The Importance of Detailed Chemical Mechanisms in Gas Turbine Combustion Simulations

Abstract

<p>This paper – in memory of Jürgen Warnatz – summarizes selected recent papers of the Chemical Kinetics Group at the German Aerospace Center in Stuttgart. It shows the need for detailed chemical reaction mechanisms to understand practical combustion systems. A comprehensive description of combustion processes based on detailed mechanisms is especially important in the design of new gas turbine combustion chambers and in the optimization of existing ones to improve efficiency and to reduce pollutant emissions, with fuel-flexibility and load-flexibility ever becoming more important. Different aspects of combustion processes where detailed reaction mechanisms provide useful insights will be covered in this paper: Fuels (alternative jet fuels, biomass based fuels), pollutants (soot), diagnostics (chemiluminescence), and thermochemistry. Furthermore, the underlying thermodynamics inevitably connected with detailed reaction schemes will be addressed. Exemplified results will be presented clearly demonstrating the predictive capabilities of detailed reaction mechanisms to be explored in computational fluid dynamic simulations to further optimize technical combustion systems.</p>

Ignition delay and chemical–kinetic modeling of undiluted mixtures in a high‐pressure shock tube: Nonideal effects and comparative uncertainty analysis

“…Furthermore, a series of undiluted IDT measurements of DME-air mixtures at lean, stoichiometric, and rich conditions is performed at the mean pressures listed in Table 4. 1 Note that for each measurement point, the measurement conditions are achieved behind a reflected shock wave, that is they cannot be set directly. Therefore, the measurement pressure varies slightly from measurement point to point and thus a mean pressure is provided.…”

“…Chemical-kinetic models describing hydrocarbon combustion are important to design and optimize combustion processes. 1 IDT represents one of the most important indirect experimental parameters used in combustion chemistry to validate and optimize detailed chemical-kinetic models due to its high sensitivity to major chain branching and termination reactions. Therefore, the fidelity and accuracy of such experimental data are essential.…”

Development of an Ethanol Combustion Mechanism Based on a Hierarchical Optimization Approach

“…Ignition delay times were measured in shock tubes, using mixture of O 2 with either Ar or Ne/Ar diluents [48][49][50][51][52][53][54][55] (φ = 0.25-2; conditions behind the reflected shock wave: p 5 = 0.2-16.9 atm and T 5 = 980-2222 K).…”

“…In other experiments [48][49][50][51][52][53][54][55], technical air was used to dilute ethanol (φ = 0.3-1.0, p 5 = 8.9-91.5 atm, T 5 = 778-1411 K). Time-to-ignition data measured in a rapid compression machine (RCM) were published by Mittal et al [12] (φ = 0.3, T c = 831-983 K, p c = 10-50 bar).…”