工程流体力学闻建龙课后答案部分

1、工程流体力学闻建龙课后答案部分22021/1/432021/1/442021/1/41233m9800N601m2m1mbGhhh宽，门重，2-8 矩形闸门，如图所示。求：（1）下游无水时的启门力 （2）下游有水时的启门力BA2hCDchy3hx( )O xcyDyL0y1hT解：（1）下游无水时的启门力根据题意，可列关于A点的力矩平衡方程 0cos()cos 2 DLLyyTFGFG （2）下游有水时的启门力0220cos()cos( )2DDGLLyyyFyTF52021/1/42120133244 3/sin2/sin60=2.309433 / 23(/ 2)=(12/ 2)23 2.3

2、0946.9282g1000 9.8 2 6.9282=135792.72/sin1/sin601.1547/sin2/sin2.30943 2.30943.07921212cccccxDcLhhhhAbLFh AyhyhbLIyy （N ）03.07922.30942.501852.3094 6.9282()135792.72 (2.50185 1.1547)9800163324.84cos22.3094/ 22cxcDIy AFyyGTL0cos()cos 2 DLLyyTFGBA2hCDchy3hx( )O xcyDyL0y1hTFG62021/1/4BA2hCDchy3hx( )O x

3、cyDyL0y1hTG0220cos()cos( )2DDGLLyyyFyTF23233200221gg1000 9.8222131000 9.82.3094=16974.09(N)22225122 3236()5cos2cos65163324.913876 cos5163324.9138716974.09135034.76387(N)3cDDhbLFh AALLLyyLFyyFGTF72021/1/4ddddxxxxxyyyyyxyvvvvvvttxyvvvvvvttxy 222d(2 )() 2dd(2)(2 )()( 1)dxyvxxtytxtyttvxtyxtytxtytt d(2 )

4、2()dd(2)(2 )422()dxyvxxyxytvxxyxyyxtxy 1t 1,2xydddd46xyvtvt dddd46xyvtvt 2216362 13xyaaa 82021/1/4dddxyxytvvd1 (1)dd (2)dxytytt 2212ytC20C 212yt 2d11d2xtt3116xttC 10C 321612xttyt 2329212180 xyyy-5000-4000-3000-2000-100000100200300400500yx92021/1/4dd1xyyt 1ddyyt x （）212yytxC0C 212yyx2220 xyy -1200-10

5、00-800-600-400-200001020304050yx102021/1/414.8m/s9.135m26.073m22 3.06mBBbAAAABBBABwABAvvAApvHzggBpvHzggHHABhHH 解解： ）断断面面 的的总总能能量量为为：断断面面 的的总总能能量量为为：）水水由由 流流向向水水头头损损失失112021/1/4v1v2平 面 图Q2Q ,vQ1yx0sinxRQv 1 1220cosQ vQ vQv （）12QAvQQ 3132120.173(kN)0.03(m /s)0.01(m /s):3:1xRQQQQ 122021/1/4221122v dv d

6、 xy22212221752312.94(m/s)100dvvd2211221222PvPvzzgggg2222521110002312.941.808 10 (Pa)222vvPg ( () ) 211121vxxxvyyyqvvP AFqvvF 132021/1/4 211121vxxxvyyyqvvP AFqvvF 25221221000230.075cos301.808 100.1441000230.075sin3004xyvvFvF 710.6 (N)1168.5 (N)xyFF 221367.6(N)xyFFF 142021/1/4mpFrFr 22ggpmm mp pvvll 或

7、或ggmp 因因2212pmvlmpvvkkll则则，即即1212mltlpltkkktk121460 min1225mplttk （）152021/1/4Re( , ,)f v L Lv 、 、1111ReaaL vL v ，1111311113111130LLTML10031LLTMLML T11aa （） （）（）（）1110,0,01,1,1 RefLv 162021/1/4621 10 m /s 326444 4 10Re50929.63.14 100232.10vvqdqvddd （湍湍流流）36150 1044 4 10Re339.533.140.12320vqd （层层流流）1

8、72021/1/422g2gg2gAAABBBABfpvpvzzh ABABABzzvvv ，= = ，取取2g2gABfppL vhd 0.250.3164Re 182021/1/42220.2520.250.250.250.251.750.251.750.250.251.751.251.2524.750.31640.31640.31642gRe2g2g2g40.31640.31640.024662g2gfvvL vL vL vL vhddddvddvqqLLvLdddd 0.251.7560.251.754.754.754.75100 100.0160.035990.024660.0246

9、6500=gvABqppLddd （）4.7555g0.03599930 9.80.035993 102 1(00.003280.3 m)ABdppd 64Re4 0.0163.14100 100.2323679.405052vqvdd （）（层层流流）192021/1/422g2gg2gAAABBBABfpvpvzzh ABABABzzvvv ，= = ，取取2g2gABfppL vhd 64Re 202021/1/422222246432322gRe2ggg432128ggfvvL vL vL vLhvvdddddqqLLddd 4128ggvABqppLd 46554128128 930

10、 100 100.0165003.143 102 103.03287 100(m).13197vABqdLppd 62320vqvdd （湍湍流流）232021/1/420.251.754.7520.251.7524.75460.251.7524.7541.752410.02466280.024661080.02466600.520.2g 0.297.78406.21vvvvvvvvqqzLdgdqqLdg dqqqq 弯弯阀阀弯弯阀阀（）（）（）（）2222fil vvzhhdgg弯弯阀阀+ +（）0.250.3164Re 0.251.754.750.02466vfqhLd 21.75406.2197.7830vvqq 30.07096(m /s)vq 64Re4 0.070963.14 100.23245192074vqvdd （湍湍流流）242021/1/42222fil vvzhhdgg弯弯阀阀+ +（）223110.0143753.73.7 0.22lg2lg0.05 10d 3/0.05 10/ 0.20.00025d 2222224242412286080.0143750.52 g0.2 g352.526vvvvqlvlzdgdgdqqldddq 弯弯阀阀弯弯阀阀弯弯阀阀23352.526vq