Effect of bionic blade surface on performance improvement of paddy field impeller

Inspired by the geometric structure of the bamboo culm sheath and the surface topology of the dung beetle, a bionic blade for a paddy field impeller was developed to enhance soil cultivation efficiency in rice plantations. The blade surface was modified by using laser-texturing with a macro-scale design to reduce soil resistance. Computational Fluid Dynamics simulations revealed a 47.10% increase in fluid velocity and a 46.87% reduction in drag force compared to conventional curved blades. In soil bin tests, the bionic blade demonstrated a 10.26% reduction in driving torque and an 11.32% increase in rotational speed due to decreased soil cutting resistance. Further investigation of the rotor's 190 mm and 210 mm sinkage depths highlighted the design's effectiveness. The improved performance is attributed to reduced blade contact area and lower soil resistance in wet conditions. Surface treatments, including gas carburizing, case hardening, tempering, and epoxy cathodic electrodeposition coating, significantly enhanced the mechanical properties of the bionic blade, improving hardness, tensile strength, and corrosion resistance. This integration of bionic design and surface engineering offers a significant performance improvement for paddy field impellers, contributing to advancements in agricultural machinery for rice cultivation.