Experimental Testing of Spray Characteristics of Swirler Injector without Guide Vanes in Liquid Propellant Rocket Engines

This paper studies the “Experimental testing of spray characteristics of swirler injector without guide vanes in Liquid Propellant Rocket Engines”. The purpose of a fuel injector is to inject and control the flow of the propellants into the combustion chamber. It consists of Tangential ports, a swirls chamber, a converging spin chamber, and a discharge orifice. Kerosene as fuel and liquid oxygen as oxidizer were employed here. To pressurize the propellants, nitrogen gas is used and the pressurized pipeline is controlled with an open/close ball valve and measure the inlet pressure using a pressure gauge. When a propellant comes through the inlet has a tangential velocity and it causes the propellants to swirl inside the swirl chamber at the exit the propellant comes with rotational momentum and forms a liquid film and then the friction between the propellant and air accelerates and disrupts the liquid film and converts into very tiny droplets. The exit mass flow rate, spray cone angle, and spray cone length with different inlet pressures and inlet diameters are measured. A graph is plotted between inlet pressure, and spray cone angle, penetration length. The theoretical mass flow rate is calculated using Bernoulli’s equation, taking the coefficient of the discharge as one and plotted a graph with the given data and comparing it with the experimental data. The accurate atomization increases the combustion efficiency, burns the propellant completely without leaving any unburnt propellant in the combustion chamber, and minimizes combustion instability.