On Monday 23rd June 2000 (MNM Week 26) we reported the Annual Seminar and Summer Management Meeting of the EuroFlam consortium at Florence Italy on Wednesday 21st and Thursday 22nd June. Twelve Graduates/Visiting Investigators who presented their completed reports or progress reports attended the meeting. In this and the following editions of EuroFlam News,  we are publishing abstracts of the presentations made.

Simulation of Combustion with Hydrogen-Gas Mixtures in the Combustor of an Industrial Gas Turbine
by Heinz-Jörg Tomczak - ENEL

Best Presentation Award (Certificate plus a cheque for €150), was given by the Italian Committee for Flame Research - CI.

Abstract

The utilisation of hydrogen as a possible fuel for aircraft and missiles has been considered for several years, but nowadays its role become an essential one in the world's energy economy. The most important advantages for the use of hydrogen as a fuel are:

• Its high burning velocity;
• Wide flammability range;
• High heating value per unit weight;
• Great flame stability and;
• The availability of hydrogen in a fairly pure state.

In order to use a mixture of natural gas and hydrogen as a fuel in a combustor of an industrial gas turbine, the combustion parameters like temperature T, velocity or the distribution of species have to be investigated in this project.

Due to analyse the combustion of various mixtures, the CFD code FLUENT is to be used in this project. Two different grids for the simulation, generated with GAMBIT, used models, boundary conditions and the first results are presented.

NOx Prediction in Fluent With IFRF Subroutines
by Luigi Tecce - IFRF

Abstract

The work deals with NOx prediction as a post computation in a Pulverized Coal Combustion case. The simulation concerns the MMF5-2 (2,165 MW) experiments with Gottelborn HvbB (coal) and is made in two dimensional model on a structural grid of 20000 cells.

After the conversion of the Coal Combustion case in FLUENT 4.5 with IFRF Subroutines starts the evaluation of the NOx with the NOx-IFRFs Subroutines. The first stage determines the field of velocity, temperature and compositions of the mixture on the whole domain, as some average values of the fluctuating values, as we are deal with a turbulent flow.

The fluctuations of temperature are of utmost importance for the NOx prediction. This work, basing on models used in the IFRF subroutines for estimates of the influence of the parameters, that the program allows to select, on the predictions of the NOx both as individual components (Thermal, Prompt and Fuel NO) and Total NOx.

Physical scaling and Modelling of a Free Jet Burner
by Caroline Syred - UWCC

Abstract

Manufactures of burners, gas turbines and boilers run very expensive tests on large scale systems at their works. Experience has shown that scaling from small laboratory systems to larger units is unreliable. Therefore more reliable methods are needed such that results obtained on small scale units can be used to predict the performance of large scale units.

Using velocity scaling techniques, where velocities in the laboratory models match those of full size systems, scaling criteria will be investigated.

A prototype burner was built with changeable nozzles of different sizes. Velocity measurements are made using LDA techniques, for isothermal and combustion conditions using Methane and Acetylene, keeping a constant velocity for all the nozzles. Initial investigation has shown expected velocity profiles and turbulent intensity. The basic characteristics of a free jet have been identified. Small scale turbulence and stresses are now to be studied for each nozzle size and scaling parameters investigated.