- Comparison With Calculation Here The Measured Head Losses Are Compared With Values Calculated Mathematically For The C 1 (47.56 KiB) Viewed 40 times
Comparison with calculation Here, the measured head losses are compared with values calculated mathematically. For the calculation, the wall roughness of the pipe used and the kinematic viscosity of the water must be known (see Chapter 6.2, Page 82). For this pipe section (PVC pipe, technically smooth), a wall roughness of k= 0,001 mm is selected. Head loss h in m 0,01 0,02 0,04 0.06 0,12 0,16 0,25 Volumetric flow V in min 4,6 7,06 10,53 15 19,35 24 30 Volumetric flow in ms 7,7-10 11,7-10 17,7-10 25,1-10 32.3-10 40,1-10 50,1-10 Flow speed in m/s 0,34 0,52 0.77 1,1 1,42 1,76 2,2 Reynolds num ber Re 5756 8805 13038 18625,40 24044 29801 37251 Pipe friction coef- 0,03632 0,033 0,030 0,027 0,025 0,024 0,023 ficient according to Blasius Calculated head loss h 0.00996 0.021 0,04206 0,078 0,121 0,178 0,26700 Variance in % -0,18 7,01 6.06 -2,05 0.76 11,44 6.6 Tab. 4.3 Measuring section II, PVC pipe 20 x 1,5 Experiment 4 straight: d-20x1,5mm, length: 800mm, PVC Measuring section II -0.018 PVC pipe 20 x 1,5 Steps (for two sectid0-6 &/m2/s Measure flow to obtain v Calculate head loss&pressure drop Compare with measured head loss Calculate Re for 2 cases lamda From mody Head loss h in m Volumetric flow V in Umin Volumetric flow V in mys Flow speed in m/s Reynolds' num- ber Re Pipe friction coef- ficient according to Blasius A Calculated head loss h Variance in % The kinematic viscosity -1.004