1. Rocket Nomenclature EGR 4347 Analysis and Design of Propulsion Systems

2. Nomenclature P c = chamber pressure (initial total pressure of the nozzle system) T c = chamber temperature (initial total temperature of the nozzle system) P n = nozzle pressure ratio Pc/Pa P e = nozzle exit pressure Pressure ratio to which the nozzle is designed such that P e = P a

3. Ideal Rocket Thrust

4. Force required to hold a rocket at rest as the rocket ejects a propellant rearward under the following conditions: – P atm acts everywhere on the rocket’s external surface – Propellant flow rate is constant – The rate of change of momentum within the rocket is negligible – Isentropic flow through nozzle, total pressure and temperatures are constant

5. Specific Impulse I sp F i ~ mdot*V exit I sp ~ V exit I sp ~ 1/S units (s) Higher exit velocity – more thrust for a given amount of propellant

6. Characteristic Velocity C* “*” does not mean sonic conditions Characteristic of reaction process Units of velocity

7. Characteristic Velocity C* Theoretical Experimental R, T c, and  are thermochemical calculations P c, A t, and massflow are experimentally measured C* experimental should be more than 90% of C* theoretical

8. Thrust Coefficient C Fi Numerical values between 0.6 and 2.2 Figure of merit independent of rocket size