The use of porous coatings is one of the passive flow control methods used to reduce turbulence, noise and vibrations generated due to fluid flow. Porous coatings for flow stabilization have potential for a light-weight, cost-effective, and customizable solution. The design and performance of a structured porous coating depend on multiple control parameters like lattice size, strut thickness, lattice structure/geometry, etc. This study investigated the suitability of MSLA 3D printers to manufacture porous coatings based on unit cell designs to optimize porous lattices for flow control behind a cylinder. The Reynolds number used was 6.1×104–1.5×105 and the flow measurements were taken using a hotwire probe. Different experiment sets were conducted for single cylinder with varying control parameters to achieve best performing lattice designs. It was found that lattice structures with higher porosity produced lower turbulence intensity in the wake of the cylinder. However, for constant porosity lattice structures, there was negligible difference in turbulence and mean wake velocity levels. Coating thickness did not have a linear relationship with turbulence reduction, suggesting an optimal thickness value. For constant porosity coatings, cell count in coating thickness did not influence the turbulence or mean wake velocity. Partial coating designs like helical and spaced coatings had comparable performance to that of a full coating. MSLA printers were found capable of manufacturing thin and complex porous lattices.

The use of porous coatings is one of the passive flow control methods used to reduce turbulence and noise and vibrations generated due to fluid flow. A number of real-world applications rely on single or tandem cylinder systems like aircraft landing gears, chimneys, bridge pillars, etc. Using porous coatings for flow stabilization acts as a light-weight, cost-effective and customizable solution. The design and performance of a porous coating depend on multiple control parameters like lattice size, strut thickness, lattice structure, etc. This study aimed to investigate the suitability of MSLA 3D printers (Anycubic Photon and Prusa SL1) to manufacture porous coatings and to design and optimize porous lattices for flow control behind a cylinder. The Reynolds number used was 60000 and the flow measurements were taken using a hotwire probe. Different sets of experiments were conducted for single and tandem cylinder with varying control parameters to achieve the optimal lattice designs. The results show that the performance primarily depended on porosity, coating thickness, and coating shape. A high porosity thick coating gave a 70-75 % reduction in turbulence rate and also reduced the mean wake velocity. It was also seen that coating thickness is not linearly proportional to turbulence reduction and an optimal thickness exists for best performance.