1 2 -2 解:由公式得: 2 -3 解: 2 -8 解:由连续性方程可得 1122v Av Aq 221111[ ()() ]22Ddqv 从而可得 10 . 1/vms 又因为 12210.036/v Avm sA 222222[ ()() ]23.78 / min22DdqvL 2 -9 解:由题可知油液在钢管中处于层流状态 临界2320eR 因为ev dR 2 3 2 04 01 8 5 6/1 . 8 5 6/50eR vvmm sm sd 62 5 01 01 . 8 5 62 1 . 8 5/ m i n4qv AL 6232 109000.0288/6.317.314.6N s mEEE22208008020202060202020260206.317.3172.469/ ,23.785/,(1)(160)1 600.3280.0112(140)1 401 400.01120.5520.5520.552 72.46940/tEEmmsmmstmms 2 2 -1 0 解:因为不计油液流动的能量损失 由图可得 2211221122pvpv 1122v Av A 322622230 / min4 30 10/1.59/60 2010204qLvm sm sAmm 3126130 10425.5/60510qvm sA 22221212900()(25.51.59 )2914740.2922ppvvPaPaMPa 2 -1 1 解:对油箱液面与泵入口处列伯努利方程,以油箱液面为基准面 21222vHg2gpp 真空度: 2 -1 2 解:对油箱液面与泵入口处列伯努利方程,以油箱液面为基准面 222v1223vgH2g2 0.85900 9.8(0.4)2 9.84.18 10ppppa 2211 1222331222422244 10 (/ )0,2.04(/ )0.025( )2.04 0.02535923201.42 10 (/ )2weppvpvghqmsvvm sdmv dRms其中:222e85 2.51063232020 10275750.07R1063ev dR层流2211 122 11211322220,04 25 1085/3.14 2.560pvpvhhggggvhQvcm sA 3 2 -1 3 解:3122144 18 10382/3.14 160Qvcm sd 3222044 18 101062/3.140.660Qvcm sd() 判断流态: 11382 1191023200.2ev dRv层流 021 0 6 20 . 63 1 8 62 3 2 00.2ev dRv紊流 阻力系数: 0393.0191075R75...