Anti-Erosion Mechanism Of Tamarix Chinensis And Its Biomimetic Application

Wear is one of the main reasons for failures of mechanical parts. In machineryindustry of china, about80%invalidation of components is caused by abrasion.Energy which is consumed by wear holds one third of total energy. Erosion is anattractive branch in the domain of wear. Erosion not only wastes energy largely, butalso consumes materials greatly, which reduces the operation efficiency of equipmentssharply and shortens the service life of components seriously. Erosion has brought greateffect to our production and life. Therefore, improving anti-erosion performance ofmaterials has become an urgent and important subject to the modern scholars.In the long term of evolvement, organisms have formed some special functions.By leaning and imitating these special functions, many important technique problemshad been solved effectively. In this paper, the bionic idea was used to improveanti-erosion performance of mechanical parts.In this paper, Tamarix chinensis was selected as the research object, which was atypical plant living in sandy deserts. It was found that Tamarix chinensis had excellentcharacteristics of windbreak and sand fixation by observing physiologicalcharacteristics of its flower, branch and leaf. The surface morphologies of Tamarixchinensis in vivo was studied by the use of stereomicroscope. Results showed that thesurface morphologies of Tamarix chinensis could effectively reduce body injurycaused by erosion and improve its anti-erosion performance. By leaning and imitatingthese surface morphologies, four kinds of bionic models were established, such assquare groove surface, v-groove surface, circular groove surface, convex surface.In order to study further anti-erosion performance of Tamarix chinensis, tensiletests along the grain were conducted in barks of Tamarix chinensis and Salixbabylonica. Test results showed that the bark of Tamarix chinensis was brittle material, but the bark of Salix babylonica was plastic material. Furthermore, elasticmodulus of Tamarix chinensis was higher than that of Salix babylonica. Then, erosiontests were conducted in barks of Tamarix chinensis and Salix babylonica by usingerosion test equipment. Test results showed that the maximum value of erosionweight loss of Salix babylonica was61.0mg, and the minimum value was24.1mg.However, the maximum value of erosion weight loss of Tamarix chinensis was only21.6mg. By analyzing results of tensile tests and erosion tests, it was found thatTamarix chinensis had better anti-erosion performance, and the anti-erosionmechanisms of Tamarix chinensis were discussed.Numerical simulations were conducted to predict the erosion performance of thesmooth sample and the grooved sample at30°,60°and90°inject angle respectivelyby the use of Fluent. At same time, the corresponding verification test was carried out.Results showed that their variation trends of the relative erosion rate were similar. Sothe use of calculation method and erosion model was correct in the process ofnumerical simulation. Then, numerical simulations were conducted to predict theerosion performance of four kinds of bionic models by using the same method andmodel. Results showed that the anti-erosion performance of four kinds of bionicmodels were as follows: the bionic model of v-groove surface> the bionic model ofcircular groove surface> the bionic model of square groove surface> the bionic modelof convex surface.In this paper, erosion characteristic for the impeller blades of centrifugal fan wasstudied on visualization. Based on the results of numerical simulation andvisualization research, three types of bionic blades were designed, such as the bionicblade of square groove surface, the bionic blade of v-groove surface and the bionicblade of circular groove surface. According to the experiment optimized technology,the experimental scheme was arranged. Erosion tests were conducted to predict theanti-erosion performance of bionic blades. The results of the range analysis showedthat the factors which influence the erosion weight loss in sequence were elementshape (A), distance (C), feature size (B). A had the greatest effect on the erosionresistance while B had the smallest. The optimum design parameters of bionic blades were as follows: v-groove surface, feature size of4mm, distance of2mm. Comparedwith smooth blades, the best combination of bionic blades could effectively improveanti-erosion performance of the impeller, which increased by28.97﹪.