Design Of Biomimetic Surfaces With Domes And Abrasive Behavior Against Water-sand Slurry

Abrasion of hydraulic machinery and pipeline against water-sand slurry is acommon phenomenon in industrial and agricultural production, resulting ininvalidation of hydraulic machinery parts and pipeline.In the conventional research of abrasive wear against two-phase flow withsand particles, less consideration of surface texture was taken as a factor affactingthe abrasive wear of the solid surfaces. In fact, the abrasive wear is affacted notonly by material itself but also by surface morphologies. Learning from themorphology of surfaces of the outside shell and fish scales, six kinds of biomimeticsurfaces with domes were designed.A liquid model was set up using software Pro/e wildfire 2.0. After dispersingthis model with the software Gambit, the numerical simulation was carried out insoftware Fluent for reversing engineering. A program for numerical simulationexperiments and analysis was developed. The developed program of simulationexperiments including design of single-factor experiment and orthogonalexperiment. It was shown from the results of the simulation experiments that fluxof the water-sand slurry and the sand particle diameter were the main factorsinfluencing the abrasive wear of the dome unit of the biomimetic surfaces.The material for the domes of the biomimetic surfaces was determinedthrough several tests. The material determined is the mixture of concrete of 75%wtand talcum powder of 25%wt. The domes made from the material can speed up theabrasive wear test procedure. The abraded volume of the domes on the biomimeticsurfaces was measured using LSV50 3-dimension laser scanning system and itssoftware imageware and software Pro/e wildfire2.0. The results showed that a goodprecision and recurrence in data. The experimental data was regressed by anorthogonal polynomial and the regressed equation of the abrasive wear volume y?of biomimetic surfaces with the flux of the water-sand slurry z1 and particlediameter z2 were found, that was: y? = ?7.42+8.685z1 +0.9254z2?0.165z1z2.The abrasive wear mechanisms of the domes of the biomimetic surfaces wereanalyzed. A new concept, Wear-Protecting Area, was put out. The abrasive wearphenomena of the domes of the biomimetic surfaces were explained by the weartheory about the abrasive wear of surfaces against water-sand slurry.The designing rules for biomimetic surfaces with domes have been foundthrough the theoretical analysis, numerical simulation and experiments of thebiomimetic surfaces. The design parameters were determined, that was as follows.(1) The thickness of the domes of the biomemitic surfaces was 1.4 mm.(2) V-angle of the front of the dome was 20-30 degree.(3) The optimal self-sharping angle of the domes was close to 90 degree,ensuring to keep smooth of the edges and the corners of the domes.(4) The optimal space span between two row domes was 20mm for thevelocity of the liquid of 1.169m/s to 1.7536m/s.(5) The arrangement of the domes of the biomimetic surfaces is catercornersimilar as the arrangement of the fish scales.