CFD approach to predict the significance of the shape bluff body on flame stabilisation in lean premixed combustion of hydrogen-air mixtures

Abstract

Over the past two decades, Europe, particularly France, has put a lot of effort into further developing information on supersonic air-breathing including Ramjet and Scramjets, providing first-part design techniques, and facilitating the necessary innovations. In actual ramjet-powered missiles, free stream air enters the inlet of a ramjet which goes through the aerodynamic compression process called “Ram Compression”. This process increases the static temperature of the air. To get the higher temperatures caused by streamlined compression for realistic simulations on the ground, an air warming framework must be organised at the test site. Using an Air vitiator or a mix of vitiator and electric heaters is the best approach to generate temperature change that resembles flying conditions on the ground. The fuel selected is Hydrogen, which is further supplied with makeup oxygen to maintain the molecular percentage of oxygen. A variety of air heater chamber configurations with various flame stabilisation methods are evaluated. A validated FLUENT CFD Code using species transportation is used to investigate to model the burning of the air heater. The ignition characteristics and fire consistency of a lean premixed hydrogen-air combination in a combustor with diverse mathematical designs of the bluff body under unique physical and chemical constraints have been examined by settling a two-dimensional mathematical plan. The air vitiator structure is good for giving air at temperature scope of 400–1000 K, the strain between 20 and 35 bar at Mach numbers between 0.1 and 0.5, and an air mass stream pace of a reasonable amount. Sample air vitiator's performance parameters and design calculations for connect mode ramjet test facility are formulated in the paper.