engleski

Automatized Procedure for Calculation of Laminar Flame Speed and Autoignition Data Bases in Coherent Flame Models

The impact of the transport sector on climate change and carbon dioxide emissions into the atmosphere can be decreased by the utilization of biofuels and e-fuels. Numerous biofuels and e- fuels are currently available, where each fuel features different physical properties, chemistry kinetics, and combustion characteristics. The chemical kinetics for calculating their combustion process is often excessively computationally demanding for numerical simulations, leading to the development and employment of combustion models, such as coherent flame models. In this work, the coherent flame models were employed for which the ignition delay and laminar flame velocities for different operating conditions are required to be precalculated in the form of a database or correlation formula. Developed procedure scrutinize available reaction mechanisms of several fuels with the validation against existing experimental data of autoignition and laminar flame velocities, aiming for the generation of look-up databases. The autoignition of fuel/air mixtures for different conditions is pre-tabulated from 0D constant pressure reactor calculation. Simultaneously, the laminar flame speed is pre-tabulated from premixed freely propagating reactors, for which the LOGE™ software was used. The ignition delay of cold flame and primary ignition was calculated using inflection point criteria implemented in the proposed method. The developed imputations methods and correlation functions are based on the lognormal distribution for laminar flame speed in equivalence ratio direction and exponential functions for pressure, temperature, and exhaust gas recirculation directions. Additionally, the method is also applicable to dual-fuel combustion. The ignition delay and laminar flame speed values of fuel blends are described with the additional parameter of the fuel composition. Finally, the database implementation into the computational fluid dynamics software is presented, verified with the detailed chemical mechanism of e-fuel three- oxyethylene ether (OME-3) fuel.

Autoignition ; laminar flame speed ; tabulation ; chemical kinetics ; combustion ; e-fuels

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