Preparation of a bionic lotus leaf microstructured surface and its drag reduction performance

Abstract

The bionic surface of the lotus leaf was prepared in large-area, and its drag reduction performance was studied by both numerical simulation and experimental analysis.

Effective Underwater Drag Reduction: A Butterfly Wing Scale-Inspired Superhydrophobic Surface

“…The BWSLS exhibits a high drag reduction rate at moderate flow velocities and Reynolds numbers. Notably, the BWSLS shows a significant improvement in the drag reduction rate of approximately 3–18% as compared to those of other biomimetic surfaces. − ,− The maximum drag reduction rate of 20.25% achieved by the BWSLS exceeds the conventional single-groove surface ,,, and CAS ,,− with a maximum optimized drag reduction rate of 18.76% . In contrast to the single-structured surfaces, the hierarchical structure of the BWSLS consisting of ridges and pores can capture large gas amounts, effectively reducing the velocity gradient near the wall and viscosity of the gas–liquid two-phase flow, thereby enhancing the interfacial slip and increasing the drag reduction efficiency.…”

Bionic structures for optimizing the design of stealth materials

“…Plants in nature generally have special structures, such as the micro-nano composites on the surface of lotus leaves and nepenthes. [38][39][40][41] These kinds of structures have special scales and combinations of different scales, and some of the synergies between them will generate special effects. Therefore, a reasonable design of bionic hierarchical composites may also be an effective method to optimize the microwave absorption performance.…”

Bionic research on Paramisgurnus dabryanus scales for drag reduction

“…PDMS is usually a colorless liquid with high viscosity, which can be cured at a certain temperature after reacting with the curing agent. The preparation process of the flexible bionic surface was the followings: 32 (i) an appropriate amount of dry release agent was sprayed on the surface of the aluminum substrate mold; (ii) the mixture of liquid PDMS and curing agent with a mass ratio of 10 : 1 was magnetically stirred for 15 min; (iii) the mixture was put into a vacuum drying oven and vacuumized repeatedly for 20 min, and the degree of vacuum was kept at −100 kPa to remove the bubbles existing in the solution; (iv) the mixture was slowly poured into the center of the aluminum substrate until the mold was filled, and the excess material was scraped off to ensure that the top surface was horizontal; (v) the mold with the PDMS cast was placed in a drying oven and cured at 80 °C for 8 h; (vi) demoulding carefully and cleaning the samples.…”