幕乱码综合 | 国产精品一区二区精品视频观看| 天天一区二区日本电影三级| 国产亚洲精品av在线| 国产成人精品久久二区二区免费| 久久青草综合色| 我的亚洲天堂| 黄片播放在线免费| 黑人欧美特级aaaaaa片| 久久人妻av系列| 九色国产91popny在线| 黄色丝袜av网址大全| 国产伦一二天堂av在线观看| 黑人巨大精品欧美一区二区mp4| 色婷婷久久久亚洲欧美| 国产伦在线观看视频一区| 99久久99久久久精品蜜桃| 亚洲av片天天在线观看| av电影中文网址| 国产黄片美女视频| 757午夜福利合集在线观看| 麻豆成人av在线观看| 嫩草影视91久久| 久热这里只有精品99| 亚洲精品美女久久久久99蜜臀| 久久中文字幕人妻熟女| 久久精品国产亚洲av高清一级| 麻豆av在线久日| 青草久久国产| 国产真实乱freesex| 免费在线观看亚洲国产| 日韩欧美国产在线观看| 黄色毛片三级朝国网站| 丁香六月欧美| 无限看片的www在线观看| 久久婷婷成人综合色麻豆| 中文字幕人成人乱码亚洲影| www.999成人在线观看| 女生性感内裤真人,穿戴方法视频| 男女床上黄色一级片免费看| 免费高清视频大片| 变态另类丝袜制服| 欧美日韩中文字幕国产精品一区二区三区| 女生性感内裤真人,穿戴方法视频| 日本a在线网址| 啪啪无遮挡十八禁网站| 日本一区二区免费在线视频| 欧美日韩亚洲国产一区二区在线观看| 黄色毛片三级朝国网站| 国产视频一区二区在线看| 97碰自拍视频| 免费av毛片视频| 亚洲av第一区精品v没综合| 久久九九热精品免费| 亚洲成av人片免费观看| 一区二区三区精品91| 首页视频小说图片口味搜索| 国产aⅴ精品一区二区三区波| 天堂影院成人在线观看| 国产激情偷乱视频一区二区| 黄色成人免费大全| 97碰自拍视频| 日韩欧美三级三区| 国产精品,欧美在线| 国产精品一区二区三区四区久久 | 午夜亚洲福利在线播放| 免费搜索国产男女视频| 一个人观看的视频www高清免费观看 | 丰满的人妻完整版| 国产亚洲精品久久久久5区| 真人一进一出gif抽搐免费| www.精华液| 男男h啪啪无遮挡| 亚洲一区二区三区色噜噜| 久久99热这里只有精品18| 国产午夜精品久久久久久| a级毛片a级免费在线| 国产精品久久视频播放| 国产单亲对白刺激| 成熟少妇高潮喷水视频| 中文在线观看免费www的网站 | 18禁裸乳无遮挡免费网站照片 | 国产国语露脸激情在线看| 亚洲人成伊人成综合网2020| 亚洲第一电影网av| svipshipincom国产片| 50天的宝宝边吃奶边哭怎么回事| 成人精品一区二区免费| 久久精品国产综合久久久| 亚洲午夜精品一区,二区,三区| 女同久久另类99精品国产91| 老司机靠b影院| 亚洲真实伦在线观看| 欧美黑人精品巨大| 99国产精品一区二区三区| 少妇熟女aⅴ在线视频| ponron亚洲| 一a级毛片在线观看| 一个人免费在线观看的高清视频| 99国产精品一区二区蜜桃av| aaaaa片日本免费| 免费观看精品视频网站| 麻豆成人av在线观看| 国产又色又爽无遮挡免费看| 99国产综合亚洲精品| 久99久视频精品免费| 最新美女视频免费是黄的| 国产熟女xx| 妹子高潮喷水视频| av欧美777| 搡老妇女老女人老熟妇| 一进一出抽搐动态| 91老司机精品| 少妇 在线观看| 亚洲美女黄片视频| 日韩成人在线观看一区二区三区| 亚洲国产看品久久| 中国美女看黄片| 国产亚洲欧美98| 亚洲精品av麻豆狂野| 免费无遮挡裸体视频| 男女做爰动态图高潮gif福利片| 日本 欧美在线| 国产又黄又爽又无遮挡在线| 日韩中文字幕欧美一区二区| 亚洲av电影在线进入| 色综合欧美亚洲国产小说| 美女国产高潮福利片在线看| 午夜a级毛片| 久久天躁狠狠躁夜夜2o2o| www.精华液| 又紧又爽又黄一区二区| 久久精品国产清高在天天线| 久久精品91无色码中文字幕| 成年女人毛片免费观看观看9| av电影中文网址| 丁香欧美五月| 大香蕉久久成人网| 热re99久久国产66热| 日韩成人在线观看一区二区三区| 亚洲av电影在线进入| 欧美一级毛片孕妇| 午夜激情av网站| 国产精品免费一区二区三区在线| 国产精华一区二区三区| 国内精品久久久久精免费| 午夜视频精品福利| 黄频高清免费视频| 日韩欧美国产在线观看| 老汉色∧v一级毛片| 亚洲人成77777在线视频| 国内精品久久久久久久电影| 好看av亚洲va欧美ⅴa在| 国产精品久久久久久精品电影 | 久久久久久久久免费视频了| 久久香蕉精品热| 久久精品影院6| 国产精品美女特级片免费视频播放器 | 国产亚洲精品久久久久久毛片| 国产精品久久久人人做人人爽| av超薄肉色丝袜交足视频| 欧洲精品卡2卡3卡4卡5卡区| 一级a爱视频在线免费观看| 视频区欧美日本亚洲| 久久精品91无色码中文字幕| 男女那种视频在线观看| 悠悠久久av| 欧美日韩中文字幕国产精品一区二区三区| 非洲黑人性xxxx精品又粗又长| 亚洲中文日韩欧美视频| 人人妻人人澡欧美一区二区| 亚洲精品中文字幕一二三四区| 亚洲av电影不卡..在线观看| 99国产精品一区二区三区| 日韩欧美一区视频在线观看| 高清毛片免费观看视频网站| 一级毛片精品| 日韩精品青青久久久久久| 一个人免费在线观看的高清视频| 97超级碰碰碰精品色视频在线观看| 色婷婷久久久亚洲欧美| 精华霜和精华液先用哪个| 99久久无色码亚洲精品果冻| 亚洲欧洲精品一区二区精品久久久| 夜夜看夜夜爽夜夜摸| 美女高潮到喷水免费观看| 真人一进一出gif抽搐免费| 窝窝影院91人妻| 好男人电影高清在线观看| 久久久国产精品麻豆| 很黄的视频免费| 亚洲自偷自拍图片 自拍| 美女免费视频网站| 久久久久久久精品吃奶| 成人18禁在线播放| 在线观看66精品国产| 亚洲男人天堂网一区| 国产av又大| 精品久久久久久久人妻蜜臀av| 亚洲欧美日韩无卡精品| 亚洲黑人精品在线| 黄色片一级片一级黄色片| 黄色丝袜av网址大全| 不卡av一区二区三区| 老汉色∧v一级毛片| 久久99热这里只有精品18| 久久久久久国产a免费观看| 亚洲精华国产精华精| 热99re8久久精品国产| 欧美久久黑人一区二区| 搞女人的毛片| 国产精品影院久久| 长腿黑丝高跟| 国内精品久久久久久久电影| 黑人操中国人逼视频| 99re在线观看精品视频| 国产精品 国内视频| 我的亚洲天堂| 欧美又色又爽又黄视频| 最近最新中文字幕大全免费视频| 欧美国产日韩亚洲一区| 不卡一级毛片| 国产精品自产拍在线观看55亚洲| 久久久久久亚洲精品国产蜜桃av| 搞女人的毛片| 久热这里只有精品99| 午夜福利视频1000在线观看| 黑人欧美特级aaaaaa片| 久久国产乱子伦精品免费另类| 一区二区三区精品91| 9191精品国产免费久久| 一级a爱片免费观看的视频| 日韩高清综合在线| 波多野结衣巨乳人妻| 91麻豆精品激情在线观看国产| 最新在线观看一区二区三区| 亚洲电影在线观看av| 成人午夜高清在线视频 | 国产精品香港三级国产av潘金莲| 久久香蕉激情| 韩国av一区二区三区四区| 在线观看一区二区三区| 免费人成视频x8x8入口观看| 亚洲第一电影网av| 午夜两性在线视频| 国产精品九九99| 亚洲第一欧美日韩一区二区三区| 精品不卡国产一区二区三区| 久久久久久久久久黄片| 一区二区三区精品91| 我的亚洲天堂| 他把我摸到了高潮在线观看| 免费看十八禁软件| 久久久久久久久免费视频了| 欧美一区二区精品小视频在线| or卡值多少钱| 女人被狂操c到高潮| av免费在线观看网站| 十八禁网站免费在线| 欧美乱妇无乱码| 亚洲国产日韩欧美精品在线观看 | 亚洲精品在线美女| 久久精品影院6| 非洲黑人性xxxx精品又粗又长| 欧美精品啪啪一区二区三区| 免费电影在线观看免费观看| 黄色片一级片一级黄色片| 日本在线视频免费播放| 又黄又爽又免费观看的视频| 欧美黑人精品巨大| 黄片大片在线免费观看| 人人妻人人看人人澡| 国产真人三级小视频在线观看| 亚洲五月天丁香| 人人澡人人妻人| 波多野结衣高清无吗| 亚洲一码二码三码区别大吗| 亚洲欧洲精品一区二区精品久久久| 亚洲成人免费电影在线观看| 久久久久久大精品| 精品日产1卡2卡| 国产视频一区二区在线看| 久久久久久大精品| 黄色丝袜av网址大全| 久久精品人妻少妇| 男女视频在线观看网站免费 | 亚洲第一电影网av| 好男人电影高清在线观看| 夜夜爽天天搞| 国产激情欧美一区二区| 精品国产一区二区三区四区第35| 欧美成狂野欧美在线观看| 熟妇人妻久久中文字幕3abv| 久久久久久久久久黄片| 国产免费av片在线观看野外av| 精品久久久久久成人av| 99国产精品99久久久久| 国产高清激情床上av| 欧美日韩福利视频一区二区| 女性被躁到高潮视频| 亚洲av成人av| 国产av一区在线观看免费| 亚洲精品国产区一区二| 成在线人永久免费视频| 日本三级黄在线观看| 久久久久久九九精品二区国产 | 亚洲精品美女久久av网站| 欧美日韩一级在线毛片| 久久久久免费精品人妻一区二区 | 天天添夜夜摸| 亚洲精品国产一区二区精华液| 国产午夜福利久久久久久| 午夜福利一区二区在线看| 国产精品自产拍在线观看55亚洲| 午夜精品在线福利| 国产高清videossex| 日韩精品中文字幕看吧| 国产av在哪里看| 国产精品日韩av在线免费观看| 久久精品成人免费网站| 国产亚洲欧美精品永久| 亚洲av五月六月丁香网| 国产一区在线观看成人免费| 香蕉丝袜av| 精品无人区乱码1区二区| 欧美久久黑人一区二区| 动漫黄色视频在线观看| 免费av毛片视频| 69av精品久久久久久| 桃色一区二区三区在线观看| 免费一级毛片在线播放高清视频| 少妇 在线观看| 午夜a级毛片| 最近最新免费中文字幕在线| 99国产精品99久久久久| 香蕉av资源在线| 婷婷丁香在线五月| 成人av一区二区三区在线看| 亚洲黑人精品在线| 美国免费a级毛片| 亚洲精品美女久久av网站| 亚洲第一电影网av| 午夜影院日韩av| 可以在线观看的亚洲视频| 亚洲午夜精品一区,二区,三区| 长腿黑丝高跟| 校园春色视频在线观看| 男人舔女人的私密视频| 中国美女看黄片| 欧美乱色亚洲激情| 19禁男女啪啪无遮挡网站| 国产片内射在线| 成人三级黄色视频| 午夜老司机福利片| 熟女电影av网| 欧美日韩亚洲综合一区二区三区_| 亚洲 欧美一区二区三区| 一进一出好大好爽视频| 欧美黄色淫秽网站| 亚洲一区二区三区色噜噜| 国产精品久久久久久人妻精品电影| 国产激情偷乱视频一区二区| 在线免费观看的www视频| 婷婷丁香在线五月| 久久欧美精品欧美久久欧美| 香蕉国产在线看| 又紧又爽又黄一区二区| 日本a在线网址| 国产亚洲精品av在线| 国产一区二区在线av高清观看| 成人18禁高潮啪啪吃奶动态图| 波多野结衣av一区二区av| bbb黄色大片| 亚洲 欧美 日韩 在线 免费| 国产精品久久久久久人妻精品电影| 欧美日本视频| 欧美日韩中文字幕国产精品一区二区三区| 国产单亲对白刺激| 亚洲国产高清在线一区二区三 | 日本a在线网址| 在线国产一区二区在线| 黄色女人牲交| 亚洲成a人片在线一区二区| 国产精品一区二区精品视频观看| 国产黄a三级三级三级人| 中文字幕最新亚洲高清| 亚洲精品在线观看二区| 这个男人来自地球电影免费观看| 亚洲国产日韩欧美精品在线观看 | 亚洲国产看品久久| 国产97色在线日韩免费| 日本免费一区二区三区高清不卡| 欧美成狂野欧美在线观看| 日本成人三级电影网站| 99国产精品一区二区蜜桃av| 好看av亚洲va欧美ⅴa在| videosex国产| 亚洲在线自拍视频| 国产91精品成人一区二区三区| 99热这里只有精品一区 | 精品久久久久久久毛片微露脸| 看免费av毛片| 久久亚洲精品不卡| 成年女人毛片免费观看观看9| 韩国精品一区二区三区| 麻豆成人午夜福利视频| 精品一区二区三区视频在线观看免费| 18美女黄网站色大片免费观看| 亚洲午夜理论影院| 99在线人妻在线中文字幕| 亚洲欧洲精品一区二区精品久久久| 国产成人系列免费观看| 免费在线观看亚洲国产| 日韩欧美 国产精品| 一区二区三区精品91| 久热爱精品视频在线9| 国产成人精品无人区| 中文字幕精品免费在线观看视频| 亚洲va日本ⅴa欧美va伊人久久| 久久久国产精品麻豆| 久久青草综合色| 99精品欧美一区二区三区四区| 国产人伦9x9x在线观看| 婷婷六月久久综合丁香| 欧美日韩亚洲国产一区二区在线观看| 亚洲国产欧美日韩在线播放| 欧美激情高清一区二区三区| 色尼玛亚洲综合影院| 日韩免费av在线播放| 亚洲国产精品成人综合色| 精品国内亚洲2022精品成人| 国产成人系列免费观看| 这个男人来自地球电影免费观看| 丁香六月欧美| 日韩成人在线观看一区二区三区| 99国产精品一区二区蜜桃av| 久久久久精品国产欧美久久久| 一区二区三区激情视频| av在线天堂中文字幕| 亚洲精品国产一区二区精华液| 女同久久另类99精品国产91| 黄片小视频在线播放| 非洲黑人性xxxx精品又粗又长| 岛国在线观看网站| 久久久久久久久久黄片| 欧美黄色淫秽网站| 久热爱精品视频在线9| 久久久久久国产a免费观看| 亚洲第一欧美日韩一区二区三区| 国产精品一区二区精品视频观看| 亚洲精品美女久久av网站| 久久草成人影院| 亚洲欧美日韩无卡精品| 国产97色在线日韩免费| 婷婷精品国产亚洲av在线| 热99re8久久精品国产| 亚洲专区中文字幕在线| 国产精品美女特级片免费视频播放器 | 热re99久久国产66热| 久久久精品欧美日韩精品| 欧美乱色亚洲激情| 免费看美女性在线毛片视频| 人人妻人人看人人澡| 亚洲av日韩精品久久久久久密| 啦啦啦观看免费观看视频高清| 亚洲av成人av| 欧美久久黑人一区二区| 久久中文看片网| 最近最新中文字幕大全电影3 | 国产主播在线观看一区二区| 国产97色在线日韩免费| 欧美又色又爽又黄视频|