機(jī)械能轉(zhuǎn)化演示實(shí)驗(yàn)

1、五、數(shù)據(jù)記錄與分析溫度：25°C 管路內(nèi)經(jīng)di=30mm 節(jié)流件變截面管內(nèi)徑d2=15mmh4和h5之間管徑長L=61cm表1原始數(shù)據(jù)記錄V( L/h)h1(cm)h2(cm)h3(cm)h4(cm)h5(cm)h6(cm)400105.5102.4104.136.936.537.3520105.3101.9103.936.435.936.6640104.899.7102.535.134.435.4760104.598.2102.234.433.534.5880104.196.1101.233.232.633.61000103.492.6100.131.330.531.6112010

2、3.390.599.430.229.830.61240102.787.697.828.728.029.11 . h1和h2分析表2 h1、h2變截面連續(xù)性方程骨口. 序號V(L/h)h1(cm)h2(cm)流速U1（m流速 U2（m/s） 2“ -4U1d1 x10 2“ -4U2d2 x101400105.5102.40.160.801.411.792520105.3101.90.200.841.841.893640104.899.70.251.032.262.324760104.598.20.301.152.692.595880104.196.10.351.303.112.92610001

3、03.492.60.391.513.543.3971120103.390.50.441.643.963.7081240102.787.60.491.794.394.02分析：流體為均質(zhì)、不可壓縮流體，連續(xù)性方程成立 數(shù)據(jù)處理實(shí)例：以第一組數(shù)據(jù)為例VUl 900nd 240010009000. 0320. 162 2PlU1P2U2I 由 0,200-40Q 仝g2gg2gU22g(h1h2)u1、29. 8 (105.5102. 4)10 20. 1620. 80據(jù)式（5）知：2u1d10.160. 0321.4110 42U2d20.800. 01521. 7910 4則 u1d122口2小

4、12. hl和h3的分析骨口. 序號V(L/h)流速U1 （mh1(cm)h3(cm)壓頭損失hf（ cm）14000.16105.5104.11.425200.20105.3103.91.436400.25104.8102.52.347600.30104.5102.22.358800.35104.1101.22.9610000.39103.4100.13.3711200.44103.399.43.9812400.49102.797.84.9表3 hl、h3流體經(jīng)節(jié)流件后壓頭損失關(guān)系5X9504jO3.02jO10OjOIS1 hl.疵疏淬經(jīng)韋硫件后圧頭損先關(guān)系分析：流速增大，壓頭損失增大，壓

5、頭損失和速度的平方成正比 數(shù)據(jù)處理實(shí)例：以第一組數(shù)據(jù)為例流速計(jì)算同1中的相同hf = h1 - h3 = 105.5 - 104.1= 1.4cm3. h3和h4的分析表4 h3、h4流體經(jīng)彎頭和流量計(jì)件后壓頭損失和位能變化關(guān)系骨口. 序號V(L/h)流速U1 （mh3(cm)h4(cm)位能差（cm）14000.16104.136.967.225200.20103.936.467.536400.25102.535.167.447600.30102.234.467.858800.35101.233.268.0610000.39100.131.368.8711200.4499.430.269.2

6、812400.4997.828.769.16D5S7.00400,0Q 加0.40Q犧。嗣圏7流體經(jīng)彎蚤和浦盤計(jì)件后圧丟掏朱和悅施譽(yù)化美系|分析：流體經(jīng)3到4處，受彎頭和轉(zhuǎn)子流量計(jì)及位能的影響且隨流量的增大, 單管壓力計(jì)3和4的讀數(shù)差變大，流體局部阻力導(dǎo)致的能頭損失增大。 數(shù)據(jù)處理實(shí)例：以第一組數(shù)據(jù)為例流速計(jì)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直管段雷諾數(shù)和流體阻力系數(shù)關(guān)系骨口. 序號V(L/h)流速 U1（m/s）h4(cm)h5(cm)阻力系數(shù)入Rehf14000.1636.936.50.165267

7、.110.425200.2036.435.90.126847.240.536400.2535.134.40.118427.370.747600.3034.433.50.1010007.500.958800.3533.532.60.0711587.640.9610000.3931.330.50.0513167.770.8711200.4430.229.80.0214747.900.5812400.4928.728.00.0316328.030.7分析：Re足夠大時，入與Re無關(guān)，只與流體流速平方成正比數(shù)據(jù)處理實(shí)例：以第一組數(shù)據(jù)為例（25C，水的粘度卩=0.8937x10-3pas）流速計(jì)算同1中

8、的相同Hf = h4 - h5 = 36.9 - 36.9 = 0cmRedu0.03 °16 誓 25267.110. 893710 32hfdg20.40.039. 8u2L100. 1620. 61 10 20. 165. h5和h6的分析表6 h5、h6單管壓力計(jì)h5處中心點(diǎn)速度骨口. 序號V(L/h)流速 U1（m/s）h5(cm)h6(cm)hu (m/s)平均u (m/s)14000.1636.537.30.80.4025200.2035.936.60.70.3736400.2534.435.41.00.4447600.3033.534.51.00.440.4358800.3532.633.61.00.44610000.3930.531.61.10