Ratings and main standard values
Aerospace propulsion - An introduction

The units most commonly used in this article are those of the International System (SI). Speed is expressed in meters per second (m/s^-1), pressure in pascals (Pa), or even in bars (1 bar = 105 Pa) or MPa. The thermodynamic quantities of fluids involved in propulsion involving joules (J) or watts (W), for example specific heat capacities (c_p, c_V, and by extension r), are in J.kg^-1.K^-1. Temperatures are expressed in kelvins (K).

The main Anglo-Saxon units still used in articles and works on propulsion are listed below:

• For pressure, 1 psi (pound per square inch) corresponds to 6,897 Pa (which is why some reference pressures for propellants are given as 70 bar)....