Abstract
A net immersed in fractal-induced turbulence exhibit a transient time-varying deformation. The anisotropic, inhomogeneous square fractal grid (SFG) generated flow interacts with the flexible net to manifest as visible cross-sectional undulations. We hypothesize that the net’s response may provide a surrogate in expressing local turbulent strength. This is analysed as root-mean-squared velocity fluctuations in the net, displaying intensity patterns dependent on the grid conformation and grid-net separation. The net’s fluctuation strength is found to increase closer to the turbulator with higher thickness ratio while presenting stronger fluctuations compared to regular-square-grid (RSG) of equivalent blockage-ratio, σ. Our findings demonstrate a novel application where 3D-reconstruction of submerged nets is used to experimentally contrast the turbulence generated by RSG and multilength scale SFGs across the channel cross-section. The net’s response shows the unique turbulence developed from SFGs can induce 9 × higher average excitation to a net when compared against RSG of similar σ.
Highlights
A net immersed in fractal-induced turbulence exhibit a transient time-varying deformation
We demonstrate the use of a flexible net submerged in a flow domain for a comparative study of turbulence generated using a regular square grid (RSG) as control and square fractal grids (SFG) by analysis of the net’s physical response
From the mean Vrms/Vref, one can infer that the turbulence induced by SFG6 and SFG8 interact with the net more strongly when it is closer to the turbulator while the turbulence does not show significant decay for the RSG and SFG5
Summary
A net immersed in fractal-induced turbulence exhibit a transient time-varying deformation. The net’s response shows the unique turbulence developed from SFGs can induce 9 × higher average excitation to a net when compared against RSG of similar σ. We demonstrate the use of a flexible net submerged in a flow domain for a comparative study of turbulence generated using a regular square grid (RSG) as control and square fractal grids (SFG) by analysis of the net’s physical response. A hexagonal celled polyester net secured in a thin rigid frame is placed at various distances streamwise from the tabulator This allows us to have a better comprehension of the cross-sectional turbulence strength at various distances from the grid.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
