A Comparative Study of LES Turbulent Combustion Models Applied to a Low Swirl Lean Premixed Burner

2008 ◽  
Author(s):  
Karl Nogenmyr ◽  
Xue Bai ◽  
Christer Fureby ◽  
Per Petersson ◽  
R. Collin ◽  
...  
Keyword(s):  
Comparative Study ◽  
Turbulent Combustion ◽  
Combustion Models ◽  
Lean Premixed

A lagrangian based scalar pdf method for turbulent combustion models

2004 ◽  
Vol 18 (8) ◽  
pp. 1470-1478 ◽  
Author(s):  
Hee-Jang Moon ◽  
Roland Borghi
Keyword(s):  
Turbulent Combustion ◽  
Combustion Models

Numerical Simulation of Turbulent Combustion Flows for Coaxial Jet Cluster Burner

2013 ◽  
Author(s):  
Keita Yunoki ◽  
Tomoya Murota ◽  
Keisuke Miura ◽  
Teruyuki Okazaki
Keyword(s):  
Turbulent Combustion ◽  
High Efficiency ◽  
Premixed Combustion ◽  
Premixed Flame ◽  
Gas Temperature ◽  
Lean Premixed Combustion ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Lean Premixed ◽  
Multiple Holes

We have developed a burner for the gas turbine combustor, which was high efficiency and low environmental load. This burner is named the “coaxial jet cluster burner” and, as the name indicates, it has multiple fuel nozzles and holes in a coaxial arrangement. To form lean premixed combustion, this burner mixes fuel and air in the multiple holes rapidly. The burner can change the combustion form between premixed and non-premixed combustion by controlling the mixing. However, the combustion field coexisting with premixed and non-premixed combustion is complicated. The phenomena that occur in the combustion field should be understood in detail. Therefore, we have developed the hybrid turbulent combustion (HTC) model to calculate the form in which non-premixed flame coexists with premixed flame. Turbulent flow has been simulated using a large eddy simulation (LES) with a dynamic sub grid scale (SGS) model coupled with the HTC model. These models were programmed to a simulation tool based on the OpenFOAM library. However, there were unclear points about their applicability to an actual machine evaluation and the predictive precision of CO concentration which affects burner performance. In this study, we validate the HTC model by comparing its results with measured gas temperature and gas concentration distributions obtained with a coaxial jet cluster burner test rig under atmospheric pressure. In addition, we analyze the CO generation mechanism for the lean premixed combustion in the burner.

Assessment of Turbulent Combustion Models for Simulating Pre-Chamber Ignition in a Natural Gas Engine

2021 ◽  
Author(s):  
Joohan Kim ◽  
Riccardo Scarcelli ◽  
Sibendu Som ◽  
Ashish Shah ◽  
Munidhar Biruduganti ◽  
...  
Keyword(s):  
Natural Gas ◽  
Turbulent Combustion ◽  
High Efficiency ◽  
Turbulent Flame ◽  
Spark Ignition ◽  
Cylinder Wall ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Combustion Models ◽  
Combustion Processes

Abstract Lean combustion in an internal combustion engine is a promising strategy to increase thermal efficiency by leveraging a more favorable specific heat ratio of the fresh mixture and simultaneously suppressing the heat losses to the cylinder wall. However, unstable ignition events and slow flame propagation at fuel-lean condition lead to high cycle-to-cycle variability and hence limit the high-efficiency engine operating range. Pre-chamber ignition is considered an effective concept to extend the lean operating limit, by providing spatially distributed ignition with multiple turbulent flame-jets and enabling faster combustion rate compared to the conventional spark ignition approach. From a numerical modeling perspective, to date, still the science base and available simulation tools are inadequate for understanding and predicting the combustion processes in pre-chamber ignited engines. In this paper, conceptually different RANS combustion models widely adopted in the engine modeling community were used to simulate the ignition and combustion processes in a medium-duty natural gas engine with a pre-chamber spark-ignition system. A flamelet-based turbulent combustion model, i.e., G-equation, and a multi-zone well-stirred reactor model were employed for the multi-dimensional study. Simulation results were compared with experimental data in terms of in-cylinder pressure and heat release rate. Finally, the analysis of the performance of the two models is carried out to highlight the strengths and limitations of the two formulations respectively.

Comparison of Combustion Models in Cleanroom Fire

2008 ◽  
Vol 24 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Y.-L. Huang ◽  
H.-R. Shiu ◽  
S.-H. Chang ◽  
W.-F. Wu ◽  
S.-L. Chen
Keyword(s):  
Turbulent Combustion ◽  
Global Radiation ◽  
Turbulence Models ◽  
Fire Simulation ◽  
Smoke Control ◽  
Radiation Model ◽  
Combustion Models ◽  
Radiation Heat Exchange ◽  
Computational Fluid Dynamics Cfd ◽  
Combustion Processes

AbstractIn this paper, the cleanroom fire simulation in a semi-conductor factory is investigated by using the commercial computational fluid dynamics (CFD) code. We using three different combustion models in the fire simulation. The combustion models including the volume heat source (VHS) model, the eddy break-up (EBU) model and the presumed probability density function (prePDF) model are considered to predict the cleanroom fire. The turbulence models coupled with different combustion models, while the radiation model is coupled with the turbulent combustion processes. Additionally, the discrete transfer radiation method (DTRM) is used in the global radiation heat exchange. For the fire simulation, the different combustion models are evaluated for their performance and compared with the experimental data from the literature to verify. Thus, these numerical simulations can be adopted as a useful tool to design and optimize the smoke control strategy in cleanroom fire.

Assessment of Turbulent Combustion Models for Simulating Pre-Chamber Ignition in a Natural Gas Engine

2019 ◽  
Author(s):  
Joohan Kim ◽  
Riccardo Scarcelli ◽  
Sibendu Som ◽  
Ashish Shah ◽  
Munidhar S. Biruduganti ◽  
...  
Keyword(s):  
Natural Gas ◽  
Turbulent Combustion ◽  
High Efficiency ◽  
Turbulent Flame ◽  
Spark Ignition ◽  
Cylinder Wall ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Combustion Models ◽  
Combustion Processes

Abstract Lean combustion in an internal combustion engine is a promising strategy to increase thermal efficiency by leveraging a more favorable specific heat ratio of the fresh mixture and simultaneously suppressing the heat losses to the cylinder wall. However, unstable ignition events and slow flame propagation at fuel-lean condition lead to high cycle-to-cycle variability and hence limit the high-efficiency engine operating range. Pre-chamber ignition is considered an effective concept to extend the lean operating limit, by providing spatially distributed ignition with multiple turbulent flame-jets and enabling faster combustion rate compared to the conventional spark ignition approach. From a numerical modeling perspective, to date, still the science base and available simulation tools are inadequate for understanding and predicting the combustion processes in pre-chamber ignited engines. In this paper, conceptually different RANS combustion models widely adopted in the engine modeling community were used to simulate the ignition and combustion processes in a medium-duty natural gas engine with a pre-chamber spark-ignition system. A flamelet-based turbulent combustion model, i.e., G-equation, and a multi-zone well-stirred reactor model were employed for the multi-dimensional study. Simulation results were compared with experimental data in terms of in-cylinder pressure and heat release rate. Finally, the analysis of the performance of the two models is carried out to highlight the strengths and limitations of the two formulations respectively.

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