• <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 ?

    Model for Asymmetry of Shock/Boundary Layer Interactions in Nozzle Flows

    2018-03-29 07:36:03,

    1.College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,P.R.China;

    2.Department of Aerospace Engineering,Nanjing University of Science and Technology,Nanjing 210094,P.R.China

    Nomenclature

    AArea

    aSonic speed

    hHeight of separation bubble

    L1Length of separation bubble

    L2Distance between the top of separation bubble and reattachment point

    MaMach number,mass

    MacConvective Mach number

    Mass flow rate

    NPR Nozzle pressure ratio,p0/pa

    pPressure

    rVelocity ratio across mixing layer

    sDensity ratio across mixing layer

    TTime

    uVelocity

    VVolume

    α Nozzle divergence angle

    γ Specific heat ratio

    Γ Index for flow asymmetry

    δ2Vertical coordinate of the edge of mixing layer on low-velocity side

    δwLocal thickness of mixing layer

    η Similarity variable

    ρ Density of fluid

    Φ Normalized spreading rate of mixing layer

    Subscripts

    0 Stagnation state at nozzle entrance

    1 High-velocity side of mixing layer

    2 Low-velocity side of mixing layer

    a Ambient condition

    b Separation bubble

    e Entrainment

    ex Nozzle exit

    m Averaged

    0 Introduction

    Asymmetry phenomenon of shock/boundary layer interaction(SBLI)in a completely symmetric duct with symmetric flow conditions,e.g.,an asymmetric shock(see Fig.1),has been observed frequently by many researchers.The reason for the flow asymmetry is still an open question,and is clarified neither by experiment nor computational fluid dynamics(CFD)[1].

    Fig.1 Experimental schlieren of asymmetric lambda shock in a planar nozzle[2]

    When a supersonic nozzle is operated at pressure ratio well below its design point,a shock system forms inside the nozzle and SBLI comes into being,which probably separates flow downstream of the shock from the nozzle walls and brings an asymmetric flowfield.The asymmetry in the nozzle flow can yield dangerous lateral forces,the so-called side-loads,which may damage the nozzle[1].Lawrence[3]studied the nature of flow asymmetry in planar and axisymmetric nozzles.He observed different symmetric and asymmetric flow structures.Papamoschou et al.[2]experimentally investigated the supersonic nozzle flow separation inside planar convergentdivergent nozzles.Their study shows that for the area ratio of nozzle exit to its throatAe/At≥1.4 and NPR>1.4,the flow pattern is asymmetric.This asymmetry does not flip during agiven test run,but it can change from one wall to the other and from one run to the next.This phenomenon was also observed by Shimshi et al.[4].Bourgoing et al.[5]found that shock configuration in a Mach 2planar nozzle is transformed from a symmetric pattern to an asymmetric one and asymmetric one again with the variation of NPR.A series of largeeddy simulations(LES)were conducted by Olson et al.[6]to model the asymmetry and unsteadiness of the SBLI in the planar nozzles tested by Ref.[2].

    Based on the aforementioned research on the asymmetry of SBLI in nozzles,some basic conclusions can be drawn:

    (1)Asymmetry of confined SBLI is closely relevant to the strength of SBLI,i.e.,the shock intensity and the confinement level.

    (2)Asymmetry of SBLI has a flipping phenomenon,i.e.,asymmetric shock system can flip between two sides of a nozzle.Flipping does not happen during agiven test run in nozzle experiments,but could takes place between runs.

    The reason for the asymmetry of confined SBLI is not clear yet,but many researcher,e.g.,Lawrence[3],Papamoschou et al.[2], Myshenkov[7], Wang[8],attributed it to Coanda effect which is used for the tendency of a fluid jet issuing tangentially on to a curved or angled solid surface to adhere to it[9].The entrainment of jet on ambient fluid is regarded as the cause for Coanda effect,but so far it has not been understood completely yet[10],even though it has been applied widely in industry.Coanda effect was confirmed experimentally by Allery et al.[11]to work in symmetrical configurations as it does in the single wall case:the jet reattaches randomly to either of two walls.

    The study is motivated by the research of Piponniau et al.[12]who proposed a model based on the properties of fluid entrainment in the mixing layer to explain low frequency unsteadiness on shock induced separation.Due to the close relation between his model and Coanda effect,Piponniau′s model is developed further here to explain the reason for the asymmetry of SBLI in an overexpanded nozzle whose flowfield data were obtained by numerical simulations.

    1 Theory

    1.1 Aerodynamic scheme

    According to Piponniau et al.[12],when a separation bubble is produced by SBLI(Fig.2),in the first part of the bubble,that is from the separation line,eddies are formed in the mixing layer zone(the reversed flow in the separation bubble is regarded as the other stream)and grow as it moves downstream.Fluid from the separated zone is entrained by the mixing layer.Near the middle of bubble(where the mixing layer has the maximum thickness),these eddies are shed into the downstream flow,bringing with them their mass,momentum and vortices outside the separated region.This generates,in the recirculating region,a default of mass that increases over time.Therefore, when the flow reattaches downstream,the mass amount inside the bubble decreases.

    Fig.2 Sketch of the entrainment of mixing layer on separation bubble[12]

    Now we consider the situation of asymmetric SBLI in a 2Dnozzle,whose flowfield pattern is sketched in Fig.3.Coanda effect works in this flow,entrainment of mixing layer on separation bubble on the upper wall decreases the mass and pressure inside the bubble,and the opposite phenomena happen on the lower wall.The pressure difference between two sides deflects the flow behind the shock to the upper wall.To understand how the result of asymmetry takes place,an imaginary symmetric flowfield,which is supposed to be the situation before the asymmetric flow pattern appearing,is sketched in Fig.4.Prior to create the asymmetry model,three assumptions are made in this situation:

    (1)Based on the feature of Conada effect introduced in Introduction,it is assumed that the entrainment of mixing layer only activates on one side,while the separation bubble on the other side keeps constant.

    Fig.3 Asymmetric SBLI pattern in a 2Dnozzle

    (2)After the shedding of eddies,the mass and pressure decrease inside the bubble but its size keeps constant.

    (3)If the final flow is still symmetric,a new amount of reversed flow from downstream enters the bubble at reattachment pointRto insure the balance[13].

    In the plane reflected shock case,large vortices are shed downstream at the position where the mixing layer reaches its maximum thickness,i.e.,the position with maximum separation bubble thickness,which is approximately at the middle of separation bubble[14].But for SBLI in a nozzle,the situation is a little different,the divergent wall leads to slender rear of separation bubble,and the maximum thickness of the bubble lies in the front of it instead of the middle as the plane case.Therefore,the shedding position for large vortices is still regarded as the position with the maximum bubble thickness in the nozzle case,but not at the middle of bubble.The distance from large vortices shedding position to the reattachment point is denoted asL2(Fig.4).

    Fig.4 Imaginary symmetric SBLI flowfield before asymmetric flow taking place in a 2Dnozzle

    Based on the above assumptions and deduction,now we can discuss the total mass entrained from separation bubble.Total entrained mass is the product of entrainment mass ratem·eand entrainment timeTe.The rate of mass entrainment can be obtained from Piponniau′s model,which will be deduced later.According to the third assumption,the distance between mass escaping from the bubble and mass returning into the bubble isL2,and then the time used for entrainment is given by

    wherea2is the sonic speed on the low-velocity side of the mixing layer.

    With the total entrained mass,the pressure inside the bubble after entrainment can be obtained based on the second assumption.Finally,the deflection angle of the flow will be obtained from the longitudinal momentum conservation equation,which will be compared with the actual deflection angle of the flow.

    1.2 Theoretical model for flow deflection with entrainment

    According to entrainment model of Piponniau′s,the separation bubble is approximated by a triangle of lengthL1and heighth(Fig.2),with an average density ofρm,then the air mass in the bubble by unit span is given by

    And rate of mass entrainment[11]

    whereδ2(x)is the vertical coordinate of the edge of the mixing layer on the low-velocity side,y0(x)the vertical coordinate of the centerline of the mixing layer,andx0=L3=L1-L2the position where large eddies shed,ηis the similarity variable,and the constantC0.14.δwandδ′ware the local thickness and the spreading rate of the mixing layer,respectively,and the latter can be expressed by the following relation according to Ref.[15]

    Φ (Mac)must be determined via experiment[17]and Fig.5gives its empirical value depending on the convective Mach number.Piponniau et al.[12]introduced a functiongas

    Fig.5 Normalized spreading rate as a function of the convective Mach number[12]

    Finally,the rate of mass entrainment is obtained.

    Consequently,we discuss the pressure variation in the bubble.The total mass of entrainment

    Based on the second assumption,the volume of bubble keeps constant,and the temperature in the bubble can be considered as invariant,then the density and pressure in the bubble after entrainment

    wherepmis the average pressure in the bubble.Then according to the first assumption,the pressure difference between two sides in the nozzle is obtained.

    With the pressure difference obtained from the above,we can calculate the deflection angle of flow,concerning the vertical momentum conservation for the control volume in Fig.4.

    whereL1is the length of separation bubble in the imaginary symmetric flow,pexthe pressure at nozzle exit,hexthe mainstream height at nozzle exit,αis the nozzle divergence angle,andβis the deflection angle of flow from horizontal direction on the nozzle symmetry plane (Fig.3).Then,from Eq.(13)we obtain

    The above asymmetry model is deduced based the nozzle flow with closed separation bubble, namely, restricted shock separation(RSS)[1].When the separation zone is open to the ambiance,namely,free shock separation(FSS)(Fig.6),although the situation is a little different from RSS,the theoretical model created above is still applicable in this case.Now separation lengthL1is the distance from the onset of separation to the nozzle exit,andL2the distance from the position with maximum separation thickness to the nozzle exit.

    Fig.6 Imaginary symmetric nozzle SBLI flowfield with FSS

    2 Model Application Based on Numerical Results of a Nozzle

    2.1 Nozzle geometry and numerical methods

    Simulations were conducted to obtain the detailed features of asymmetric SBLI in a planar nozzle.The nozzle model chosen for simulation is aplanar nozzle tested by Papamoschou et al.[2]and simulated by Xiao et al.[18],which has a throat height of 22.9mm,a length of 117mm and an area ratio(the area ratio of nozzle exit to throat)of 1.5.The nozzle is″trumpet-shaped″with the wall angle increasing monotonically from throat to exit.The maximum nozzle divergence angle is 3.83°.

    To apply the asymmetry model proposed above,forced symmetric(half)and full nozzle model were simulated,respectively.The Reynolds-averaged governing equations for compressible turbulent flow with a two equation SST turbulence model in CFX software was employed to simulate idea gas(γ=1.4)steady flows.The grid used in the simulations has a higher density near the wall and the minimum first grid point from the wall givesy+<1.The total number of grids used is 89 800for the full model and 51 900for the half model.Adiabatic,no slip wall boundary condition was specified for all the walls in these simulations.

    Computations were made for NPR between 1.20and 2.40by changing the total pressure at the nozzle entrance.Other boundary conditions were imposed as follows:The ambient pressure surrounding nozzle exitpa=101 325Pa,total temperature at nozzle entranceTt0=290K.

    2.2 Numerical results of asymmetric SBLI in full nozzle

    Fig.7shows the pressure distributions on the two walls of the nozzle from simulations and experiments at two NPRs (the abscissa is normalized by the height of nozzle throathtand the vertical axis is normalized by total pressure at nozzle entrancept0).Note that the nozzle throat is located atx=0.It can be seen that the flow is symmetric at NPR = 1.27and is asymmetric at NPR=1.61based on both numerical and experimental data.At NPR=1.61,though both numerical and experimental results give the asymmetric flowfield,the deflection direction of flow is opposite:The flow from simulation is deflected downward while that from experiment is deflected upward,which is caused by the randomicity of Coanda effect(entrainment)mentioned in Section 1.The shock positions from simulations are a little more upstream than experimental data,except this difference numerical results are satisfactory.

    Fig.7 Wall pressure distributions of the nozzle from simulations and experiments

    Three typical flow patterns at different NPRs are shown with numerical schlieren in Fig.8.At NPR=1.27,a symmetric flowfield with RSS on two sides is presented as Fig.8(a).At NPR=1.61,an asymmetric flowfield with FSS on one side and RSS on the other side appears as Fig.8(b).At NPR=2.40,a symmetric flowfield with FSS on two sides is obtained as Fig.8(c).

    Fig.8 Typical flow patterns in an over-expanded nozzle with numerical schlieren

    Deflection angle of nozzle exit flow at different NPRs are shown in Fig.9 (squares).It can be seen that the flow in the nozzle is symmetric as Fig.8(a)when NPR≤1.27,while it is asymmetric as Fig.8(b)after that and deflection angle becomes larger and larger with increasing NPR up to 2.10where the peak asymmetry reaches.Then,the flow returns to be symmetric as Fig.8(c)when NPR>2.20.

    Fig.9 Deflection angle of flow in the nozzle exit from full nozzle simulations and theoretical results

    2.3 Model application based on numerical results of half nozzle with forced symmetry

    The nozzle flowfields with forced symmetry were computed to apply the asymmetry model.The numerical results show that the flows with RSS (Fig.10(a))were obtained when NPR≤1.61,while the flowfields with FSS (Fig.10(b))were attained when NPR≥1.70.According to Eq.(14),the theoretical values of deflection angle of flow at nozzle exit at different NPRs have been calculated,which have been shown in Fig.9(triangles).One can see that there is a large difference between the results from theoretical model and actual deflection from full nozzle simulations.Theoretical results give a peak of deflection angle at NPR=1.47and then decrease gradually,which are close to the deflection of full nozzle only around NPR =1.70and NPR ≥2.30.The results show that there may be other factors to control the flow asymmetry besides Coanda effect.Table 1gives the aerodynamic parameters of the separation at typical NPRs.

    Fig.10 Numerical schlieren and streamlines of nozzle flow with forced symmetry

    Fig.11gives averaged pressure in the larger separation of full nozzle and in the separation of half nozzle with force symmetry,which shows averaged pressure in the separation on the side without entrainment is nearly constant before and after flow deflection at most NPRs except NPR=1.34,and consequently proves the validity of the first assumption in Section 1.1.

    Fig.11 Averaged pressure in the separation

    Table 1 Aerodynamic parameters of separation at typical NPRs for half nozzle with forced symmetry

    3 Conclusions

    A model for the asymmetry of SBLI in nozzle flows has been proposed based on the properties of fluid entrainment in the mixing layer and momentum conservation.Deflection angles obtained from the theoretical model based on the simulation results of a half nozzle with forced symmetry show a large difference from those of the actual full nozzle,which shows there should be other factors to control the flow asymmetry besides Coanda effect(or entrainment),and the entrainment of shear layer on the separation induced by SBLI is just one of causes for the asymmetry.

    Acknowledgements

    This work was supported by the National Natural Science Foundations of China(Nos.51476076,51776096).

    [1] HADJADJ A,ONOFRI M.Nozzle flow separation[J].Shock Waves,2009,19(4):163-169.

    [2] PAPAMOSCHOU D,ZILL A,JOHNSON A.Supersonic flow separation in planar nozzles[J].Shock Waves,2009,19(3):171-183.

    [3] LAWRENCE R A.Symmetrical and unsymmetrical flow separation in supersonic nozzles:Research Report Number 67-1[R].[S.l.]:Southern Methodist U-niversity,1967.

    [4] SHIMSHI E,BEN-DOR G,LEVY A,et al.Experimental investigation of asymmetric and unsteady flow separation in high Mach number planar nozzles[C]∥Proceedings of the 28th International Symposium on Shock Waves.Manchester:[s.n.],2011.

    [5] BOURGOING A,REIJASSE P.Experimental analysis of unsteady separated flows in a supersonic planar nozzle[J].Shock Waves,2005,14(4):251-258.

    [6] OLSON B J,LELE S K.A mechanism for unsteady separation in over-expanded nozzle flow[J].Physics of Fluids,2013,25:110809.

    [7] MYSHENKOV E V.Hysteresis phenomena in a plane rotatable nozzle[J].Fluid Mechanics,2010,45(4):667-678.

    [8] WANG T S.Transient two-dimensional analysis of side load in liquid rocket engine nozzles:AIAA 2004-3680[R].USA:AIAA,2004.

    [9] NEUENDORF R,WYGNANSKI I.On a turbulent wall jet flowing over a circular cylinder[J].J Fluid Mech,1999,381:1-25.

    [10]MIOZZI M,F(xiàn)RANCESCO L,ROMANO G P.Experimental investigation of a free-surface turbulent jet with Coanda effect[C]∥15th Int Symp on Applications of Laser Techniques to Fluid Mechanics.Lisbon,Portugal:[s.n.],2010.

    [11]ALLERY C,GUERIN S,HAMDOUNI A,et al.Experimental and numerical POD study of the Coanda effect used to reduce self-sustained tones[J].Mechanics Research Communications,2004,31:105-120.

    [12]PIPONNIAU S,DUSSAUGE J P,DEBIEVE J F,et al.A simple model for low-frequency unsteadiness in shock induced separation[J].J Fluid Mech,2009,629:87-108.

    [13]SIMPSON R L.Turbulent boundary-layer separation[J].Annu Rev Fluid Mech,1989,21:205-234.

    [14]DUPONT P,HADDAD C,DEBIEVE J F.Space and time organization in a shock induced boundary layer[J].J Fluid Mech,2006,559:255-277.

    [15]PAPAMOSCHOU D,ROSHKO A.The compressible turbulent shear layer:An experimental study[J].J Fluid Mech,1988,197:453-477.

    [16]BROWAND F K,TROUTT T R.The turbulent mixing layer:Geometry of large vortices[J].J Fluid Mech,1985,158:489-509.

    [17]SMITS A J,DUSSAUGE J P.Turbulent shear layers in supersonic Flow[M].New York:AIP Press,2006:155-156.

    [18]XIAO Q,TSAI H M,PAPAMOSCHOU D.Numerical investigation of supersonic nozzle flow separation[J].AIAA J,2007,45(3):532-541.

    亚洲熟女精品中文字幕| 国产精品偷伦视频观看了| 日日啪夜夜撸| 国产精品99久久99久久久不卡 | 日日啪夜夜撸| 亚洲精品一区蜜桃| 欧美xxxx性猛交bbbb| av国产精品久久久久影院| 极品人妻少妇av视频| 欧美三级亚洲精品| 久热这里只有精品99| 三上悠亚av全集在线观看 | 日产精品乱码卡一卡2卡三| 久久热精品热| 日韩欧美 国产精品| 美女大奶头黄色视频| .国产精品久久| 亚洲,欧美,日韩| 午夜免费男女啪啪视频观看| 大香蕉久久网| h视频一区二区三区| 久久精品国产a三级三级三级| 狂野欧美白嫩少妇大欣赏| 国产成人免费无遮挡视频| 2018国产大陆天天弄谢| 日韩中字成人| 亚洲精品久久久久久婷婷小说| 亚洲欧美精品自产自拍| 亚洲性久久影院| 久久毛片免费看一区二区三区| 18禁裸乳无遮挡动漫免费视频| 91午夜精品亚洲一区二区三区| 国产在线视频一区二区| av专区在线播放| 韩国高清视频一区二区三区| 丰满少妇做爰视频| 久久久久人妻精品一区果冻| 成人国产麻豆网| 亚洲精品日韩在线中文字幕| 国产男女超爽视频在线观看| 少妇被粗大的猛进出69影院 | av线在线观看网站| 国产中年淑女户外野战色| 久久韩国三级中文字幕| 男女边吃奶边做爰视频| 最黄视频免费看| 天天躁夜夜躁狠狠久久av| 欧美最新免费一区二区三区| 亚洲av成人精品一区久久| 欧美3d第一页| 热99国产精品久久久久久7| 亚洲,一卡二卡三卡| 一级片'在线观看视频| 国产熟女午夜一区二区三区 | 国产精品不卡视频一区二区| 中文在线观看免费www的网站| 午夜激情福利司机影院| 午夜91福利影院| 青青草视频在线视频观看| 777米奇影视久久| 欧美日韩视频精品一区| 男女免费视频国产| 九草在线视频观看| 国产成人精品一,二区| 男人狂女人下面高潮的视频| 亚洲综合精品二区| 高清av免费在线| 精华霜和精华液先用哪个| 国产免费一级a男人的天堂| 精品少妇黑人巨大在线播放| 自线自在国产av| 国产成人aa在线观看| 丰满少妇做爰视频| 偷拍熟女少妇极品色| 国产熟女午夜一区二区三区 | 少妇精品久久久久久久| 综合色丁香网| 极品人妻少妇av视频| 中文天堂在线官网| 亚洲国产精品999| 中文在线观看免费www的网站| 男人狂女人下面高潮的视频| 中文乱码字字幕精品一区二区三区| 少妇裸体淫交视频免费看高清| 亚洲av福利一区| 日韩中字成人| 精品少妇久久久久久888优播| 欧美bdsm另类| 只有这里有精品99| 交换朋友夫妻互换小说| 99精国产麻豆久久婷婷| 尾随美女入室| 久久婷婷青草| 一个人免费看片子| 亚洲精品乱码久久久v下载方式| 三上悠亚av全集在线观看 | 夫妻性生交免费视频一级片| 人妻一区二区av| 人人妻人人爽人人添夜夜欢视频 | 精品少妇黑人巨大在线播放| 国产精品不卡视频一区二区| 亚洲人成网站在线观看播放| 日本91视频免费播放| 成年av动漫网址| 亚洲国产成人一精品久久久| 色视频www国产| 黄色视频在线播放观看不卡| 国产精品熟女久久久久浪| 人妻人人澡人人爽人人| 高清不卡的av网站| 国产在线免费精品| 十八禁网站网址无遮挡 | 亚洲精品久久久久久婷婷小说| 一级毛片黄色毛片免费观看视频| 免费看光身美女| 亚洲久久久国产精品| 两个人免费观看高清视频 | 午夜日本视频在线| 三级经典国产精品| 日韩成人伦理影院| 男女无遮挡免费网站观看| 亚洲av综合色区一区| 欧美3d第一页| 欧美3d第一页| 欧美成人精品欧美一级黄| 久久精品国产亚洲网站| 在线免费观看不下载黄p国产| 女性被躁到高潮视频| 久久国内精品自在自线图片| 日韩亚洲欧美综合| 最近手机中文字幕大全| 热re99久久国产66热| 毛片一级片免费看久久久久| 国国产精品蜜臀av免费| av免费在线看不卡| 亚洲自偷自拍三级| 男女国产视频网站| 成人漫画全彩无遮挡| 国产高清有码在线观看视频| 卡戴珊不雅视频在线播放| 久久午夜福利片| 在线 av 中文字幕| 2021少妇久久久久久久久久久| 一本久久精品| 高清欧美精品videossex| 2021少妇久久久久久久久久久| 国产片特级美女逼逼视频| 99久久精品国产国产毛片| 水蜜桃什么品种好| 成人毛片60女人毛片免费| 九草在线视频观看| 国产精品.久久久| 国产欧美亚洲国产| 亚洲成人av在线免费| 伊人亚洲综合成人网| 最新的欧美精品一区二区| 少妇人妻一区二区三区视频| 久久国产乱子免费精品| 欧美bdsm另类| 色吧在线观看| 日韩中文字幕视频在线看片| 噜噜噜噜噜久久久久久91| 视频中文字幕在线观看| 91精品国产国语对白视频| 在线观看美女被高潮喷水网站| av卡一久久| 国语对白做爰xxxⅹ性视频网站| 欧美 亚洲 国产 日韩一| 男人和女人高潮做爰伦理| 51国产日韩欧美| 啦啦啦啦在线视频资源| 狠狠精品人妻久久久久久综合| 日本91视频免费播放| 亚洲成人av在线免费| 日韩av不卡免费在线播放| 一区二区av电影网| 久久久久久久久大av| 免费av中文字幕在线| √禁漫天堂资源中文www| 一级毛片 在线播放| 国产男女内射视频| 男女边吃奶边做爰视频| 国产综合精华液| 99久久综合免费| 国模一区二区三区四区视频| 一本大道久久a久久精品| 少妇猛男粗大的猛烈进出视频| 大片免费播放器 马上看| 嫩草影院入口| 亚洲精品日本国产第一区| 一级黄片播放器| 黑人巨大精品欧美一区二区蜜桃 | 久久婷婷青草| 亚洲,欧美,日韩| 国产毛片在线视频| 国产精品国产av在线观看| 99国产精品免费福利视频| 夫妻性生交免费视频一级片| 91久久精品电影网| 婷婷色麻豆天堂久久| 久久精品久久久久久噜噜老黄| 精品久久久久久久久亚洲| 亚洲av男天堂| 一区二区三区四区激情视频| 一区二区三区四区激情视频| 国产亚洲精品久久久com| 成人特级av手机在线观看| 国产高清国产精品国产三级| 天美传媒精品一区二区| 精品卡一卡二卡四卡免费| 日本欧美国产在线视频| 纯流量卡能插随身wifi吗| 日日啪夜夜爽| 免费看不卡的av| 人妻制服诱惑在线中文字幕| 高清黄色对白视频在线免费看 | 天美传媒精品一区二区| 亚洲精品中文字幕在线视频 | 九九在线视频观看精品| 欧美激情极品国产一区二区三区 | 嫩草影院新地址| 人妻人人澡人人爽人人| 纯流量卡能插随身wifi吗| 欧美日本中文国产一区发布| 久久久亚洲精品成人影院| 国产一区亚洲一区在线观看| 国产精品熟女久久久久浪| 久热这里只有精品99| 亚洲国产精品一区二区三区在线| 欧美精品一区二区免费开放| 黑人高潮一二区| 亚洲av电影在线观看一区二区三区| 高清av免费在线| 日本av手机在线免费观看| 一区二区三区乱码不卡18| 免费黄色在线免费观看| 国产深夜福利视频在线观看| 男女无遮挡免费网站观看| 不卡视频在线观看欧美| 边亲边吃奶的免费视频| 2022亚洲国产成人精品| 婷婷色综合大香蕉| 十分钟在线观看高清视频www | 亚洲va在线va天堂va国产| 三级国产精品片| 观看免费一级毛片| 人妻一区二区av| 人妻夜夜爽99麻豆av| 欧美日韩视频精品一区| 日韩中文字幕视频在线看片| 天美传媒精品一区二区| 国产片特级美女逼逼视频| 国产精品蜜桃在线观看| 成年女人在线观看亚洲视频| 亚洲av二区三区四区| 纵有疾风起免费观看全集完整版| 美女主播在线视频| 日本猛色少妇xxxxx猛交久久| 中文字幕av电影在线播放| 国产精品一区www在线观看| 中文字幕免费在线视频6| 少妇精品久久久久久久| 欧美激情国产日韩精品一区| 亚洲经典国产精华液单| 亚洲精品日韩在线中文字幕| 亚洲欧洲精品一区二区精品久久久 | 精品熟女少妇av免费看| 久久99精品国语久久久| 亚洲精品乱久久久久久| 黄色毛片三级朝国网站 | 国产精品久久久久久久电影| 国产一区二区三区av在线| 日韩中文字幕视频在线看片| 人人妻人人添人人爽欧美一区卜| 欧美 亚洲 国产 日韩一| 晚上一个人看的免费电影| 国产av一区二区精品久久| 99精国产麻豆久久婷婷| 日韩伦理黄色片| 搡老乐熟女国产| 嫩草影院入口| 久久99热6这里只有精品| 少妇精品久久久久久久| 日韩成人伦理影院| av福利片在线观看| 中文欧美无线码| 成人国产av品久久久| 午夜日本视频在线| 人人妻人人澡人人看| 亚洲情色 制服丝袜| 老司机影院成人| 高清毛片免费看| 国产伦精品一区二区三区四那| 色94色欧美一区二区| 日本与韩国留学比较| 自拍欧美九色日韩亚洲蝌蚪91 | 亚洲三级黄色毛片| 国产精品不卡视频一区二区| 在线天堂最新版资源| av免费观看日本| 噜噜噜噜噜久久久久久91| 热99国产精品久久久久久7| 国产精品蜜桃在线观看| 午夜影院在线不卡| 成年人免费黄色播放视频 | 国产深夜福利视频在线观看| 欧美老熟妇乱子伦牲交| 中文字幕人妻丝袜制服| 欧美bdsm另类| 亚洲欧洲精品一区二区精品久久久 | 中文精品一卡2卡3卡4更新| 亚洲色图综合在线观看| 热re99久久国产66热| 国产乱来视频区| 日本欧美视频一区| 免费看光身美女| 免费人妻精品一区二区三区视频| 久久人人爽人人爽人人片va| 一区二区三区乱码不卡18| 国产深夜福利视频在线观看| 精品人妻熟女毛片av久久网站| 精品人妻偷拍中文字幕| 亚洲精品乱久久久久久| 男男h啪啪无遮挡| 欧美日韩亚洲高清精品| 尾随美女入室| 纵有疾风起免费观看全集完整版| 99久久中文字幕三级久久日本| 啦啦啦视频在线资源免费观看| 国产无遮挡羞羞视频在线观看| 久久久精品免费免费高清| 精品熟女少妇av免费看| 亚洲av男天堂| 久久韩国三级中文字幕| 亚洲人成网站在线播| 人人妻人人爽人人添夜夜欢视频 | 一区在线观看完整版| 一级a做视频免费观看| 欧美日韩av久久| 国产欧美日韩精品一区二区| 男女免费视频国产| 日韩大片免费观看网站| 久久国产亚洲av麻豆专区| 亚洲精品456在线播放app| 尾随美女入室| 中文欧美无线码| 99九九线精品视频在线观看视频| 人妻少妇偷人精品九色| 日韩精品免费视频一区二区三区 | 观看av在线不卡| 亚洲色图综合在线观看| 狠狠精品人妻久久久久久综合| 国产探花极品一区二区| 欧美日韩在线观看h| 少妇裸体淫交视频免费看高清| 嘟嘟电影网在线观看| 尾随美女入室| 国产精品成人在线| 国产精品女同一区二区软件| 国产视频内射| 欧美老熟妇乱子伦牲交| 91aial.com中文字幕在线观看| 久久6这里有精品| 美女视频免费永久观看网站| 伦精品一区二区三区| 国产熟女午夜一区二区三区 | 一级a做视频免费观看| 精品国产国语对白av| 午夜影院在线不卡| 一级毛片黄色毛片免费观看视频| 一本—道久久a久久精品蜜桃钙片| 国产精品久久久久成人av| 在线观看免费视频网站a站| 国产永久视频网站| 97在线视频观看| 三级国产精品片| 国产探花极品一区二区| 亚洲国产av新网站| 亚洲va在线va天堂va国产| 亚洲三级黄色毛片| 国产亚洲5aaaaa淫片| 久久国产亚洲av麻豆专区| 国产一区有黄有色的免费视频| 汤姆久久久久久久影院中文字幕| 人人妻人人添人人爽欧美一区卜| 蜜桃久久精品国产亚洲av| 精品熟女少妇av免费看| 色哟哟·www| 中文字幕制服av| 91午夜精品亚洲一区二区三区| 日韩成人av中文字幕在线观看| 国产色婷婷99| 99久久精品热视频| 人妻少妇偷人精品九色| 国产成人精品福利久久| 亚洲精品国产色婷婷电影| 乱人伦中国视频| 如日韩欧美国产精品一区二区三区 | 日韩视频在线欧美| a级毛片在线看网站| 一区二区三区四区激情视频| 亚洲国产精品国产精品| 成人毛片a级毛片在线播放| 丰满迷人的少妇在线观看| 蜜桃久久精品国产亚洲av| av网站免费在线观看视频| 一级毛片电影观看| 性色av一级| 久久女婷五月综合色啪小说| 日韩大片免费观看网站| 春色校园在线视频观看| 欧美97在线视频| 在线观看av片永久免费下载| 人人澡人人妻人| 亚洲国产精品国产精品| 成年美女黄网站色视频大全免费 | 亚洲av福利一区| 亚洲精品第二区| 99国产精品免费福利视频| 草草在线视频免费看| 最近手机中文字幕大全| 少妇被粗大的猛进出69影院 | 免费av中文字幕在线| 国产女主播在线喷水免费视频网站| 在线观看免费日韩欧美大片 | 寂寞人妻少妇视频99o| 国产精品国产三级国产av玫瑰| 成年人午夜在线观看视频| 国产午夜精品一二区理论片| 亚洲精品日韩av片在线观看| 国产日韩欧美在线精品| 三级经典国产精品| 日韩中字成人| 欧美 亚洲 国产 日韩一| 91精品一卡2卡3卡4卡| 精品国产一区二区久久| 精品一区二区三区视频在线| 熟女av电影| 免费播放大片免费观看视频在线观看| 亚洲国产最新在线播放| 亚洲丝袜综合中文字幕| 黄片无遮挡物在线观看| 亚洲高清免费不卡视频| 亚洲丝袜综合中文字幕| 国产真实伦视频高清在线观看| 中文字幕av电影在线播放| 日韩精品免费视频一区二区三区 | 夫妻午夜视频| 黑人巨大精品欧美一区二区蜜桃 | 热99国产精品久久久久久7| 中文资源天堂在线| 日韩大片免费观看网站| 久久精品久久久久久久性| 高清午夜精品一区二区三区| 成人漫画全彩无遮挡| 丝袜喷水一区| 亚洲天堂av无毛| 下体分泌物呈黄色| 91aial.com中文字幕在线观看| 精品少妇黑人巨大在线播放| 免费观看a级毛片全部| 免费观看的影片在线观看| 亚洲精华国产精华液的使用体验| 少妇人妻 视频| 欧美3d第一页| 久久热精品热| 免费观看性生交大片5| 久久久久久久亚洲中文字幕| 午夜福利网站1000一区二区三区| 久久综合国产亚洲精品| 国产色爽女视频免费观看| 国产真实伦视频高清在线观看| 午夜福利影视在线免费观看| 人妻一区二区av| 色吧在线观看| 性色av一级| 国内少妇人妻偷人精品xxx网站| 国产成人免费无遮挡视频| 美女中出高潮动态图| 欧美日韩精品成人综合77777| 国产淫片久久久久久久久| 伦精品一区二区三区| 亚州av有码| 在线亚洲精品国产二区图片欧美 | 黄色一级大片看看| 777米奇影视久久| 中文字幕亚洲精品专区| 91午夜精品亚洲一区二区三区| 精品卡一卡二卡四卡免费| 国产精品不卡视频一区二区| www.色视频.com| 欧美3d第一页| 纵有疾风起免费观看全集完整版| 亚洲欧美日韩卡通动漫| 欧美一级a爱片免费观看看| 日本午夜av视频| 国产精品熟女久久久久浪| www.av在线官网国产| 日韩av免费高清视频| av黄色大香蕉| 日本av免费视频播放| 日韩亚洲欧美综合| 亚洲国产日韩一区二区| 少妇的逼好多水| 国产乱人偷精品视频| 国产午夜精品久久久久久一区二区三区| 美女cb高潮喷水在线观看| 在线精品无人区一区二区三| 亚州av有码| 精品99又大又爽又粗少妇毛片| 精品人妻偷拍中文字幕| 日韩欧美精品免费久久| h视频一区二区三区| 菩萨蛮人人尽说江南好唐韦庄| 国产日韩欧美视频二区| 天堂中文最新版在线下载| 久久 成人 亚洲| 少妇的逼水好多| 亚洲av成人精品一二三区| 国产中年淑女户外野战色| 精品熟女少妇av免费看| 在线观看免费高清a一片| 久久久a久久爽久久v久久| 高清黄色对白视频在线免费看 | 精品视频人人做人人爽| 亚洲伊人久久精品综合| 亚洲精品中文字幕在线视频 | 一本—道久久a久久精品蜜桃钙片| 亚洲国产成人一精品久久久| 久久久午夜欧美精品| 国产色婷婷99| 欧美日韩视频精品一区| 亚洲精品第二区| 久久久午夜欧美精品| 亚洲av电影在线观看一区二区三区| 欧美一级a爱片免费观看看| 久久精品国产自在天天线| 最近2019中文字幕mv第一页| 欧美xxⅹ黑人| 嫩草影院入口| 日本黄色日本黄色录像| 亚洲国产精品一区三区| 青春草视频在线免费观看| 亚洲伊人久久精品综合| 蜜桃久久精品国产亚洲av| 国产精品偷伦视频观看了| 麻豆成人午夜福利视频| 国产av码专区亚洲av| 啦啦啦视频在线资源免费观看| 色5月婷婷丁香| 日韩强制内射视频| 在线观看一区二区三区激情| 草草在线视频免费看| 特大巨黑吊av在线直播| 免费高清在线观看视频在线观看| av女优亚洲男人天堂| 高清午夜精品一区二区三区| 在线观看免费高清a一片| 亚洲国产日韩一区二区| 中国国产av一级| 久久久精品免费免费高清| 午夜激情久久久久久久| 丝袜喷水一区| 少妇人妻久久综合中文| 久久久久久人妻| av免费观看日本| 国产无遮挡羞羞视频在线观看| 亚洲精品久久久久久婷婷小说| 丝袜脚勾引网站| 欧美三级亚洲精品| 亚洲va在线va天堂va国产| 波野结衣二区三区在线| 91精品国产国语对白视频| 看免费成人av毛片| 日本av手机在线免费观看| 伦精品一区二区三区| 一级二级三级毛片免费看| 人人妻人人看人人澡| 国产亚洲最大av| 日韩精品免费视频一区二区三区 | 中文字幕av电影在线播放| 国产黄片美女视频| 欧美日韩国产mv在线观看视频| 国产探花极品一区二区| 一级毛片久久久久久久久女| 国产精品人妻久久久久久| 日韩强制内射视频| 国产成人午夜福利电影在线观看| 多毛熟女@视频| 80岁老熟妇乱子伦牲交| 亚洲欧洲日产国产| 欧美97在线视频| av又黄又爽大尺度在线免费看| 成人美女网站在线观看视频| 日韩中文字幕视频在线看片| 日本欧美视频一区| 久久人人爽人人爽人人片va| 精品一区二区三卡| 亚洲美女视频黄频| 久久久久久久国产电影| 26uuu在线亚洲综合色| 成年av动漫网址| 精华霜和精华液先用哪个| 国产91av在线免费观看| 国内揄拍国产精品人妻在线| 黑人巨大精品欧美一区二区蜜桃 | 亚洲四区av| 国产白丝娇喘喷水9色精品| 久久国产亚洲av麻豆专区| 国产男女超爽视频在线观看| 亚洲va在线va天堂va国产| 免费观看av网站的网址| 日韩亚洲欧美综合| 精品人妻偷拍中文字幕| 免费在线观看成人毛片|