le

PARACHUTE CALCULATIONS

1. Free-fall vertical velocity without air friction
2. Parachute vertical velocity with air friction
3. Dynamic wind pressure
4. Temperature lapse rate
5. Pressure at altitude h above sea level
6. Density of air
7. Real and projected parachute surface. Influence in vertical velocity calculations.
Parachute drag coefficent.

8. Spreadsheet including the above formulation


1. Free-fall vertical velocity without air friction
Free-fall vertical velocity

Free-fall vertical velocity
without air friction




h (m) v (m/s) v (km/h)



0,5 3,13 11,28
1 4,43 15,95
1,5 5,42 19,53
2 6,26 22,55
2,5 7,00 25,21
3 7,67 27,62
3,5 8,29 29,83
4 8,86 31,89
4,5 9,40 33,83
5 9,90 35,66
10 14,01 50,43
25 22,15 79,73
50 31,32 112,76
100 44,29 159,46
150 54,25 195,3
200 62,64 225,51


2. Parachute vertical velocity with air friction
Parachute vertical velocity

3. Dynamic wind pressure
Dynamic wind pressure

4. Temperature lapse rate
Temperature lapse rate

h (m) T (ºC)


0 15,0
50 14,7
100 14,4
150 14,0
200 13,7
250 13,4
300 13,1
500 11,8
1000 8,5
1500 5,3
2000 2,0
2500 -1,3
3000 -4,5
3500 -7,8
4000 -11,0
4500 -14,3
5000 -17,5
Temperature variation al altitude h above sea level. Example with 15ºC at 0 m.


5. Pressure at altitude h above sea level

5.1  Pressure at altitude h above sea level
Pressure at altitude h

5.2 Pressure at altitude h in isothermic atmosphere (Laplace law)
Pressure at altitude h Laplace


6. Density of air
Density of air
Density of air is 1,225 kg/m3 at ISA atmosphere 15ºC (=288,15ºK) and 1013,25 hPa.


7. Real and projected parachute surface. Influence in vertical velocity calculations.
Parachute drag coefficent.
Real and projected parachute surface calculus


8. Spreadsheet including the above formulation

Parachute calculations.xls  (MS Excell .xls format)

Parachute calculations.odf (Open Office spreadsheet .odf format)


Please send comments to pere AT laboratoridenvol DOT com

  Return to Laboratori d'envol