Introduction

Air Liquide uses a presumed PDF model for turbulent combustion simulations in industrial furnaces. This model requires a number of pre-computed, PDF-averaged equilibrium variables such as equilibrium species mole or mass fractions or enthalpy.

Such equilibrium variables are typically computed a priori and stored in a CFD look-up table or a database. Such a look-up table is then read at the start of a CFD simulation and the equilibrium variables are retrieved during the iterative solution process.

Objectives

Dacolt has developed a customised software package to create equilibrium CFD look-up tables for Air Liquide, called ePDF, based on the equilibrium solver of the open source package Cantera. ePDF has been created to meet specific requirements of Air Liquide.

ePDF features

A set of pre-defined complex fuels are availabe in ePDF, including:

• gaseous fuels like natural gas, cokes gas or blast furnace gas
• liquid (heavy hydrocarbon) fuels
• solid fuels like coal

ePDF also accounts for:

• multiple mixture fraction streams
• PDF integration
• enthalpy variations

The look-up tables generated by ePDF can be exploited within CFD simulations using multi-dimensional interpolation routines, also provided by Dacolt.

Results

The image illustrates typical output of ePDF, with normalised mole fractions of methane, oxygen and carbon monoxide as a function of mixture fraction.