Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Study of the catalyst on the regression rate of HTPB-based fuel grain for hybrid rocket propulsion using a 2D slab burner
Submission Author:
Lia Pimont , SP
Co-Authors:
Lia Pimont, Mariana Tarifa, KAMILA CARDOSO, Luiz Ferrão, Leonardo Henrique Gouvêa, Pedro Lacava
Presenter: Lia Pimont
doi://10.26678/ABCM.ENCIT2022.CIT22-0338
Abstract
After some catastrophic failure events on solid rocket motors in the American Space Program, being one of them the Space Shuttle Challenger accident in 1986, the National Aeronautics and Space Administration (NASA) began a search for alternatives to the solid boosters of Space-Shuttle, thus rescuing the study of the hybrid rocket motors. Hybrid rocket system have the potential to become of strategic interest in the aerospace industry due to its low cost, safety, thrust controllability and throttling. However, in classical configurations, crosslinked polymeric fuel grains usually deliver a lower regression rate as it can be seen in hybrid rocket motor applications when hydroxyl-terminated polybutadiene (HTPB) is used as pre-polymer and isophorone diisocyanate (IPDI) as cross-linker for instance. The regression rate is associated with the resistance to degradation and vaporization from the HTPB-based polymer matrix and, it presents lower results when compared to the liquefying fuel grains. In this context, the copper acetylacetonate (CuAA) catalyst was tested in order to verify its effectiveness in the degradation and burning of the grain, making it even more sensitive to the variation of the oxidant mass flux (GOX). For that, a 2D slab burner with a quartz window was used aiming at the visualization of the combustion process on the fuel surface as well as the analysis of temporal and spatial behavior of the regression rate so as to observe how the addition of CuAA to the HTPB grain influence the rate of regression during the burn. This approach, as opposed to the widely used end-point method, can identify transient phenomena, anomalies as well as temporal and spatial behavior. In addition, it is reliable considering preliminary studies. For the visualization methodology adopted in this work, the combustion port mean length over the burn time. Improvements were observed in the ease of ignition and burning rate.
Keywords
chemical propulsion, hybrid rocket motor, Regression Rate, HTPB
