This visual basic program will calculate the variuos blimp and envelope
data required to build a model blimp.
A photo of a blimp outline is used to get the basic blimp profile.
Using the photo in Microsoft Paint the outline in pixels can be obtained.
Start on the center line at the far left and continue over the upper
envelope to the far end at the center line. The raw pixel data are entered into a
notepad application with the x axis first then the y half radius values.
No labels or other data should be entered.
These pixels are converted into inches based on the given length of the envelope.
On running the program this file can be selected. The output file name can entered or use
the default name. Select the output data as in English or Metric.
The offsets will be displayed on running the program. These values are the x and y values
from the upper left top of the window (0,0) to the left most end point of the blimp image.
They should be the first values you have entered into the data file.
The number of pixel pairs will be displayed also.
The length can be entered in inches or cms.
The required number of gores can be entered as well.
A raw blimp outline can be displayed after running the program.
The useful data will be found in the output file.
The Blimp Is Back!
The gore outline is obtained by plotting the gore data from the file.
The blimp outline is obtained by plotting the blimp data from the file.
I ran three tests on the software; one was using the real length of a Goodyear blimp
(192 * 12 inches), one using a round "balloon", and an ellipsoid.
Comparing the real blimp data with the programs one gets reasonably good results.
| Program Calculated | Published Data | Comments |
| 2304 inches-given | 192 feet | Goodyear Columbia IV - length |
| 46.67 feet | 45.92 feet | diameter |
| 210728.6 ft^3 | 202700 ft^3 | volume |
| 13870.16 lbs | 12840 lbs | Spirit Of America - lift He |
| 22094.34 ft^2 | 21600 ft^2 | Europa - surface |
Comparing the a 36 inch round balloon (sphere) data with the programs calculations one also gets
reasonably good results.
| Program Calculated | Calculated by Hand | Comments |
| 36 inches-given | 36 inches | "length" |
| 36 inches | 36 inches | diameter |
| 14.13 ft^3 | 14.3 ft^3 | volume - 4/3*pi*r^3 |
| 0.93 lbs | 0.941 lbs | lift He - 65.82lbs/1000 |
| 28.35 ft^2 | 28.27 ft^2 | surface - 4*pi*r^2 |
| 56.66 inches | 56.55 inches | gore length - pi*d/2 |
Comparing the an ellipsoid of 584 by 151.56 inches data with the programs calculations
one also gets reasonably good results.
| Program Calculated | Calculated by Hand | Comments |
| 584 inches-given | 584 inches | length |
| 151.56 inches | 151.56 inches | diameters |
| 4010.15 ft^3 | 4034.8 ft^3 | volume |
| 263.95 lbs | 265.5 lbs | lift He - 65.82lbs/1000 |
| 1546.07 ft^2 | 1547.28 ft^2 | surface |
| 627.47 inches | .... inches | gore length |
You may download the software as:
BlimpSoftware.bin
Rename the file to BlimpSoftware.exe on your computer (This is so the Avast, etc.
will not get upset on it),
The default pixel data is included in the .exe file.
You may display the pixel data then copy and paste it into notepad if you wish.
The pixel data file BlimpPixels.txt
is here.
Be sure to check the calculated values against your expected values; no guaranties
on the results!
