Combustion characteristics of a liquid hydrocarbon fueled scramjet
Work towards MSc degree under the supervision of Assis. Prof. Dan Michaels & Assis. Prof. Joe Lefkowitz (Technion)
Department of Aerospace Engineering
Technion – Israel Institute of Technology
This seminar presents the results of an experimental study on combustion characteristics of a liquid hydrocarbon-fueled scramjet. Liquid hydrocarbons are the preferred fuel choice for Mach 5-8 cruise flight due to higher energy density as compared to H2 or lighter hydrocarbons, as well as their endothermic properties when used as a heat sink. There are however major challenges associated with liquid supersonic combustion; the fuel must atomize, vaporize and adequately mix within a limited residence time, making it far from a rudimentary effort. In this study, ignition and stabilization are assisted by a spark plug, a hydrogen pilot flame and fuel preheating as would happen in cooling channels. Especially the last mentioned is not fully understood; the mixing behavior and fuel entrainment rate into the cavity fundamentally changes when the fuel flash-boils upon injection after being superheated. Therefore, this research investigates the effect of superheating a liquid hydrocarbon (n-dodecane, C12H26) on the mixing behavior and consequently on the flame-stability and combustion efficiency in a cavity-stabilized scramjet combustion model. The Mach 2.2 airflow has stagnation conditions of 12atm and 1275K. Liquid fuel is injected upstream of the cavity at room temperature and in a superheated state, which is delivered by a fuel heating system that is able to preheat the fuel under pressurized conditions to 300°C. The spark plug and hydrogen injection port are located in the cavity. Information on flame development is obtained using pressure measurements along the combustion length and CH* luminosity captured by high-speed imaging.
The talk will be given in English
Wed, 16-06-2021, 16:30 (Zoom Meeting)https://technion.zoom.us/j/95796782831