Theoretical and numerical investigation on the EDC-model for turbulence–chemistry interaction at gasification conditions

Rehm, Markus; Seifert, Péter; Meyer, Bernd

doi:10.1016/j.compchemeng.2008.11.006

Cited by 83 publications

(57 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their analysis showed that Eddy Dissipation Concept (EDC) combustion model in conjunction with a skeletal chemistry mechanism reasonably well predicted the axial profiles of mean temperature and species concentration in the flue gas while compared to experimental values. The EDC model has been applied in modeling of gasification by Rehm et al [28]. They reported that for this system with relatively slow reactions, model adjustments were necessary.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

Oldenhof

Sathiah

et al. 2011

Flow Turbulence Combust

181

173

View full text Add to dashboard Cite

In this paper, we report results of a numerical investigation of turbulent natural gas combustion for a jet in a coflow of lean combustion products in the Delft-Jet-in-Hot-Coflow (DJHC) burner which emulates MILD (Moderate and Intense Low Oxygen Dilution) combustion behavior. The focus is on assessing the performance of the Eddy Dissipation Concept (EDC) model in combination with two-equation turbulence models and chemical kinetic schemes for about 20 species (Correa mechanism and DRM19 mechanism) by comparing predictions with experimental measurements. We study two different flame conditions corresponding to two different oxygen levels (7.6% and 10.9% by mass) in the hot coflow, and for two jet Reynolds number (Re = 4,100 and Re = 8,800). The mean velocity and turbulent kinetic energy predicted by different turbulence models are in good agreement with data without exhibiting large differences among the model predictions. The realizable k-ε model exhibits better performance in the prediction of entrainment. The EDC combustion model predicts too early ignition leading to a peak in the radial mean temperature profile at too low axial distance. However the model correctly predicts the experimentally observed decreasing trend of lift-off height with jet Reynolds number. A detailed analysis of the mean reaction rate of the EDC model is made and as possible cause for the deviations between model predictions and experiments a low turbulent Reynolds number effect is identified. Using modified EDC model constants prediction of too early ignition can be avoided. The results are weakly sensitive to the sub-model for laminar viscosity and laminar diffusion fluxes.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

Oldenhof

Sathiah

et al. 2011

Flow Turbulence Combust

181

173

View full text Add to dashboard Cite

show abstract

“…According to the implementation of the EDC model in the CFD code, it was notable that the expression , as shown in Magnussen's original expression of formulas (10) and (11), was set to unity as proposed by Rehm et al [27]. Figure 3 shows a sequence of high-speed images of flame propagation during the course of explosions, as the CH 4 /air premixed gas concentration was 9.5% ( = 1).…”

Section: Edc Modelmentioning

confidence: 99%

“…Realizable -model was substantially superior to the standard -model in many applications, which generally brought forth much more accurate data [24]. As a compromise of accuracy and computational time cost, the EDC was successfully applied in different regimes of combustion [25][26][27] by using detailed reaction mechanism.…”

Section: Introductionmentioning

confidence: 99%

“…In combustion simulation, the physical and chemical processes were of great importance, both of which acted in vastly different time scales; moreover, the chemical process covered the entire time scales of the physical process [27]. The eddy dissipation concept (EDC) model with an extension of eddy-dissipation model and detailed chemical mechanisms in turbulent flows was included.…”

Section: Edc Modelmentioning

confidence: 99%

See 1 more Smart Citation

Premixed CH₄-Air Flame Structure Characteristic and Flow Behavior Induced by Obstacle in an Open Duct

Chen

Zhang

et al. 2014

Advances in Mechanical Engineering

View full text Add to dashboard Cite

To study the fuel gas combustion hazards, the methane/air flame structure and flow characteristic in an open duct influenced by a rectangular obstacle were explored by experiment and realizable -model (RKE). In the test, the high-speed schlieren photography technology and dynamic detection technology were applied to record the flame propagation behavior. Meanwhile, the interaction between flame front and flame flow field induced by the obstacle was disclosed. In addition, the laminar-turbulence transition was also taken into consideration. The RKE and eddy dissipation concept (EDC) premixed combustion model were applied to obtain an insight into the phenomenon of flow change and wrinkle appearing, which potently explained the experimental observations. As a result, the obstacle blocked the laminar flame propagation velocity and increased pressure a little in an open duct. Some small-scale vortices began to appear near the obstacle, mainly due to Kelvin-Helmholtz instability (KHI), and gradually grew into large-scale vortices, which led to laminar-turbulent transition directly. The vortices thickened the reaction area and hastened the reaction rate; reversely, the higher reaction rate induced larger vortices. The RKE model result fitted the test data well and explained the wrinkle forming mechanism of two special vortices in the case.

show abstract

“…We know that the EDC model may be influenced by the mixing conditions: mixing time and the fine scale fraction at the cell level. We know that specific works show the influence of this effect 30 , but our goal is to evaluate, at this step, the limits and needs of classical computing schemes.…”

Section: Mathematical Modelmentioning

confidence: 99%

2D Axisymmetric Coupled Computational Fluid Dynamics–Kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel Reforming

2011

View full text Add to dashboard Cite

The present study is dedicated to the coupled CFD-kinetics 2D axisymmetric modeling of plasma-assisted diesel fuel reformer developed for two different applications: (i) onboard H 2 production for fuel cell feeding and (ii) NO x trap regeneration. These cases correspond to very different reacting conditions. In the first case, diesel fuel reacts with air while in the second case it reacts with diesel engine exhaust gas. The plasma is modeled with a simple power source domain. n-heptane has been chosen as a surrogate molecule for diesel fuel. A reduced kinetic mechanism is used for the study. Both cases have been studied under adiabatic and nonadiabatic postreactor conditions. We can distinguish four zones in the torch: a reactant heating zone, a plasma zone, a mixing zone and a postdischarge zone. The main precursors of the reforming reactions are H, O and OH radicals. The oxygen rate is a key point of the application. The thermal losses make the reforming reaction difficult to ignite and beget a lower syngas production and a lower postdischarge temperature. For the nonadiabatic reactor, the results have been compared to experimental data. The model predicts relevant gas fractions.2

show abstract

Theoretical and numerical investigation on the EDC-model for turbulence–chemistry interaction at gasification conditions

Cited by 83 publications

References 11 publications

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

Premixed CH₄-Air Flame Structure Characteristic and Flow Behavior Induced by Obstacle in an Open Duct

2D Axisymmetric Coupled Computational Fluid Dynamics–Kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel Reforming

Contact Info

Product

Resources

About

Theoretical and numerical investigation on the EDC-model for turbulence–chemistry interaction at gasification conditions

Cited by 83 publications

References 11 publications

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

Premixed CH4-Air Flame Structure Characteristic and Flow Behavior Induced by Obstacle in an Open Duct

2D Axisymmetric Coupled Computational Fluid Dynamics–Kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel Reforming

Contact Info

Product

Resources

About

Premixed CH₄-Air Flame Structure Characteristic and Flow Behavior Induced by Obstacle in an Open Duct