Aerody - Fundamentals

Zeroth Law of Thermodynamics

If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other.

First Law of Thermodynamics

Energy cannot be created or destroyed; it can only be transformed from one form to another. This law is often expressed as the principle of conservation of energy.

Second Law of Thermodynamics

In any energy transfer, the total entropy of a closed system can never decrease over time. This means that energy systems tend to move towards a state of disorder or randomness.

Third Law of Thermodynamics

As the temperature of a system approaches absolute zero, the entropy of a perfect crystal approaches zero.

1.01325 Bar

Atmospheric Constant (Bar)

33.9 ft H₂O

Atmospheric Constant (ft H₂O)

760 mmHg/ Torr

Atmospheric Constant (mm Hg/ Torr)

101325 Pa

Atmospheric Constant (Pa)

29.92 in Hg

Atmospheric Constant (in Hg)

14.7 psi

Atmospheric Constant (psi)

2116.8 psf

Atmospheric Constant (psf)

3.28 ft

1m = _ft

0.621 mi

1km = _mi

5280ft

1mi = _ft

2.205 lb_m

1kg = _lb_m

32.174 lb_m

1slug = _ lb_m

9.8066 N

1kg_f =_N

0.225 lb_f

1N = _ lb_f

47.88 Pa

1 psf = _ Pa

273

Celsius to Kelvin add _

460

Fahrenheit to Rankine add_

519 ^oR
288 K

Tropo Temp constant

-0.003566 ^oR/ft
-0.00651 K/m

Tropo Lapse Rate

0.002377 slug/ft³

1.225 kg/m³

Tropo Density

1.940 slug/ft³

1000 kg/m³

Water Density

53.342 ft lb/ lb ^oR
287.08 J / kg K

Universal Gas Constant

20.05 √T ;
49.02 √T ;

Speed of Sound Formula

36 080 ft - 104 960 ft
11 km - 32 km

Strato Altitude

390.44 ^oR
216.6 K

Strato Temp

0.223P_o

Strato P_ref

0.297ρ_o , english

0.296ρ_o ,metric

Strato ρ_ref

1.852 km/hr
0.514 m/s

1 knot = _ km/hr
= m/s

1.1508 mi/hr
1.689 ft/s

1 knot = _ mi/hr
= ft/s

3.7374 × 10^-7 slug/ ft sec

1.7894 × 10^-5 kg/ m sec

μ_o