流体力学第二版课后作业答案

1-14drrrrrdrrdydudArdFdM32023224203ddrrdMMdA1-18由1-14的结果得2.791023.096046.09014.31044003032323424424nddMN·m1-22由2642322RRgh得4622223RRhg其中sin1cosR则22sin13sin21cos2RhgR2-12)()()(112342hHghhghhgppOHHgHga)5.15.3(8.91000)5.15.2(8.913600)0.13.2(8.913600105386944Pa2-21设油的密度为96.11745428.328.38.9100083.0ABcABABAghFN5644816.14836424.224.28.9100024.28.38.9830221ABcBCOHBCABBCBCBCAghAghFFF16.204812N12.322267BCABABCFFFN对A点取矩32211DBCDBCDABDABCyFyFyFyF12.322267)324.28.3(56448)24.28.3(16.148364)328.3(96.117454Dy171.4m（距A点）2-237.4124105842.19.0)60sin29.0(9800hhAghFc总压力F的作用点到A点的距离)45.01547.1(1281.045.09.02.1)29.060sin(129.02.145.029.03hhAyIyccx由yFG3.0整理得0014.22558968.83602262.659952hh（提示aacbbx242）解得：877.0hm2-24图示法：hFyFyF322221整理得421yy又21211hlAA所以2231l1l于是414.123211lym586.2412yym2-29C点的测压管水面的距离673.99800101325196120gppHam)13222673.9(114.3980032)2(232RhHRggVFFpz37.246kN2-31)25.014.33215.014.341(9800)3241(3232RHDggVFpz7.1602N7.40041zFFN3-13gVgpzgVgpzBBBAAA2222其中：4.2AVm/s；4.51.015.04.22222BAABddVVm/s；2.1BAzzm；5.1gpAm代入上式得506.18.924.54.25.12.122gpBm3-2622.014.33600226442211dqVvm/s81.014.33600226442222dqVvm/sgVgpzgVgpz2222222111其中21zz则1702)82(10002000002222222112VVppkPa在水平面内建立平面坐标系xoy，并取缓变流截面1-1，2-2及管道边界为控制面。作用在控制面内液体的外力有：弯管对水流的作用力F，作用在1-1和2-2截面的动水压力11Ap和22Ap，控制面内水体的重力。由于重力铅直向下，在水平面的x轴和y轴方向分量为零；不计水流阻力时，动量修正系数121。所以沿x轴和y轴方向建立动量方程得：yFFy0xFxx轴：xvFApuuq1112)(代入数据：xF42.014.3200000)20(360022610002解得56.6405xFNy轴：yvFApvvq2212)(代入数据：yF41.014.3170000)08(360022610002解得7.1836yFN68.666322yxFFFN合力与x方向的夹角为：1656.64057.1836arctgFFarctgxy4-1（1）0)00(21)(21yuxvz无旋（2）)cossin(2)(21xyxxyykyuxvz有旋（3）0)11(21)(21zvywx0)11(21)(21xwzuy0)11(21)(21yuxvz无旋（4）21)10(21)(21zvywx21)10(21)(21xwzuy21)10(21)(21yuxvz有旋4-2（1）0404yyyvxu不存在流函数02)48(21)(21xxxyuxvz不存在势函数（2）改为222yxxu0)22(21)(21yyyuxvz存在势函数0)22()22(xxyvxu存在流函数求势函数222yxxux积分：)(31223yfxyxx——————（a）yxyvyfxyy22)(2yyf2)(则Cyyf2)(代入（a）式得Cyxyxx222331求流函数222yxxuy积分：)(31232xfyxyyx——————（b）yxyvxfyxyx22)(220)(xf则Cxf)(代入（b）式得Cyxyyx323124-6（1）byaxxu2aybxyv2byaxuy2积分：)(2122xfbyaxy——————（a）aybxvxfayx2)(2即bxxf)(则Cxbxf22)(代入（a）式得Cbyaxybx2221221（2）224)2(2)2(babaybxabyaxyuvxuuax022)2)(2()2(ababaaybxbbyaxyvvxvuay6-6936.125.014.3095.04422dqVvm/s2000490751025.0963.1Re5Vd紊流001.025025.0d查莫迪图：024.05.58.92936.125.0300024.0222gVdlhfmH2O6-8gVdlhf22757.320025.03.02.18.922lgdhVfm/s25.42.114.341757.34122dVqvm3/s6-14（1）36.0025.0105.42000Re6maxdVm/s(2)423.08.9236.0025.0502000642Re6422gVdlhfm原油柱(3)41018.5504025.08.9423.02lgrhf