Fluid Flow mode results for the RR1 example simulation
- Last UpdatedOct 04, 2024
- 3 minute read
The following table shows the final design of the vacuum transfer line.
|
Pipe |
Number of Segments |
Inside Diameter |
Length |
Elevation Change |
|||
|---|---|---|---|---|---|---|---|
|
mm |
in |
m |
ft |
m |
ft |
||
|
HP1 |
5 |
428.65 |
16.876 |
3.048 |
10 |
0 |
0 |
|
HP2 |
5 |
381.00 |
15.000 |
3.048 |
10 |
0 |
0 |
|
VP1 |
5 |
428.65 |
16.876 |
9.144 |
30 |
9.144 |
30 |
|
VTL1 |
10 |
742.95 |
29.250 |
30.48 |
100 |
0 |
0 |
|
VTL2 |
10 |
844.55 |
33.250 |
53.34 |
175 |
0 |
0 |
|
VTL3 |
10 |
996.95 |
39.250 |
54.86 |
180 |
0 |
0 |
The following table displays the pressure and velocity profile from FF 1 snapshot when you set the column pressure to 35 mmHg. Observe that because all three pipes are incrementally getting larger, we do not achieve critical velocity in any section of pipe.
|
Pipe |
Segment |
Segment Length (m) |
Cumulative Length (m) |
Inlet Pressure (mmHg) |
Outlet Pressure (mmHg) |
DP (mmHg) |
Fluid Velocity (m/s) |
Critical Flow Approach (faction) |
|---|---|---|---|---|---|---|---|---|
|
VTL1 |
1 |
3.98 |
3.98 |
94.61 |
92.36 |
2.26 |
59.28 |
0.55 |
|
2 |
3.78 |
7.75 |
92.36 |
90.10 |
2.26 |
60.90 |
0.56 |
|
|
3 |
3.57 |
11.32 |
90.10 |
87.85 |
2.26 |
62.60 |
0.58 |
|
|
4 |
3.36 |
14.69 |
87.85 |
85.59 |
2.26 |
64.40 |
0.59 |
|
|
5 |
3.16 |
17.85 |
85.59 |
83.33 |
2.26 |
66.29 |
0.61 |
|
|
6 |
2.95 |
20.80 |
83.33 |
81.08 |
2.26 |
68.30 |
0.63 |
|
|
7 |
2.74 |
23.54 |
81.08 |
78.82 |
2.26 |
70.42 |
0.64 |
|
|
8 |
2.53 |
26.06 |
78.82 |
76.57 |
2.26 |
72.66 |
0.66 |
|
|
9 |
2.32 |
28.38 |
76.57 |
74.31 |
2.26 |
75.05 |
0.69 |
|
|
10 |
2.10 |
30.48 |
74.31 |
72.06 |
2.26 |
77.59 |
0.71 |
|
|
VTL2 |
1 |
8.41 |
38.89 |
54.13 |
78.42 |
75.41 |
3.01 |
57.26 |
|
2 |
7.75 |
46.64 |
61.88 |
75.41 |
72.40 |
3.01 |
59.83 |
|
|
3 |
7.08 |
53.72 |
68.96 |
72.40 |
69.39 |
3.01 |
62.63 |
|
|
4 |
6.40 |
60.12 |
75.36 |
69.39 |
66.39 |
3.01 |
65.68 |
|
|
5 |
5.72 |
65.84 |
81.08 |
66.39 |
63.38 |
3.01 |
69.04 |
|
|
6 |
5.03 |
70.86 |
86.10 |
63.38 |
60.37 |
3.01 |
72.73 |
|
|
7 |
4.33 |
75.19 |
90.43 |
60.37 |
57.36 |
3.01 |
76.82 |
|
|
8 |
3.61 |
78.80 |
94.04 |
57.36 |
54.35 |
3.01 |
81.37 |
|
|
9 |
2.88 |
81.68 |
96.92 |
54.35 |
51.34 |
3.01 |
86.46 |
|
|
10 |
2.14 |
83.82 |
99.06 |
51.34 |
48.34 |
3.01 |
92.20 |
|
|
VTL3 |
1 |
8.55 |
92.37 |
107.61 |
55.11 |
53.10 |
2.01 |
60.01 |
|
2 |
7.89 |
100.26 |
115.50 |
53.10 |
51.09 |
2.01 |
62.53 |
|
|
3 |
7.22 |
107.48 |
122.72 |
51.09 |
49.08 |
2.01 |
65.26 |
|
|
4 |
6.55 |
114.03 |
129.27 |
49.08 |
47.07 |
2.01 |
68.23 |
|
|
5 |
5.87 |
119.90 |
135.14 |
47.07 |
45.06 |
2.01 |
71.46 |
|
|
6 |
5.18 |
125.08 |
140.32 |
45.06 |
43.04 |
2.01 |
75.00 |
|
|
7 |
4.48 |
129.57 |
144.81 |
43.04 |
41.03 |
2.01 |
78.90 |
|
|
8 |
3.77 |
133.34 |
148.58 |
41.03 |
39.02 |
2.01 |
83.20 |
|
|
9 |
3.04 |
136.38 |
151.62 |
39.02 |
37.01 |
2.01 |
87.97 |
|
|
10 |
2.30 |
138.68 |
153.92 |
37.01 |
35.00 |
2.01 |
93.31 |
The following figure displays the pressure profile through the VTL pipe to the vacuum column. Since there are enlargers between the three VTL pipes, you can see pressure recovery between each pipe.
The following figure displays the fluid velocity as a function of approach to critical flow (Mach number) through the VTL pipes.
To demonstrate the impact of proper pipe sizing, the following table displays the pressure profile when VTL3 is undersized from 40 in to 36 in. Observe that we achieve critical velocity at the end of VTL3 and you can observer a pressure discontinuity at the entrance to the vacuum column flash zone.
|
Pipe |
Segment |
Segment Length (m) |
Cumulative Length (m) |
Inlet Pressure (mmHg) |
Outlet Pressure (mmHg) |
DP (mmHg) |
Fluid Velocity (m/s) |
Critical Flow Approach (faction) |
|---|---|---|---|---|---|---|---|---|
|
VTL3 |
1 |
10.62 |
94.44 |
78.71 |
74.87 |
3.85 |
57.65 |
0.53 |
|
2 |
9.53 |
103.96 |
74.87 |
71.02 |
3.85 |
61.02 |
0.56 |
|
|
3 |
8.42 |
112.38 |
71.02 |
67.17 |
3.85 |
64.79 |
0.59 |
|
|
4 |
7.31 |
119.69 |
67.17 |
63.33 |
3.85 |
69.03 |
0.63 |
|
|
5 |
6.18 |
125.87 |
63.33 |
59.48 |
3.85 |
73.82 |
0.67 |
|
|
6 |
5.02 |
130.89 |
59.48 |
55.64 |
3.85 |
79.29 |
0.72 |
|
|
7 |
3.84 |
134.73 |
55.64 |
51.79 |
3.85 |
85.59 |
0.77 |
|
|
8 |
2.61 |
137.34 |
51.79 |
47.95 |
3.85 |
92.91 |
0.84 |
|
|
9 |
1.34 |
138.68 |
47.95 |
44.10 |
3.85 |
101.53 |
0.91 |
|
|
10 |
0.01 |
138.68 |
44.10 |
40.26 |
3.85 |
111.82 |
1.00 |
The Pressure and Velocity Profile plot shows the outlet pressure and velocity by segment for all three pipes. Because we define different lengths and equal pressure drops for the pipe segments, the segment-wise plot is different than the length-wise plots presented in the preceding figures.
