吴持恭水力学习题答案.doc

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1、习题答案0绪论0.1ρ＝816.33kg/m30.2当y=0.25H时当y=0.5H时0.4f=g0.5h的量纲为[L]0.6Ff＝184N0.7K=1.96×108N/m2dp=1.96×105N/m21水静力学1.1Pc=107.4KN/m2h=0.959m1.2PB-PA=0.52KN/m2PAK=5.89KN/m2PBK=5.37KN/m21.3h1=2.86mh2=2.14m侧测压管油面与桶底的垂距为5m，外侧测压管油面与桶底的垂距为4.28m。1.4Pc=27.439KN/m21.5PM=750.68hKN/m21.6P2-p1=218.05N/m2

2、1.7=1.8P=29.53KN方向向下垂直底板P＝01.9W=34.3rad/sWmax=48.5rad/s1.10a=1.12当下游无水Px=3312.4KN(→)P2=862.4KN(↓)当下游有水Px=3136KN(→)P2=950.6KN(↓)1.13T=142.9KN1.14当h3=0时T=131.56KN当h3=h2=1.73m时T＝63.7KN1.150－0转轴距闸底的距离应为1.2m1.16P=4.33KNLD=2.256m(压力中心距水面的距离)1.17P=567.24KN1.19P＝45.54KN总压力与水平方向夹角＝14º28´1.20P

3、x=353KNPz=46.18KN方向向下1.21H=3m1.22=1.0cm1.23F=25.87KN(←)2液体运动的流束理论2.1Q=211.95cm3/sV＝7.5cm/s2.2hw=3.16m2.3=2.35m2.4PK=63.8KN/m22.5Q=0.00393m3/s2.6Q=0.0611m3/s2.7=0.9852.8Q=0.058m3/s2.9S点相对压强为－4.9N／cm2，绝对压强为4.9N/cm22.10V3=9.9m/sQ=0.396m3/s2.11Rx=391.715KN(→)2.12R=3.567KN合力与水平方向夹角＝37º8´2

4、.13Rx=98.35KN(→)2.14Rx=2988.27KN(→)2.15Rx=1.017KN(←)2.16Rx=153.26KN(→)2.17=22.18F=2.19Q=H2.52.20F=CdL22.212.22Q1=cos2.23R=2145KN=54º68´2.24m=3.12kg2.25T充＝24分34秒T放＝23分10秒3.液流型态及水头损失3.1d增加，Re减小3.2Re=198019.8>2000紊流3.3Re=64554>500紊流3.43.5当3.6Q/s3.7当Q=5000cm3/s时，Re=19450紊流光滑管区当Q＝20000cm3

5、/s时Re=78200紊流过渡粗糙区当Q＝200000cm3/s时Re=780000紊流粗糙区若l＝100m时Q＝5000cm3/s时hf=0.006mQ=2000cm3/s时hf=0.09mQ＝200000cm3/s时hf=7.85m3.8＝0.0423.9n=0.0113.10=0.293.11Q=0.004m3/s3.12h=0.158m3.13Z=11.1m3.14=24.74有压管中的恒定流4.1当n=0.012时Q=6.51m3/s当n=0.013时Q=6.7m3/s当n=0.014时Q=6.3m3/s4.2当n=0.0125时Q=0.68m3/s当

6、n=0.011时Q=0.74m3/s当n=0.014时Q=0.62m3/s4.3Q=0.0268m3/sZ=0.82m4.4当n=0.011时H=7.61m当n=0.012时H=7.0m4.5Ht=30.331m4.6n取0.012Q=0.5m3/sh=5.1m4.7n取0.0125时H＝21.5m水柱高4.8Q1=29.3L/sQ2=30.7L/s=135.21m4.9H=0.9m4.10Q2=0.17m3/sQ3=0.468m3/s4.11Q1=0.7m3/sQ2=0.37m3/sQ3=0.33m3/s4.12H1=2.8m4.13Q=0.0105m3/sP

7、=10.57KN/m24.14Q1=0.157Q25明渠恒定均匀流5.1V=1.32m/sQ=0.65m3/s5.2Q=20.3m3/s5.3Q=241.3m3/s5.4h=2.34m5.5h=1.25m5.6b=3.2m5.7b=71mV=1.5m/s大于V不冲＝1.41m/s故不满足不冲流速的要求5.8当n=0.011时i=0.0026=51.76m当n=0.012时i=0.0031当n=0.013时i=0.0036当n=0.014时i=0.00425.9i=1/3000V=1.63m/s

8、0.025时b=7.28