Turbulence flow field in a four-fan stirred combustion furnace

This study comprehensively investigates the turbulence flow within a four-fan stirred combustion furnace using experimental and numerical approaches. To analyze the impact of turbulence on fuel combustion, a prerequisite is to accurately obtain the control rules before fuel combustion. This study established a high-frequency sampling method using a hot-wire anemometer to quickly test the homogeneous and isotropic turbulence (HIT) region and employing a continuous laser combined with a high-speed camera to achieve particle image velocimetry measurements of the central two-dimensional flow field. A steady simulation combining the realizable k–ε model with a multiple reference frame was performed to further analyze the three-dimensional flow field. The results show that the adopted method has high accuracy. Within a central spherical region of approximately 40 mm, the flow field exhibited HIT characteristics, with turbulent fluctuation velocity urms varying linearly with fan speed ω (urms = 0.000 814 ω). Integral eddy length remains around 14 mm, while smaller-scale Taylor and Kolmogorov eddy significantly decreased with increasing ω. Full-field simulations reveal that the highest turbulence kinetic energy occurred at the intersection of adjacent fan flows. Additionally, the study explored the effect of a 4 mm glass bead on flow field, revealing a rebound effect on mean velocity and a reduction in urms near the bead. The boundary layer thickness decreases at higher fan speed but remains on the order of particle radius 2 mm. These findings provide a foundation for future research on the role of turbulence lack of mean flow on combustion.