A python program to calculate the scientific parameters of launching of a totally-not-for-spying weather balloon.
I decided to write a function to calculate a second by second launch of a weather balloon to a given altitude, and to produce a graphical output of it's journey.
The purpose was to explore what differences different parameters can make, and to understand the regimes of the atmosphere in which these balloons operate. Neat.
Download the source code and run manually from the command line, any OS:
python3 ./balloonwars.py --help
Edit parameters inside the script.
Lots.
- Pressure of balloon compression
- Effects of temperature absorbtion
- Burst heigh calculations (material science i guess)
- Any kind of lat/long prediction or descent profile (post-burst)
- Reasonable documentation
Also Lots.
- cli output
- graph output (multiple windows)
- cross-calculated data at every interval (1 second)
- tabulated textual output (recommended screen wide with small font)
matplotlib.pyplot for graphs pandas for tabulated data, feeds into matplotlib ambiance for standard altitude readings
Most published results show the coefficient of drag for a sphere at Re=10,000 to be at or near 0.4. From there Cd increases to a broad maximum between 0.45 and 0.50 around Re=100,000 (Figure 2). As the curve continues, it drops off again as critical turbulence is reached at Re ~ 200,000. The simulation results in this study show Cd decreasing slightly between Re=10,000 and Re=100,000
The C_{dr} CoD should be considered a function of Re and practically of altitude. In our model we will set the drag coefficient at 0.47; that will be a value too high for ground conditions and far more appropriate for low Re high altitude conditions https://www.basicairdata.eu/knowledge-center/design/introduction-to-weather-balloons/
REASONABLE SANITY NUMBERS
- pressure_sealevel_kp = 1013.25
- pressure_ceiling_kp = 10
- sound_m_s_high = 340
- sound_m_s_low = 200
