Advancing CFD Approaches for Jet-Stirred Reactors

Efficient combustion processes are critical for optimizing fuel efficiency and minimizing emissions across various industries including transportation, manufacturing, and energy production. Hydrocarbon fuels account for 80% of global energy consumption. Despite advancements in alternative energy sources such as solar power and biofuels, hydrocarbons remain dominant due to their high energy density and established infrastructure. By using jet-stirred reactors (JSR), a subclass of continuous stirred tank reactors (CSTR), combustion kinetics can be studied through the alterations of various parameters such as pressure, temperature, and mixing conditions. JSRs are preferred for their efficient mixing capabilities and ability to accommodate exothermic reactions, making them ideal for investigating fuel-oxidizer interactions and reaction mechanisms. However, in addition to chemical kinetics and fluid flow dynamics, questions remain in understanding the optimal conditions for chemical and thermal homogeneity within these reactors. Temperature gradients and incomplete mixing can introduce uncertainties in current combustion studies, necessitating further refinement of numerical models. This study advances existing work that examined an initial condition of 300 K and 1 atm, along with various temperature and pressure boundary conditions in JSR simulations. Prior research demonstrated promising results when post-processing data at 1 atm, but due to a lack of experimental data at higher pressure, direct comparisons could not be made. Additionally, discrepancies were observed between reactor temperatures and wall temperatures, indicating potential thermal non-uniformities. This study seeks to further investigate these issues by extending computational analyses to higher system pressures and assessing the impact of elevated pressure on mixing efficiency and combustion kinetics. Using Computational Fluid Dynamics (CFD) with Ansys Fluent, this research will focus on refining existing simulations by evaluating the effects of temperature and pressure variations on flow behavior, turbulence, and thermal distribution. Special attention will be given to the secondary mixing region where chemical kinetics play a crucial role in reaction completion and product formation. The validated models will contribute to advancing CFD techniques in reactor engineering, benefiting fields such as chemical engineering, combustion research, and aerospace.