Session: 04-30 Emissions - hydrogen/ammonia III

Paper Number: 128988

128988 - Predicting NOx Emissions of a Lean Hydrogen Flame Using High and Low Order CFD Models 

The recent efforts in numerical methods to study hydrogen combustion have allowed the development of affordable and reliable strategies that can reproduce the main structure of the flame. Although this objective represents a vital goal of the design process of a new combustor, properly estimating the emission remains an aspect that must be further investigated. In fact, due to the lack of experimental data, few numerical works addressed the evaluation of NOx emissions in hydrogen-fuelled rigs. The present work aims to study turbulent combustion and NOx emission formation through different numerical approaches on a laboratory-scale atmospheric rig. The burner consists of a swirl-stabilized, technically premixed hydrogen-air flame, with detailed NOx emissions estimated via an experimental campaign at the University of Berlin (TUB). A first estimation is obtained through a high-fidelity simulation performed in order to assess the capability of a computationally expensive strategy to estimate NOx emissions. In particular, a species transport simulation adopting a Thickened Flame Model in which NOx chemistry is included is carried out. After that, two cost-efficient methods are explored, allowing a quick assessment of the NOx. In both cases, time average fields come from a preceding species transport calculation with simplified chemistry. In the first case, the NOx equations are performed on a frozen RANS framework as a post-processed stage, while in the second strategy, a chemical reactor network is constructed to obtain NOx emissions. The computational accuracy of each approach is compared and discussed, with emphasis on computational cost. 

Presenting Author: Matteo Amerighi University of Florence

Presenting Author Biography: Matteo Amerighi is a Ph.D. student at the Department of Industrial Engineering at the University of Florence. He graduated in 2020 in mechanical engineering and his background includes CFD modeling of reactive and multi-phase flow, mainly for gas turbine applications. Currently, his main research topic is the numerical modeling of hydrogen combustion focusing on the ignition phase within the European project HESTIA.

Authors:

Matteo Amerighi University of Florence
Antonio Andreini University of Florence
Stefano Orsino ANSYS
Ishan Verma ANSYS
Rakesh Yadav ANSYS
Thoralf Reichel Technische Universität Berlin
Tom Tanneberger Technische Universität Berlin
Oliver Paschereit Technische Universität Berlin