习题课第一章

1、11A-A22解:槽水面为截面1-1，管路出口内侧截面取2-2，出口管中心线为基准水平面+ u12 + p1 / + We= gZ2 + u22 + p2 / + hfgZ1We = 0;p1 = p2 = po ;Z1=8-2=6m, Z2=0m; u1= 0, u2u; hf = 6.5u29.8x6 = (6.5+0.5)u2=8m2m2水的流量，m3/hVsd2 u(0.108-2x0.004)2 x2.9= 0.02278m3/s = 82m3/h11A-A228m2m解： 取贮槽水面为截面1-1，排水管内侧截面2-2，取贮槽水面为基准水平面gZ1 + u12 + p1 / + We

2、= gZ2We = ?p1 = 0，p2 = 98.07x103Pa(表）+ p2 / + hf，1，2+ u2222Z1=0m, Z2=14mu1= 0, u2 = uhf = 2u2 + 10u21114m1.5m截面为3-3取泵的gZ1 + u12 + p1 / + We= gZ3+ p3 / + hf，1+ u32Z1=0m, Z2=1.5mu1= 0, u3 = uhf = 2u2221114m1.5mWe = 0p1 = 0，p3 = -24.66x103Pa(表）We= 235.27 + 12.5 u22u = 2m/s解：选取管中心线为基准水平面，垂直于管路的左右测量处为截面1

3、-1和2-2gZ1 + u12 + p1 / + We= gZ2 + u22 + p2 / + hf4ws4x10800u = 2.95m/s12d3600 xx0.0362x1031解：低位槽溶液液面为基准水平面亦，为亦为亦为截1面-1截面截，槽的液面为截2面-2截面截面gZ1 + u12 + p1 / + We= gZ2 + u22+ p2 / +hfWe = ？p1 = -26.7x103Pa (表），p2= 0Z1=0m, Z2=15mu1= u2 = 02211We= 172.03 + hfli + leu2+ hf = (d24ws4x2x104u= 1.43m/sd23600 x

4、x0.0682x1073du0.068x1.43x1073Re = 1.66x1056.3x10-4 = 0.3 /d= 0.3/68 =0.0044查表 = 0.029l = 50mle = 0.45x2+2.1x5 =11.4m = 0.5+1+4 =5.5li + leu2+ 2hf = (d+1.432+ = (0.02920.068=32.30J/kg解：选鼓风机管中心线为基准水平面，垂直于此中心线为截面1-1，放空出口处为截面2-2+ u12 + p1 / + We= gZ2 + u22 + p2 / +hfgZ1Z1=0m, Z2=20m= gh=103 x9.8x0.03=29

5、4Pa (表）p1We= -72.98 + hfli + leu2+ hf = (+ Pf /d2duRe =We= -72.98 + hfli + leu2+ 2hf = (+ Pf /d =0.019d=250mm（1）当闸阀关闭时，测得R=600mm、h=1500mm；当闸阀部分开启时，测得R=400mm、h=1400mm。摩擦系数可取为0.025，管路处的局部阻力系数取为0.5。问每小时从管中流出若干m3的水+ u12 + p1 / = gZ2 + u22 + p2 / +Z1=？, Z2=0p1 = 0，p2 = ？u1= 0，u2=？hfgZ1解：d = 100mm当闸阀关闭时，测得R=600mm、h=1500mm215m20mp =水银gR 水gh= (13.6x0.6-1x1.5)x103x9.8=65268Pa2hR11=水gZ1p =65268Pa（2）当闸阀全开时，U管压差计测压处的静压强为若干若干若P表a干（压表）压。表）压。）闸。阀全开时约le/为d 约为摩约1擦5为，系摩擦系摩擦系数仍可取数仍可取数0.0仍25可. 取解：当闸阀全开在时截，面在截和面截在1-面1截和面截面和3-3截之面间列方程方程方程gZ1 + u12 + p1 /+hf= gZ3 + u32 + p3 /Z1=6.66m, Z3=0p1 = 0，p3 = 0u1= 0