• <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 ?

    Some notes on numerical simulation and error analyses of the attached turbulent cavitating flow by LES *

    2018-05-14 01:43:32XinpingLong龍新平YunLong龍云WentingWang王文婷HuaiyuCheng程懷玉BinJi季斌
    關(guān)鍵詞:龍云新平

    Xin-ping Long (龍新平), Yun Long (龍云), Wen-ting Wang (王文婷), Huai-yu Cheng (程懷玉),Bin Ji (季斌)

    1. State Key Laboratory of Water Resources and Hydro power Engineering Science, School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China

    2. Key Laboratory of Jet Theory and New Technology of Hubei Province, Wuhan University, Wuhan 430072,China

    It is a great challenge for both experiment and numerical simulation to investigate the complicated transient cavitating flow. It is noted that numerical simulation of cavitating flow has achieved a remarkable progress in the last two decades. Li et al.[1,2]propose an improved all-speed Roe scheme for LES and obtain satisfactory results. The re-entrant jet[3]and shock wave[4]has attracted much attention. Peng et al.[5]observe the U-type fl ow structures around the hydrofoils in the cavitation tunnel. Ji et al.[6], Wang et al.[7], Long et al.[8]and Cheng et al.[9]study transient cavitating flow structure by high performance numerical methods and three-dimensional Lagrangian technology.

    All these researches enhance the understanding of the transient cavitating flow. However, less attention are paid to assessing the accuracy of these numerical results with systematic methodology and procedures. Verification and validation (V&V) is a basic procedure to evaluate the accuracy and reliability of numerical simulation, but the practical use of LES V&V is a big challenge[10]. Related studies of LES V&V are ongoing[11]. Freitag and Klein[12]have proposed a systematic grid and model variation method to estimate the numerical and modeling error.Xing[11]proposes a general framework for V&V of LES to get the numerical, modeling and their coupling errors. The investigations by Dutta and Xing[13]have achieved promising achievements.

    Inspired by the aforementioned studies, this letter carries out the large eddy simulation and error analysis of the attached turbulent cavitating flow around the Clark-Y hydrofoil. Comparisons between available experiments[14]and numerical results have been made. Quantitative analyses of LES errors are presented and cavitation influence on LES errors is also discussed.

    The chord lengthCof hydrofoil is 0.07 m and angle of attack is 8°. The length, width and height of the computational domain are 10.0C, 0.3Cand 2.7C, respectively. The boundary inlet velocity is set asU∞=10m/s , and outlet boundary is fixed at the static pressure pout, deriving from the cavitation number σ=0.8 (σ=(pout-pv)/(0.5ρU∞2)), wherepvis the saturated vapor pressure andρis the liquid density). Detailed information about the setup can see Ref. [15]. Case 1 is refined with the same mesh topology from Case 3, and Case 2 is the same as Case 1 except for the change of Smagorinsky constant.Detail information about mesh, model constant and calculations setup has been displayed in Table 1.

    Table 1 Mesh and model constant and calculation setup

    Herein, the LES errors estimation method, proposed by Freitag and Klein[12], has been employed.Some revised thoughts by Xing[11]have been adopted in this paper considering that the time step and grid spacing changing simultaneously. The numerical error and modeling error are estimated with power series expansions as a function ofh*and Δ:

    whereSCis the numerical benchmark,S1,S2,S3denotes the standards LES solution, the LES solution with a modified model contribution and solution on a coarser mesh, respectively.cNandcMare the unknown coefficient. The local spatial and temporal resolutionh*[11]is defined as

    where Δtis the time step andhis the local mesh size. Herehis equal to the filter width Δ. The model variation factor α=1.3. The time step and grid spacing share the same refinement ratior=1.6.pNandpMhas a large effect on the LES errors estimations.pN=1.7 andpM=1.5 were recommended by Dutta and Xing[16], whilepN=2 andpM=2/3 by Freitag and Klein[12]have been investigated and applied in some researches. Therefore,pN=2 andpM=2/3 are adopted in this paper.

    The numerical error and modeling error for case1 are corresponding to the first term and second term on the right hand sides of Eq. (1). The normalized averaged stream wise velocityu/U∞is chosen as the target variable to gain the numerical and modeling error. The velocity and cavitation data are obtained from the medial surface along the span wise location.

    Figure 1 shows the comparison of experimental and numerical snapshots of cavity shedding within one typical cycle. The experimental results are from Ref. [14]. Numerical results are used to represent the unsteady cavity evolution colored with vertical velocity. From Figs. 1(a)-1(d), it can be observed that the numerical results can capture the unsteady cavity evolution features, including the cavity inception,development and shedding along the hydrofoil suction face. The periodic cavity shedding behavior can lead to complex and turbulent flow structures. This can cause huge difficulties to accurately simulate the unsteady cavitating flow even with well performance numerical methods. Owing to the extensive use of LES in academic research in recent years, the reliability or risk assessment has become an essential step for LES results in cavitation. At present, it has the possibility to carry out quantitative LES errors analysis in cavitation simulation. Verification and validation of LES will be a necessary procedure in the future.

    Fig.1 (Color online)Timeevolution of cavity shedding in one typical cycle for Case1 (Left: Experimental results[14].Right: Cavitation patterns by iso-surface of αv=0.1)

    Figure 2 presents the average values versus different flow time about the normalized stream wise velocityu/U∞at monitoring point A (x/c=0.2,y/c=0.09) and point B (x/c=0.8,y/c=0.16). It can be seen that the variations ofu/U∞at the ending of statistical flow time are clearly smaller compared to the beginning of flow time. This ensures that the selection of final averaged velocity in this paper has almost no effect on obtaining the LES errors.

    Fig.2 Average values versus different flow time about the normalized stream wise velocities at monitoring points

    The magnitudes of numerical error and modeling error for Case 1 are shown in Fig.3 for the unsteady cavitating flow. From the results, it can be seen that the modeling error and numerical error are almost on the same order of magnitude in most situations, while the modeling error is often a bit larger if compared to numerical error. For each chord wise location in Fig.3,the numerical error and modeling error sometimes partially have opposite signs and they can offset each other. In Fig.3(a), the errors are large and squeezed in very little space at vertical direction, but sharply decrease to almost zero. The cavitation occurs generally around this narrow location, and the accuracy of the inner cavitating flow structure at this narrow location is a great difficulty for numerical simulation,also for experiments. This might be in charge of the error distribution in Fig.3(a). From Figs. 3(b)-3(e),the numerical and modeling errors start to oscillate along the vertical direction. The errors magnitudes and fluctuation levels gradually become larger fromx/c=0.4 tox/c=1.0. It has the similar tendency that the errors decrease to almost zero when the distance is far away from foil surface. The cavitation area becomes thicker from Figs. 3(b), 3(e). The velocity fluctuate sviolently due to the periodic cavity shedding,which can cause much large scale vortexstructure. It has a huge impact on the cavitation simulation. This might result in the errors changing in a large range. From above analyses, it can be con-cluded that the LES errors are significantly influenced by the unsteady cavitation.

    Fig.3 The numerical errors and modeling errors of averaged u/ U∞ at five chord wise locations for Case 1

    Large eddy simulation and error analyses of the attached turbulent cavitating flow around the Clark-Y hydrofoil has been made in this letter. Quantitative LES errors analyses of cavitation simulation are carried out and cavitation influence on LES errors is also discussed. The main conclusions can be summarized as follows:

    (1) The numerical results can capture the periodic cavity shedding behavior and they are in well agreement with the experiments. The shedding of cavity can lead to complex and turbulent flow structures,which results in great difficulties to model the details of the turbulent cavitating flow even with well performance numerical methods.

    (2) In this simulation of the transient cavitating flow, the modeling error and numerical error are on the same order of magnitude in most situations, while the modeling error is often a little bit larger than numerical error. The numerical error and modeling error sometimes have the opposite sign and they can partially offset each other.

    (3) The numerical error and modeling error are significantly influenced by the cavitation. The unsteady cavitation can extend the magnitudes and oscillation levels of LES numerical error and modeling error.

    It still has a long way to go for the quantitative LES reliability estimation with V&V. Owing to the extensive use of LES in academic research in recent years, the LES reliability estimation should become an essential part to LES results in cavitation. Due to that Smagorinsky constant cannot change arbitrarily, the LES error estimation method adopted in this paper needs more investigations. The three-equation method proposed by Dutta and Xing[16]may give more promising results. The LES error estimation applied in the unsteady cavitation simulation with the guideline of Ref. [16] will be the focus of our future investigations.

    [1] Li X. S., Li X. L. All-speed Roe scheme for the large eddy simulation of homogeneous decaying turbulence [J].International Journal of Computational Fluid Dynamics,2016, 30(1): 69-78.

    [2] Li X. S., Xu J. Z., Gu C. W. Preconditioning method and engineering application of large eddy simulation [J].Science in ChinaSeries G-Physics, Mechanics and Astronomy, 2008, 51(6): 667-677.

    [3] Wu Q., Huang B., Wang G. et al. The transient characteristics of cloud cavitating flow over a flexible hydrofoil[J].International Journal of Multiphase Flow, 2018, 99:162-173.

    [4] Cui P., Zhang A. M., Wang S. et al. Ice breaking by a collapsing bubble [J].Journal of Fluid Mechanics, 2018,841: 287-309.

    [5] Peng X. X., Ji B., Cao Y. et al. Combined experimental observation and numerical simulation of the cloud cavitation with U-type flow structures on hydrofoils [J].International Journal of Multiphase Flow, 2016, 79:10-22.

    [6] Ji B., Luo X., Arndt R. E. A. et al. Large eddy simulation and theoretical investigations of the transient cavitating vortical flow structure around a NACA66 hydrofoil [J].International Journal of Multiphase Flow, 2015, 68:121-134.

    [7] Wang Y., Xu C., Wu X. et al. Ventilated cloud cavitating flow around a blunt body close to the free surface [J].Physical Review Fluids, 2017, 2(8): 084303.

    [8] Long X., Cheng H., Ji B. et al. Large eddy simulation and Euler-Lagrangian coupling investigation of the transient cavitating turbulent flow around a twisted hydrofoil [J].International Journal of Multiphase Flow, 2018, 100:41-56.

    [9] Cheng H. Y., Long X. P., Ji B. et al. 3-D Lagrangian based investigations of the time-dependent cloud cavitating flows around a Clark-Y hydrofoil with special emphasis on shedding process analysis [J].Journal of Hydrodynamics,2018, 30(1): 122-130.

    [10] Long Y., Long X., Ji B. et al. Verification and validation of URANS simulations of the turbulent cavitating flow around the hydrofoil [J].Journal of Hydrodynamics, 2017,29(4): 610-620.

    [11] Xing T. A general framework for verification and validation of large eddy simulations [J].Journal of Hydrodynamics, 2015, 27(2): 163-175.

    [12] Freitag M., Klein M. An improved method to assess the quality of large eddy simulations in the context of implicit filtering [J].Journal of Turbulence, 2006, 7(40): 1-11.

    [13] Dutta R., Xing T. Quantitative solution verification of large eddy simulation of channel flow [C].Proceedings of the 2nd Thermal and Fluid Engineering Conference and 4th International Workshop on Heat Transfer, Las Vegas,USA, 2017.

    [14] Huang B., Young Y. L., Wang G. et al. Combined experimental and computational investigation of unsteady structure of sheet/cloud cavitation [J].Journal of Fluids Engineering, 2013, 135(7): 071301.

    [15] Ji B., Long Y., Long X. P. et al. Large eddy simulation of turbulent attached cavitating flow with special emphasis on large scale structures of the hydrofoil wake and turbulence-cavitation interactions [J].Journalof Hydrodynamics,2017, 29(1): 27-39.

    [16] Dutta R., Xing T. Five-equation and robust three-equation methods for solution verification of large eddy simulation[J].Journal of Hydrodynamics,2018, 30(1): 23-33.

    猜你喜歡
    龍云新平
    幼兒園里歡樂多
    幼兒園(2021年18期)2021-12-06 02:45:42
    小螞蟻去游玩
    幼兒園(2021年16期)2021-12-06 01:06:48
    老腔唱新歌
    金秋(2021年22期)2021-03-10 07:59:16
    出滇抗戰(zhàn)時期龍云對滇軍的治理研究
    創(chuàng)造(2020年6期)2020-11-20 05:58:42
    讓蘑菇
    幼兒園(2020年3期)2020-03-27 07:00:07
    劉新平 油畫作品
    An integral calculation approach for numerical simulation of cavitating flow around a marine propeller behind the ship hull *
    URANS simulations of the tip-leakage cavitating flow with verification and validation procedures *
    你總是給我力量
    Verification and validation of URANS simulations of the turbulent cavitating flow around the hydrofoil*
    国产高清激情床上av| 国产高清有码在线观看视频| 香蕉av资源在线| 熟女电影av网| 欧美性感艳星| 人人妻人人澡欧美一区二区| 欧美日韩精品网址| 久久久久国产精品人妻aⅴ院| 国产亚洲精品综合一区在线观看| 在线观看舔阴道视频| 成人国产综合亚洲| 国产乱人伦免费视频| 国产精品野战在线观看| 久久精品影院6| 久久99热这里只有精品18| 成人国产一区最新在线观看| 1000部很黄的大片| 两个人的视频大全免费| 亚洲一区二区三区色噜噜| 麻豆成人av在线观看| 国产亚洲精品久久久久久毛片| 亚洲人成网站在线播放欧美日韩| 在线免费观看不下载黄p国产 | 一进一出好大好爽视频| 国产精品久久视频播放| 最新美女视频免费是黄的| 亚洲专区国产一区二区| 丰满的人妻完整版| 男人的好看免费观看在线视频| 日本在线视频免费播放| 中文亚洲av片在线观看爽| 亚洲美女视频黄频| 午夜免费激情av| 一卡2卡三卡四卡精品乱码亚洲| 国产精品亚洲美女久久久| 亚洲精品一区av在线观看| 综合色av麻豆| 亚洲成a人片在线一区二区| 少妇的逼水好多| 每晚都被弄得嗷嗷叫到高潮| 天堂动漫精品| 一本久久中文字幕| 脱女人内裤的视频| 国产精品久久久久久亚洲av鲁大| 超碰av人人做人人爽久久 | 小说图片视频综合网站| 亚洲熟妇中文字幕五十中出| 国产成人av教育| 窝窝影院91人妻| 一区二区三区高清视频在线| 国产av不卡久久| 麻豆国产av国片精品| 99热这里只有是精品50| av在线蜜桃| 国产欧美日韩精品亚洲av| 久久久色成人| 国产激情偷乱视频一区二区| 亚洲自拍偷在线| 香蕉丝袜av| 欧美中文日本在线观看视频| 国产成人a区在线观看| 国产精品野战在线观看| 热99在线观看视频| 伊人久久精品亚洲午夜| 特级一级黄色大片| 国产亚洲精品久久久久久毛片| 亚洲精品在线观看二区| 草草在线视频免费看| 国产精品三级大全| 老司机午夜十八禁免费视频| 国产免费男女视频| 婷婷六月久久综合丁香| 国产精华一区二区三区| 看黄色毛片网站| 伊人久久大香线蕉亚洲五| 亚洲av日韩精品久久久久久密| 国产中年淑女户外野战色| 欧美高清成人免费视频www| 一进一出抽搐gif免费好疼| 国产一区二区亚洲精品在线观看| 日本撒尿小便嘘嘘汇集6| 91在线观看av| 最新中文字幕久久久久| 夜夜爽天天搞| 99热这里只有是精品50| 亚洲 国产 在线| 欧美性猛交黑人性爽| 在线免费观看不下载黄p国产 | 欧美丝袜亚洲另类 | 亚洲av成人精品一区久久| 亚洲中文字幕一区二区三区有码在线看| 国产精品一及| 午夜精品在线福利| 亚洲国产日韩欧美精品在线观看 | 国产av一区在线观看免费| 麻豆成人av在线观看| 久久久久久久久久黄片| x7x7x7水蜜桃| 日韩精品中文字幕看吧| 岛国视频午夜一区免费看| 真人一进一出gif抽搐免费| 精品国内亚洲2022精品成人| 日韩精品青青久久久久久| 深爱激情五月婷婷| 91麻豆av在线| 国产乱人伦免费视频| 国产精品,欧美在线| 午夜精品在线福利| 无限看片的www在线观看| 欧美av亚洲av综合av国产av| 日韩欧美精品免费久久 | 我的老师免费观看完整版| 亚洲内射少妇av| 热99re8久久精品国产| 搡老熟女国产l中国老女人| 亚洲成人精品中文字幕电影| 久久久久九九精品影院| 国产亚洲精品综合一区在线观看| 国产精品久久久人人做人人爽| 午夜福利视频1000在线观看| 一区二区三区国产精品乱码| avwww免费| 中亚洲国语对白在线视频| 制服人妻中文乱码| 亚洲精品亚洲一区二区| 99国产精品一区二区蜜桃av| 精品久久久久久久久久免费视频| 最好的美女福利视频网| 亚洲黑人精品在线| 国产欧美日韩精品一区二区| avwww免费| 国产精华一区二区三区| 人人妻人人看人人澡| 久久国产乱子伦精品免费另类| 夜夜爽天天搞| 天堂网av新在线| 又粗又爽又猛毛片免费看| 在线观看美女被高潮喷水网站 | 日韩欧美在线二视频| 色综合婷婷激情| 欧美bdsm另类| 亚洲不卡免费看| 免费看十八禁软件| 午夜福利在线观看吧| 很黄的视频免费| 欧美成人一区二区免费高清观看| 三级毛片av免费| 一级毛片女人18水好多| 99久久九九国产精品国产免费| 婷婷精品国产亚洲av在线| 日本精品一区二区三区蜜桃| 一个人观看的视频www高清免费观看| 亚洲第一欧美日韩一区二区三区| 成人欧美大片| 999久久久精品免费观看国产| 日韩欧美一区二区三区在线观看| 免费观看人在逋| 久久久久国内视频| 国产成人av教育| 日日摸夜夜添夜夜添小说| 人人妻,人人澡人人爽秒播| 亚洲av第一区精品v没综合| 99久久成人亚洲精品观看| 国产免费一级a男人的天堂| 99国产综合亚洲精品| 欧洲精品卡2卡3卡4卡5卡区| 不卡一级毛片| 亚洲av第一区精品v没综合| 最新美女视频免费是黄的| 久久欧美精品欧美久久欧美| 成人无遮挡网站| 啦啦啦韩国在线观看视频| 免费看a级黄色片| 精品久久久久久久末码| 午夜日韩欧美国产| 一区福利在线观看| 午夜激情欧美在线| 在线天堂最新版资源| 有码 亚洲区| 中出人妻视频一区二区| 精品国产超薄肉色丝袜足j| a级毛片a级免费在线| 色综合欧美亚洲国产小说| 精品国产超薄肉色丝袜足j| 叶爱在线成人免费视频播放| 国产精品一区二区免费欧美| 久久久久亚洲av毛片大全| 俄罗斯特黄特色一大片| 最近最新免费中文字幕在线| 久久香蕉精品热| 日本黄大片高清| 久久精品国产亚洲av香蕉五月| 久久亚洲真实| 欧美国产日韩亚洲一区| 亚洲精品一卡2卡三卡4卡5卡| 国产一区二区在线观看日韩 | 精品乱码久久久久久99久播| 国产精品自产拍在线观看55亚洲| 国产精品 国内视频| 老司机福利观看| 亚洲国产精品合色在线| 美女免费视频网站| 一夜夜www| 国产69精品久久久久777片| 国产熟女xx| 一级a爱片免费观看的视频| 亚洲av一区综合| 中文字幕人妻熟人妻熟丝袜美 | 亚洲av电影不卡..在线观看| 婷婷精品国产亚洲av在线| 久久久久国内视频| 久久久久国产精品人妻aⅴ院| 长腿黑丝高跟| 亚洲不卡免费看| 波多野结衣高清无吗| 嫩草影院入口| 国产成+人综合+亚洲专区| 99热只有精品国产| 亚洲人成网站在线播| 国产高潮美女av| 91久久精品国产一区二区成人 | 五月玫瑰六月丁香| 两人在一起打扑克的视频| 在线观看免费视频日本深夜| 久久久久久久精品吃奶| 亚洲一区二区三区不卡视频| 亚洲内射少妇av| 蜜桃久久精品国产亚洲av| 又粗又爽又猛毛片免费看| 久久精品91无色码中文字幕| 老司机深夜福利视频在线观看| 一二三四社区在线视频社区8| 国产v大片淫在线免费观看| 国产免费一级a男人的天堂| 69av精品久久久久久| 波多野结衣巨乳人妻| 国产欧美日韩一区二区三| 国产中年淑女户外野战色| 成年版毛片免费区| 国产蜜桃级精品一区二区三区| 国产精品爽爽va在线观看网站| 亚洲av成人不卡在线观看播放网| 国产一级毛片七仙女欲春2| 日韩欧美三级三区| 在线观看午夜福利视频| 午夜久久久久精精品| 九九在线视频观看精品| 国产精品免费一区二区三区在线| 亚洲av第一区精品v没综合| 亚洲欧美精品综合久久99| 少妇熟女aⅴ在线视频| 色噜噜av男人的天堂激情| 亚洲精品影视一区二区三区av| 国内久久婷婷六月综合欲色啪| 在线观看免费视频日本深夜| 亚洲国产欧洲综合997久久,| 狂野欧美白嫩少妇大欣赏| 欧美乱码精品一区二区三区| 亚洲成人精品中文字幕电影| 日本 欧美在线| 精品一区二区三区av网在线观看| 精品国产亚洲在线| 国产精品免费一区二区三区在线| 色综合欧美亚洲国产小说| 又粗又爽又猛毛片免费看| 嫁个100分男人电影在线观看| 欧美精品啪啪一区二区三区| 欧美性猛交╳xxx乱大交人| 天堂网av新在线| 国产主播在线观看一区二区| 免费看日本二区| 国产黄片美女视频| 国产成年人精品一区二区| 日韩高清综合在线| aaaaa片日本免费| 真人做人爱边吃奶动态| 午夜福利高清视频| 女生性感内裤真人,穿戴方法视频| av片东京热男人的天堂| 国产精品99久久久久久久久| 国产一区二区在线观看日韩 | 日本五十路高清| 一个人免费在线观看的高清视频| av片东京热男人的天堂| 婷婷亚洲欧美| 一进一出好大好爽视频| 最近在线观看免费完整版| 国产成+人综合+亚洲专区| 国产高清激情床上av| 一本一本综合久久| 精品久久久久久久久久免费视频| 在线观看免费视频日本深夜| 99精品欧美一区二区三区四区| 免费看美女性在线毛片视频| 日本与韩国留学比较| 国产精品爽爽va在线观看网站| 少妇的丰满在线观看| 在线观看舔阴道视频| 日韩 欧美 亚洲 中文字幕| 欧美成人a在线观看| 99久久成人亚洲精品观看| 中文亚洲av片在线观看爽| 欧美黑人欧美精品刺激| 香蕉丝袜av| 在线播放国产精品三级| 亚洲一区二区三区色噜噜| 久久久久久久午夜电影| 国产精品亚洲av一区麻豆| 全区人妻精品视频| 久久久久久国产a免费观看| 中出人妻视频一区二区| 999久久久精品免费观看国产| 男女做爰动态图高潮gif福利片| 色视频www国产| 亚洲精品在线美女| 长腿黑丝高跟| 波多野结衣高清无吗| 热99在线观看视频| 午夜福利在线观看吧| 99热这里只有是精品50| 人人妻人人澡欧美一区二区| 久久香蕉国产精品| 可以在线观看的亚洲视频| 欧美绝顶高潮抽搐喷水| www.色视频.com| 精品一区二区三区视频在线 | 久久久久久久久大av| 天美传媒精品一区二区| 日韩欧美精品v在线| 男女床上黄色一级片免费看| 真人一进一出gif抽搐免费| 两性午夜刺激爽爽歪歪视频在线观看| 欧美黑人欧美精品刺激| 亚洲aⅴ乱码一区二区在线播放| 欧美成人a在线观看| 国内久久婷婷六月综合欲色啪| 女人高潮潮喷娇喘18禁视频| 午夜福利视频1000在线观看| 成年女人毛片免费观看观看9| 午夜两性在线视频| 精品久久久久久,| 欧美xxxx黑人xx丫x性爽| 国产色婷婷99| 亚洲国产精品999在线| 国产成人影院久久av| 老司机深夜福利视频在线观看| 变态另类丝袜制服| 亚洲天堂国产精品一区在线| 色在线成人网| 男插女下体视频免费在线播放| 一本综合久久免费| www.色视频.com| 无人区码免费观看不卡| h日本视频在线播放| 国内毛片毛片毛片毛片毛片| 内地一区二区视频在线| 日韩中文字幕欧美一区二区| 性色av乱码一区二区三区2| 亚洲人成网站高清观看| 精品电影一区二区在线| 91在线精品国自产拍蜜月 | 此物有八面人人有两片| 久久久久国内视频| 亚洲无线观看免费| 国产精品久久久久久精品电影| 操出白浆在线播放| 免费无遮挡裸体视频| 国产一区二区在线av高清观看| 精品久久久久久久久久免费视频| АⅤ资源中文在线天堂| 波多野结衣巨乳人妻| 久久久国产精品麻豆| 国产伦精品一区二区三区四那| 国产成人福利小说| 欧美一级a爱片免费观看看| 丰满人妻一区二区三区视频av | 一区福利在线观看| av黄色大香蕉| 日韩欧美三级三区| 国产激情欧美一区二区| 国产一区二区亚洲精品在线观看| 国产精品野战在线观看| 亚洲性夜色夜夜综合| 在线观看舔阴道视频| 18禁在线播放成人免费| 成人永久免费在线观看视频| 女人十人毛片免费观看3o分钟| 少妇高潮的动态图| 免费人成视频x8x8入口观看| 日本成人三级电影网站| 真人一进一出gif抽搐免费| 国产高潮美女av| 国产精品美女特级片免费视频播放器| 91字幕亚洲| 一级黄片播放器| 最好的美女福利视频网| 午夜福利成人在线免费观看| 他把我摸到了高潮在线观看| 欧美一级a爱片免费观看看| 国产国拍精品亚洲av在线观看 | 丰满的人妻完整版| 高潮久久久久久久久久久不卡| 国产精品一区二区三区四区久久| 一区二区三区国产精品乱码| 免费看美女性在线毛片视频| 老熟妇乱子伦视频在线观看| 国模一区二区三区四区视频| 亚洲精品在线美女| 51国产日韩欧美| 午夜免费成人在线视频| 美女高潮的动态| 3wmmmm亚洲av在线观看| 午夜久久久久精精品| 亚洲18禁久久av| 国产av麻豆久久久久久久| 一二三四社区在线视频社区8| 成人av在线播放网站| 美女 人体艺术 gogo| av黄色大香蕉| 麻豆成人av在线观看| 亚洲熟妇熟女久久| 女人被狂操c到高潮| 波野结衣二区三区在线 | 美女cb高潮喷水在线观看| 国内精品一区二区在线观看| 色综合站精品国产| 人妻丰满熟妇av一区二区三区| 日韩 欧美 亚洲 中文字幕| x7x7x7水蜜桃| 亚洲av五月六月丁香网| 欧美乱码精品一区二区三区| 久久精品夜夜夜夜夜久久蜜豆| 乱人视频在线观看| 久久人妻av系列| 在线观看一区二区三区| 欧美色视频一区免费| 午夜福利高清视频| 1024手机看黄色片| 九九在线视频观看精品| 18禁美女被吸乳视频| 免费看十八禁软件| 久久精品国产99精品国产亚洲性色| 又黄又粗又硬又大视频| 国产高清激情床上av| 久久久久性生活片| 夜夜看夜夜爽夜夜摸| 国产毛片a区久久久久| 精品久久久久久,| 国产成人影院久久av| 免费av不卡在线播放| 男女之事视频高清在线观看| 成人av一区二区三区在线看| 少妇丰满av| 99久久精品国产亚洲精品| 三级国产精品欧美在线观看| 亚洲五月天丁香| 少妇熟女aⅴ在线视频| 久久精品综合一区二区三区| 日本一本二区三区精品| 少妇人妻一区二区三区视频| 国产精品嫩草影院av在线观看 | 免费人成在线观看视频色| 精品人妻1区二区| 午夜精品久久久久久毛片777| 三级男女做爰猛烈吃奶摸视频| 搡老妇女老女人老熟妇| 欧美日本视频| 波多野结衣高清作品| 99久久成人亚洲精品观看| 久久精品国产自在天天线| 性欧美人与动物交配| 此物有八面人人有两片| 女警被强在线播放| 亚洲美女黄片视频| 中文字幕人妻熟人妻熟丝袜美 | 日韩国内少妇激情av| 最近最新免费中文字幕在线| 老熟妇仑乱视频hdxx| 性欧美人与动物交配| 他把我摸到了高潮在线观看| 麻豆一二三区av精品| 性色av乱码一区二区三区2| 亚洲人成网站在线播放欧美日韩| 在线免费观看不下载黄p国产 | 亚洲乱码一区二区免费版| 亚洲不卡免费看| 天堂√8在线中文| 国产亚洲精品一区二区www| 最近最新免费中文字幕在线| 在线观看av片永久免费下载| 亚洲av电影不卡..在线观看| 长腿黑丝高跟| 99国产精品一区二区三区| 高清毛片免费观看视频网站| 欧美又色又爽又黄视频| 成人18禁在线播放| 丰满乱子伦码专区| 黄色日韩在线| 美女 人体艺术 gogo| avwww免费| 脱女人内裤的视频| 国产高清有码在线观看视频| 色哟哟哟哟哟哟| 成年免费大片在线观看| 丰满的人妻完整版| 国产亚洲精品综合一区在线观看| 色精品久久人妻99蜜桃| 嫩草影视91久久| 色av中文字幕| 久久久久久久久久黄片| 成人永久免费在线观看视频| 黄片大片在线免费观看| 国产午夜精品久久久久久一区二区三区 | 真实男女啪啪啪动态图| 欧美性猛交╳xxx乱大交人| 日本成人三级电影网站| aaaaa片日本免费| 丰满的人妻完整版| 亚洲成av人片在线播放无| 国产精品久久视频播放| 久久欧美精品欧美久久欧美| www.熟女人妻精品国产| 国产一区二区三区在线臀色熟女| 久久国产精品影院| 日本撒尿小便嘘嘘汇集6| 一进一出好大好爽视频| 韩国av一区二区三区四区| 久久天躁狠狠躁夜夜2o2o| 精品人妻偷拍中文字幕| 日本在线视频免费播放| 国产一区二区三区在线臀色熟女| 女同久久另类99精品国产91| e午夜精品久久久久久久| 久久久成人免费电影| 国产伦精品一区二区三区四那| 国产精品久久久久久人妻精品电影| 在线天堂最新版资源| 成人性生交大片免费视频hd| 久久精品人妻少妇| 欧美色视频一区免费| 午夜福利成人在线免费观看| www日本黄色视频网| 首页视频小说图片口味搜索| 久久欧美精品欧美久久欧美| 欧美色欧美亚洲另类二区| 亚洲精品亚洲一区二区| 国产97色在线日韩免费| 亚洲精品成人久久久久久| 又爽又黄无遮挡网站| av天堂在线播放| 女警被强在线播放| 亚洲精品亚洲一区二区| 免费在线观看亚洲国产| 亚洲精品一区av在线观看| 免费在线观看亚洲国产| 精品人妻1区二区| 免费在线观看成人毛片| 婷婷精品国产亚洲av在线| 久久久国产成人精品二区| 一级a爱片免费观看的视频| 看免费av毛片| 天天躁日日操中文字幕| av中文乱码字幕在线| 制服人妻中文乱码| 天美传媒精品一区二区| 成人av一区二区三区在线看| 蜜桃久久精品国产亚洲av| 综合色av麻豆| 女同久久另类99精品国产91| 又爽又黄无遮挡网站| 天堂√8在线中文| 免费无遮挡裸体视频| 亚洲人成伊人成综合网2020| 日韩欧美三级三区| 国内精品一区二区在线观看| 一进一出抽搐动态| 啦啦啦免费观看视频1| 欧美大码av| 有码 亚洲区| 夜夜夜夜夜久久久久| 国产精品一区二区免费欧美| 99热只有精品国产| 可以在线观看毛片的网站| 久久香蕉国产精品| 亚洲国产欧美网| 69人妻影院| 手机成人av网站| 中国美女看黄片| 国产亚洲精品久久久久久毛片| 99riav亚洲国产免费| 大型黄色视频在线免费观看| 免费看日本二区| 波多野结衣高清无吗| 免费在线观看成人毛片| 久久精品国产自在天天线| 校园春色视频在线观看| 男女午夜视频在线观看| 好男人在线观看高清免费视频| 三级国产精品欧美在线观看| 亚洲精华国产精华精| 亚洲 国产 在线| 日韩欧美在线二视频| 亚洲av日韩精品久久久久久密| 国语自产精品视频在线第100页| 一本一本综合久久| 日韩成人在线观看一区二区三区| 内地一区二区视频在线| 成熟少妇高潮喷水视频| 丰满的人妻完整版| 国产激情偷乱视频一区二区| 岛国在线免费视频观看| 一区二区三区高清视频在线| 欧美3d第一页| 香蕉av资源在线| 美女被艹到高潮喷水动态|