CFD Modeling of Kerosene Combustion with Various Initial Conditions and Fuel Droplet Diameters

Abstract

This paper presents the numerical models for the analysis of combustor fuel spray, characteristics, in various injection conditions in a can type of combustor with a double stage radial swirler. Spray consists of two fundamental and consecutive steps, means the primary breakup and the secondary breakup. The primary breakup is modeled by Linearized Instability Sheet Atomization (LISA) which are mostly used in a pressure swirl atomizers. Secondary breakup is modeled by Taylor analogy breakup model (TAB). The trajectory and velocity of generated fuel droplets is determined by Lagrangian Particle Tracking. Characteristics of jet breakup, depends on a variety of factors such as turbulence, injection pressure drop, velocity profiles, nozzle geometry, and the physical state of the liquid fuel. In this paper Jet-A aviation fuel (kerosene), modeled as a two-component surrogate fuel (by mass 60 % C10H22 and 40 % C9H12). The standard k–ε model with the enhanced wall treatment and the Euler-Lagrange method were employed for the simulation of the turbulence and spray. All results of the simulation in this paper are analyzing in 3 various injection conditions and one of these cases was chosen and implemented in a real annular combustion chamber of a gas turbine. A PDF Flamelet model was employed to simulate combustion process. Introduction The process of liquid atomization has applications in numerous industrial branches, for example, in chemical, mechanical, aerospace, and civil engineering as well as in material science and technology and metallurgy, food processing, pharmaceuticals, agriculture and forestry, environmental protection, medicine, and others [1] and is essentially one in which bulk fuel is converted into small drops. It represents a disruption of the consolidating influence of surface tension by the action of internal and external forces. In the absence of such disruptive forces, surface tension tends to pull the liquid into the form of a sphere, which has the minimum surface energy. Liquid viscosity has an adverse effect on atomization because it opposes any change in system geometry. On the other hand, aerodynamic forces acting on the liquid surface promote the disruption process by applying an external distorting force to the bulk liquid. Breakup occurs when the magnitude of the disruptive force just exceeds the consolidating surface tension force [2]. The atomization process is generally regarded as comprising two separate processes-primary atomiz…