Modelling of Spray Flames with Doubly Conditional Moment Closure

Area of Science:

• Combustion Science
• Chemical Engineering
• Computational Fluid Dynamics

Background:

• Spray combustion simulations require accurate modeling of complex phenomena like droplet evaporation and differential diffusion.
• Existing models may not fully capture the interplay between turbulence, chemistry, and spray dynamics.

Purpose of the Study:

• To derive and apply a Doubly Conditional Moment Closure (DCMC) model for simulating pilot-stabilised ethanol spray flames.
• To assess the significance of various terms within the DCMC framework for spray combustion.

Main Methods:

• Development of a DCMC equation incorporating droplet evaporation and differential diffusion using mixture fraction and reaction progress variable.
• Implementation of closure sub-models for Favre-averaged spray terms.
• Validation against experimental data for a pilot-stabilised ethanol spray flame.

Main Results:

• The DCMC model successfully simulates the ethanol spray flame.
• The study provides insights into the importance of different physical and chemical terms in the model.
• Promising overall agreement between simulation results and experimental data was achieved.

Conclusions:

• The DCMC model offers a viable approach for simulating ethanol spray combustion.
• Further refinement of sub-models may improve accuracy and address discrepancies with experimental data.