Tank Estimator
 Share
The version of the browser you are using is no longer supported. Please upgrade to a supported browser.Dismiss

 
View only
 
 
Still loading...
ABCDEFGHIJKLMNOPQRSTUVWXYZ
1
This sheet estimates the mass and other characteristics of simple isogrid or 'balloon' tanks
2
Tanks are assumed to be spherical or cylinders with spherical endcaps.
3
Cylinders are assumed to have fuel and oxidizer separated by a bulkhead.
4
5
Use with caution; these are first-cut estimates and ignore many parts (like plumbing and impermeable liners).
6
7
Author:Chris Wolfe
8
9
Instructions:
10
This sheet is read-only. Make a copy into your own Google Docs account and you will have full control.
11
A variety of examples are already present. To run your own numbers, use the empty first column in either tab. Existing columns can be repurposed as well.
12
Most rows have a note describing what the value is or how the result is calculated. Hover over the cell on the far left to see these notes.
13
Enter values in the light-orange shaded cells. Results will be displayed below. Once the first 22 rows are filled in, suggested minimum thicknesses will appear.
14
You may manually enter the suggested values or round as desired.
15
For cargo tanks, enter the cargo fluid properties in both the fuel and the oxidizer sections, set the ratio to 1 and set the bulkhead thickness to 0.
16
Tank skin mass is a reliable number. Unburned fuel is a bit less solid. Ullage numbers have not been validated and could be wildly inaccurate.
17
Each tank will include an estimated mass of cryocooler and PV panels for active boiloff control near Earth; this ignores power conversion and storage mass.
18
Each tank will also include dimensions for various packing methods.
19
20
Changelist
21
8/13/2015
First public version
22
2/8/2016
Changed liquid hydrogen density from 67.8 to 70.8
23
8/29/2016
Improved annotation; corrected the 'vertex radius' formulae;
24
converted helium ullage tanks to fit around the endcaps of the main tanks
25
9/6/2016
Added fields for fill factor (percent of available volume filled) and structural factor (percent of base mass added for valves, lines, sensors, structural reinforcement, etc.)
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
Loading...
 
 
 
About
Balloon or Isogrid common bulkhead
Spherical