Simulation of the Influence of Air Preheat Combustion on the Temperature of Propane Turbulent Flame Using Probability Density Function Approach and Eddy Dissipation Model

Abstract

This paper presents results obtained from the application of a computational fluid dynamics (CFD) code Fluent 6.3 to modelling of temperature in propane flames with air preheat. The study focuses on investigating the effect of air preheat temperature on the temperature of the flame. A standard k-ε turbulence model in combination with the Probability Density Function (PDF) model for Non Premix Combustion model and Eddy Dissipation Model (EDM) are utilized to represent the flow and temperature fields of the flame being investigated, respectively. The results of calculations are compared with experimental data of propane flame taken from literature. The results of the study showed that the combination of the standard k-ε turbulence model and PDF model is more capable of producing reasonable predictions of temperature, particularly in axial profile and rich fuel area of all two flames compared with those of EDM model. Both experimental works and numerical simulation showed that increasing the temperature of the combustion air significantly increases the flame temperature.

On the Importance of Model Selection for CFD Analysis of High Temperature Gas-Solid Reactive Flow; Case Study: Post Combustion Chamber of HIsarna Off-Gas System

“…A more pronounced discrepancy can be seen for CO profile in the same region where FR-EDM-rex predict lower CO mole fraction (higher CO conversion). This means that higher reaction rate is predicted by FR-EDM-rex which has been reported by other reviewed studies [53][54][55][56][57][58].…”

“…Using EDM, they have reported an over heat of the flow and extra release of heat near the fuel rich region (equivalence ration = 1.4); however, this over prediction is reported to be minor for leaner mixture (equivalence ration = 1). The same temperature overestimation by EDM is reported by other researchers [54][55][56][57]. In another interesting research, Parente et al [58] have studied the application of FR-EDM and EDC using experimental and numerical analysis for an industrial burner.…”

“…The products are instantaneously formed once the reactants are mixed and the overall rate of reaction is controlled by turbulent mixing. This way, calculation of R i is mixing limited meaning that it is purely calculated based on the local mixing properties of the flow (turbulent kinetic energy k and its dissipation rate ε)without considering finite rate constants and kinetic data [53,55,57]. In applications where ignition is important or when chemical kinetics control the reaction rate, using EDM will lead to a poorly predicted properties.…”