Turbulent Flow Characterization of a Fan-stirred Constant Volume Combustion Chamber Using Large Eddy Simulation

Understanding turbulent premixed flame propagation under engine-relevant conditions is crucial for advancing efficient combustion technologies. This study applies high-fidelity Large Eddy Simulation (LES) to support the design and optimization of a fan-stirred constant volume combustion chamber intended for future experiments on spherically propagating turbulent premixed flame propagation. The numerical analysis focuses on accurately resolving the incompressible, isothermal, transient flow field generated by six rotating fans operating at two different rotation speeds, aiming to achieve high turbulence intensities with minimal mean flow in the optical measurement region. The LES results indicate that the flow field generated in the targeted region is statistically stationary, spatially homogeneous, and nearly isotropic. Moreover, the computed turbulence intensities and integral length scales are in close agreement with target values representative of large-bore internal combustion engines. These findings confirm the viability of the proposed design for future experimental investigations of flame–turbulence interactions of different fuels under engine-like operating conditions.