Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Characteristic Lengths of Liquid Propellant Rocket Engines and the Influence of Chemical Reactions
Submission Author:
Maurício Sá Gontijo , DF
Co-Authors:
Maurício Sá Gontijo, Gustavo Alexandre Achilles Fischer, FERNANDO DE SOUZA COSTA
Presenter: Maurício Sá Gontijo
doi://10.26678/ABCM.COBEM2021.COB2021-2105
Abstract
The characteristic length (L*) is an extremely important parameter on the design of liquid propellant rocket engines (LPREs) and it is being studied in several works through many years. In addition, the atomization plays a fundamental role on the prediction of the L* and it can be measured by the Sauter Mean Diameter (SMD). Also, chemical reactions may have a considerable influence on the results of these predictions. It is proposed in this work an algorithm that evaluates the SMD effects and the influence of chemical reactions on the characteristic length with a low computational cost, providing a powerful tool for propulsion engineers. Additionally, the algorithm was validated with real consecrated engines using three propellant mixtures, the ethanol/liquid oxygen, RP-1/liquid oxygen and liquid hydrogen/liquid oxygen, on a range of 20 to 260 bar of chamber pressure. In addition, a comparison of L* for these propellant mixtures was conducted simulating the L75 rocket engine. The results showed that the increase of the L*, when it is not considered that chemical reactions occurs in a infinitesimal length, varies from approximately 1.5% to 20.3%, with an average of 8.42% and that there is an average value of equivalence ratio required to reach the minimum L* in function of the propellant mixture.
Keywords
Characteristic Lengths, Sauter Mean Diameters, Chemical reactions, Liquid Propellant Rocket Engines
