Effect Of Sediment-water Mixtureon Cavitation Erosion And Abrasive Wearof Metal Material

Damage caused by cavitation erosion and abrasive wear is bad to hydraulic machineryin the river with high concentration sediment.this paper uses a vibrating probe to match acustom-made particle-moving device for the experiment research of cavitation erosion and abrasive wear by combining to reveal the actual influence of sediment oncavitation and erosion basis abrasive wearof45~#carbon steel and for building sediment prediction model.In this paper,we consider many factors including sediment particle size and concentration,viscosity and aeration and so on.The main research results are as follows:(1)Research of equipment.According to the test requirements,we design the particle-moving device which can be better used to the vibrating probe for testof cavitation erosion and abrasive wear.The sediment-water mixture with concentration of 300 kg/m~3 still can use normally and we give a detailed operating instruction.(2)Test ofsingle particle size of sediment.The results show that the amount of damage increases first slowly and then increases abruptly as the test progresses.The critical particle size of sediment is indeed present and the critical particle size is given in the range of 0.045mm-0.062mm.It is found that the size of the critical particle size is related to the sediment concentration and varies slightly in this interval.When the particle size of sediment is less than the critical particle size.The damage is less than that of tap water and the damage decreases with the increase of sediment concentration.When the particle size is larger than the critical particle size,the damage increases with the increase of sediment concentration and the increasing amplitude gradually decreased.(3)The sediment critical concentration and the aeration cavitation research.When the sediment concentration increases from low lever to high,the damage does not increase linearly,but it increases with the increase of sediment concentration and reaches a certain critical value that we think it is 12kg/m~3.When the sediment concentration increases,the damage decreases and gradually decreases with the increase of the sediment is gradually stable.During the experiment,it was found that the rotation speed of the blades was increased,the water of aeration amount is larger.It is very significant of the damage reduction(4)Mixture of two sizes of sediment.The damage characteristics of the two types of particles that is mixed with the particle size less than the critical particle size are the same as those of the single particle size sediment.The results show that with the increase of the sediment concentration,the damage is decreases,The damage characteristics of the two kinds of sediment particles are the same as those of the single particle coarse sediment.It is found that when the sediment concentration is small,the abrasive characteristics of the fine-particles sediments are similar to those of the tap water.With the increase of the sediment concentration,it is gradually showing the damage characteristics of coarse sediment.The damage increased gradually.