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1、机械能转化演示实验五、数据记录与分析温度：25°C 管路内经di=30mm 节流件变截面管内径d2=15mmh4和h5之间管径长L=61cm表1原始数据记录V( L/h)h1(cm)h2(cm)h3(cm)h4(cm)h5(cm)h6(cm)400105.5102.4104.136.936.537.3520105.3101.9103.936.435.936.6640104.899.7102.535.134.435.4760104.598.2102.234.433.534.5880104.196.1101.233.232.633.61000103.492.6100.131.330.53
2、1.61120103.390.599.430.229.830.61240102.787.697.828.728.029.11. hl和h2分析表2 h1、h2变截面连续性方程序号V(L/h)h1(cm)h2(cm)流速u*m/s)流速 U2（m/s） 2“ -4U1d1 x10 2“-4U2d2 x101400105.5102.40.160.801.411.792520105.3101.90.200.841.841.893640104.899.70.251.032.262.324760104.598.20.301.152.692.595880104.196.10.351.303.112.926
3、1000103.492.60.391.513.543.3971120103.390.50.441.643.963.7081240102.787.60.491.794.394.02分析：流体为均质、不可压缩流体，连续性方程成立 数据处理实例：以第一组数据为例Ui2900冗 d4001000 900 二0. 032=0. 16由22PiUi _P2U2為2g一7g2gu2 = 2g (hi _h2)u： = 2 9.8 (105. 5 - 102.4)10-20.162 = 0.80据式(5)知：u1d1 0. 160 . 032 = 1.4110224u2d20. 80 0. 0152 = 1.
4、79 102 2则 u": u2d12. hl和h3的分析表3 hl、h3流体经节流件后压头损失关系骨口. 序号V(L/h)流速U1（mh1(cm)h3(cm)压头损失hf（ cm）14000.16105.5104.11.425200.20105.3103.91.436400.25104.8102.52.347600.30104.5102.22.358800.35104.1101.22.9610000.39103.4100.13.3711200.44103.399.43.9812400.49102.797.84.950S.04.030201 (100D ID.6QSI hl. h氛帝
5、怖经节流件话珏丢拯餐黄系分析：流速增大，压头损失增大，压头损失和速 度的平方成正比数据处理实例：以第一组数据为例 流速计算同1中的相同=1.4cmhf = hl - h3 = 105.5 - 104.1验报告纸3. h3和h4的分析04©OR0.40心丽表4 h3、h4流体经弯头和流量计件后压头损失和位能变化关系骨口. 序号V(L/h)流速u1（mh3(cm)h4(cm)位能差（cm）14000.16104.136.967.225200.20103.936.467.536400.25102.535.167.447600.30102.234.467.858800.35101.233.2
6、68.0610000.39100.131.368.8711200.4499.430.269.2812400.4997.828.769.17.0|2流体经弯丟和流李计件后斥氓掘朱和位能变化養垂|分析：流体经3到4处，受弯头和转子流量计及位能的影响且随流量的增大，单 管压力计3和4的读数差变大，流体局部阻力导致的能头损失增大。数据处理实例：以第一组数据为例流速计算同1中的相同位能差 二 h3 - h4 = 104.1 - 36.9 = 67.2cm4. h4和h5的分析表5 h4、h5直管段雷诺数和流体阻力系数关系骨口. 序号V(L/h)流速m(m/s)h4(cm)h5(cm)阻力系数入Rehf1
7、4000.1636.936.50.165267.110.425200.2036.435.90.126847.240.536400.2535.134.40.118427.370.747600.3034.433.50.1010007.500.958800.3533.532.60.0711587.640.9610000.3931.330.50.0513167.770.8711200.4430.229.80.0214747.900.5812400.4928.728.00.0316328.030.7o n D D o o O4/MN)6»000民000 ldOX) 13,CX»14,
8、 DOO14.00019.000图3宜育段需诺数和流体阳力系曲关系分析：Re足够大时，入与Re无关，只与流体流速平方成正比数据处理实例：以第一组数据为例（25C,水的粘度卩=0.8937x103pas）流速计算同1中的相同H = h4 - h5 = 36.9 - 36.9 = 0cmR?du、0.03 0.16 竽2 ,267.112hf dgu2L 10,0.893710-0. 1620.40. 039.80. 162 0.61 10,5. h5和h6的分析表6 h5、h6单管压力计h5处中心点速度骨口. 序号V(L/h)流速m(m/s)h5(cm)h6(cm)A hu (m/s)平均u (m/s)14000.1636.537.30.80.400.4325200.2035.936.60.70.3736400.2534.435.41.00.4447600.3033.534.51.00.4458800.3532.633.61.00.44610000.3930.531.61.10.46711200.4429.830.60.80.40812400.4928.029.11.10.46数据处理实例：以第一组数据为例流速计算同1中的相同2Uc2gUc二（2 ：hg）1/220. 89.8100=0. 40m/s