Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
PROPULSION PARAMETERS OF THERMALLY PERFECT GASES
Submission Author:
FERNANDO DE SOUZA COSTA , SP
Co-Authors:
Maycol M. Vargas
Presenter: FERNANDO DE SOUZA COSTA
doi://10.26678/ABCM.ENCIT2016.CIT2016-0089
Abstract
Propulsive parameters of rockets are usually defined for perfect gases with constant properties. However propellants can reach high temperatures in the chamber and the specific heats of the exhaustion gases can vary significantly throughout the nozzle, especially if they contain polyatomic molecules. This paper derives equations for propulsion parameters of rockets, including specific impulse, characteristic velocity, critical mass flow constant and thrust coefficient, assuming isentropic one-dimensional flow of thermally perfect gases. Theoretical results for CO2, H2O and N2 flows are obtained considering specific heats obeying NASA fourth order polynomials of temperature.
Keywords
Propulsion parameters, Thermally perfect gases, NASA polynomials, Critical mass flow constant
