Reducing honeycomb-generated turbulence with a passive grid

Abstract Honeycombs are widely used to laminarize fluid streams by inhibiting the lateral components of fluctuating velocity. However, they also produce additional turbulence themselves due formation large-scale instabilities and breakup individual velocity profiles stemming from honeycomb cells. In present research, we use 2D-planar particle image velocimetry study how honeycomb-generated is affected a downstream grid. It found that placing grid near discharge drastically enhances flow uniformity separating strong jets cells into many smaller much more rapidly dissipated. The results show using reduces integral length scale up factor 10, axial energy spectra reveal primarily limits contained in eddies with lower wave numbers. Furthermore, can reduce magnitude peak intensity as 95% leads large reduction correlation length, long it positioned upstream onset honeycomb-induced instabilities. A highly beneficial for both laminar turbulent most effective when there slight offset between honeycomb. Even though longer honeycombs generally than short ones larger length-scale shear layers, these effects almost entirely decoupled honeycomb-grid combination. Finally, combination effectively inhibits turbulence. Graphic abstract