Ballistic Evaluation of Hybrid Ducted Rocket Engine Using Boron and Iron Based Solid Fuels

Abstract

The basic need for a lifting device is high energy and high-density fuel. Boron has the capacity to address these demands. As stated in the literature, boron always has boron oxide (B2O3) on its surface. Boron burns in two stages, the first of which is concerned with the elimination of boron oxide by the particle's local heat, and the second with the ignition of core boron. The B2O3 (protective layer) melts when the temperature surpasses the melting point of boron oxide and as a result, the boron particles are removed. The core boron then ignites and flames with a magnificent green blaze. The green color represents the emission of BO and BO2, which are intermediate species of boron combustion. A two-stage combustion chamber is always promoted by an effective boron combustion, which is connected to contemporary ramjet variations such as solid fuel ramjet and solid fuel ducted rocket engines. The current concept involves a hybrid engine based on ducted rocket principles. This engine features two combustion chambers, with the first, known as the primary combustor or gas generator, containing boron-wax-based solid fuel. Similarly, iron is added to the fuel, accounting for 10% to 20% of the total boron loading in the wax-boron combination. There are three fuel compositions being studied: pure wax, wax/boron, and wax/boron/Iron. When the rocket is started, the solid fuel in the main combustor burns with the help of controlled oxygen, and the combustible products comprising partially burnt boron particles combine with oxygen in the mixing zone, which is divided by primary and secondary combustion chambers. Boron particles are intended to completely burn in the secondary combustor before exiting the exhaust nozzle. Iron burns first in the main combustor, delivering energy to boron particles that melt the boron oxide layer before the core boron ignites. Therefore, the boron particles in the primary combustor burn effectively, while the partially burnt boron particles in the secondary combustor ignite. As a result, iron particles improve the combustion process of boron-based solid fuel. The emphasis here is on two significant studies: the solid fuel regression rate and the burning efficiency using pre-and-post combustion analysis. To estimate the percentage residual active boron content, the condensed combustion products (burned products) are collected and analyzed in a thermogravimetric (TG) device. As a result, the characterization investigation will offer a clear image of the residual boron contained in the burnt product. These tests give information on the overall performance of our new static hybrid fuel ducted rocket design and be used in missile applications.