Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Development of the 3D printed fuel grain for a solid-fuel ramjet engine
Submission Author:
Danielle Lima Bezerra , DF
Co-Authors:
Danielle Lima Bezerra, Olexiy Shynkarenko
Presenter: Danielle Lima Bezerra
doi://10.26678/ABCM.COBEM2021.COB2021-0074
Abstract
Solid-fuel ramjet (SFRJ) is a perspective propulsion system invented for tactile missiles, currently under investigation by many research groups. This motor has a simple structure and provides reliable propulsion characteristics. The Chemical Propulsion Laboratory of the University of Brasilia has built the test SFRJ working on paraffin and polyethylene fuels. A solid-fuel ramjet's primary design challenge is to organize optimal combustion of the solid fuel in incoming high-velocity airflow. High-regression rate fuels like paraffin allow creating a compact combustion chamber and optimize the motor's size. However, such a solution requires an additional investigation on the motor performance, addressed to control the oxidizer-to-fuel ratio. 3D printing of the fuel charge is one of the methods currently used to overcome the disadvantages of simple one-port cylindrical grains in the hybrid of air-breathing propulsion: non-uniformity of the regression rate and variation of SFRJ performance in time. The research aims to create a composite paraffin-ABS fuel grain to ensure a constant fuel mass flow rate during the motor operation. The other current work goals are analyzing the motor operating conditions, reviewing the 3D-printed grain geometries, their advantages, and disadvantages, and building a composite grain design methodology. The object of study is widely presented in the literature. The reference publications provide analytical and empirical models about the fuel grain design. Current development is based on the Laboratory's previous experimental work, allowing a more accurate fuel regression calculation. The compressible flow model with chemical reactions allowed obtaining the motor's flow properties in the combustion chamber. The fuel regression in time was calculated numerically, integrating the regression law with the flow equations. The 3-D printed fuel grain casing is ready to be tested on the test bench at the Laboratory. Due to the quarantine restrictions in 2020 - 2021, an extensive study on motor performance was provided using analytical calculation and numerical simulation, including the protection layer regression rate, paraffin regression rate, and grain degradation. The theoretical analysis results correspond with other research groups' studies and complement solid-fuel ramjet knowledge with new data.
Keywords
solid-fuel ramjet, Additive manufacturing, composite fuel grain, Regression Rate, air-breathing propulsion, Numerical Methods
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