Schemat stanowiska
Wzory wyjściowe i wynikowe
Uogólnione równanie Bernoulliego:
$$z_{1} + \frac{p_{1}}{\text{ρg}} + \alpha_{1}\frac{v_{1}^{2}}{2g} = z_{2} + \frac{p_{2}}{\text{ρg}} + \alpha_{2}\frac{v_{2}^{2}}{2g} + h_{1 - 2}^{s}$$
Wysokość energii rozporządzalnej H:
$$H = z + \frac{p}{\text{ρg}} + \alpha\frac{v^{2}}{2g}$$
H1 = H2 + h1 − 2s
Straty energetyczne:
$$h_{1 - 2}^{s} = h_{1 - 2}^{\text{sl}} + h_{1 - 2}^{\text{sm}} = \lambda\frac{l}{d}\frac{v^{2}}{2g} + \xi\frac{v^{2}}{2g}$$
Przykładowe obliczenia
$$\nu = \frac{1}{556406,7 + 19689t + 124,6096t^{2} - 0,3783792t^{3}} = \frac{1}{556406,7 + 19689 \bullet 12 + 124,6096 \bullet 12^{2} - 0,3783792 \bullet 12^{3}} = 1,23 \bullet 10^{- 6}\ m^{2}/s$$
$$v_{1} = \frac{4q_{v}}{\pi d_{1}^{2}} = \frac{4 \bullet \frac{190}{1000 \bullet 3600}}{\pi \bullet {0,0123}^{2}} = 0,444\ m/s$$
$$\text{Re}_{1} = \frac{v_{1}d_{1}}{\nu} = \frac{0,444 \bullet 0,0123}{1,23 \bullet 10^{- 6}} = 4425$$
$$\lambda_{1} = \frac{0,3164}{\sqrt[4]{\text{Re}_{1}}} = \frac{0,3164}{\sqrt[4]{4425}} = 0,0388$$
$$h_{2 - 3}^{\text{sl}} = \lambda_{1}\frac{l_{1}}{d_{1}}\frac{v_{1}^{2}}{2g} = 0,0388 \bullet \frac{0,615}{0,0123} \bullet \frac{{0,444}^{2}}{2 \bullet 9,81} = 0,0195\ m$$
Wlot do zbiornika: ξ = 1
Wylot ze zbiornika: ξ = 0, 5
Nagłe zmniejszenie przekroju: $\xi_{9 - 10} = 0,5 \bullet \left( 1 - \left( \frac{d_{10}}{d_{9}} \right)^{2} \right) = 0,5 \bullet \left( 1 - \left( \frac{0,0083}{0,0123} \right)^{2} \right) = 0,272$
Nagłe zwiększenie przekroju: $\xi_{13 - 14} = \left( \left( \frac{d_{14}}{d_{13}} \right)^{2} - 1 \right)^{2} = \left( \left( \frac{0,0123}{0,00715} \right)^{2} - 1 \right)^{2} = 3,839$
$${h}_{9 - 10}^{\text{sm}} = \xi_{9 - 10}\frac{v_{1}^{2}}{2g} = 0,00273\ m$$
Straty na kolanku: hksm = 3(h2−h5) − 2(h2−h6) = 3 • (1,005−0,958) − 2 • (1,005−0,939) = 0, 009 = 0, 09 dm
Linie energii:
$$H_{1} = h_{c1} + \frac{p_{b}}{\text{ρg}} + \frac{v^{2}}{2g} = 1,030 + \frac{100000}{1000 \bullet 10} + 0 = 11,03\ m = 110,30\ dm$$
$$H_{2} = H_{1} - \xi_{\text{wylot}}\frac{v_{1}^{2}}{2g} = 11,03 - 0,5 \bullet \frac{{0,444}^{2}}{2 \bullet 10} = 11,025\ m = 110,25\ dm$$
H3 = H2 − h2 − 3sl = 11, 025 − 0, 0195 = 11, 006 m = 110, 06 dm
Linia ciśnień absolutnych:
$$H_{abs2} = H_{2} - \frac{v^{2}}{2g} = 11,025 - \frac{{0,444}^{2}}{2 \bullet 10} = 11,015\ m = 110,15\ dm$$
Linia ciśnień piezometrycznych:
$$H_{piez2} = H_{2} - \frac{p_{b}}{\text{ρg}} = 11,015 - \frac{100000}{1000 \bullet 10} = 1,015\ m = 10,15\ dm$$
Tablica wyników
|
|
|
|||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Lp | h | h+160mm | hc |
---|---|---|---|
mm | mm | dm | |
1 | 870 | 1030 | 110,30 |
2 | 845 | 1005 | 110,05 |
3 | 828 | 988 | 109,88 |
4 | 816 | 976 | 109,76 |
5 | 798 | 958 | 109,58 |
6 | 779 | 939 | 109,39 |
7 | 769 | 929 | 109,29 |
8 | 765 | 925 | 109,25 |
9 | 747 | 907 | 109,07 |
10 | 731 | 891 | 108,91 |
11 | 630 | 790 | 107,90 |
12 | 554 | 714 | 107,14 |
13 | 514 | 674 | 106,74 |
14 | 497 | 657 | 106,57 |
qv | v1 | Re1 | λ1 | v2 | Re2 | λ2 | v3 | Re3 | λ3 | ξwylot | ξwlot | ξ9-10 | ξ11-12 | ξ13-14 | hksm |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
dm3/h | m/s | m/s | m/s | dm | |||||||||||
190 | 0,444 | 4425 | 0,0388 | 0,975 | 6558 | 0,0352 | 1,314 | 7612 | 0,0339 | 0,5 | 1 | 0,272 | 0,129 | 3,839 | 0,09 |
Lp. | Nazwa | d | l/d | ζ | Δhs | ∑Δhs |
---|---|---|---|---|---|---|
- | - | mm | - | - | cm | cm |
1 | Wl | 12,3 | - | 0,50 | 0,5 | 0,5 |
2 | Wl_Ko | 12,3 | 50 | - | 1,9 | 2,4 |
3 | Ko | 12,3 | - | 0,24 | 0,9 | 3,3 |
4 | Ko_Ko | 12,3 | 100 | - | 5,5 | 8,8 |
5 | Ko | 12,3 | - | 0,24 | 0,9 | 9,7 |
6 | Ko_wy | 12,3 | 15 | - | 0,6 | 10,3 |
7 | Wy | 12,3 | - | 1,24 | 1,0 | 11,3 |
8 | Wl | 12,3 | - | 0,50 | 0,5 | 11,8 |
9 | Wl_Zw | 12,3 | 50 | - | 1,9 | 13,7 |
10 | Zw | 8,30 | - | 0,272 | 1,3 | 15,0 |
11 | Zw_Zw | 8,30 | 30 | - | 5,0 | 20,0 |
12 | Zw | 7,15 | - | 0,129 | 1,1 | 21,1 |
13 | Zw_Ro | 7,15 | 30 | - | 8,8 | 29,9 |
14 | Ro | 12,3 | - | 3,839 | 3,8 | 33,7 |
15 | Ro_Wy | 12,3 | 48,5 | - | 2,8 | 36,5 |
16 | Wy | 12,3 | - | 1,24 | 1,0 | 37,5 |
- | Suma | - | - | - | 37,5 |
Wnioski