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The computational accuracy for sediment erosion numerical simulation of double suction centrifugal pump is influenced by solid-liquid two phase flow algorithm. The modified Eulerian algorithm for solid-liquid two-phase flow was adopted, both characteristics of inter-phase drag force and sediment diffusion coefficient were considered in the modified algorithm. Then the flow field of double suction centrifugal pump was simulated for typical suspended load sediment particle diameters. The results showed that the turbulence intensity on the front and back of blade were greater, which were 6%~10%. The particle dynamic scales were greater on the front and back of blade rather than on the middle of the blade in consideration of the location. The turbulence scale effect was composed of the turbulence intensity and the particle dynamic scale. The turbulence scale effect gave more obvious influence on the front and back of blade rather than on the middle of the blade. The particles were easier to diffuse because of the increasing inter-phase drag force led by the turbulence scale effect, the particles gathering phenomenon was then avoided. The turbulence scale effect gave more obvious influence on large particles rather than on small particles in consideration of the particles scale. So interval range between maximum value and minimum value of the calculated solid concentration distributions on blade pressure surface was decreased. The calculated solid volume fraction had larger variation for the large particles than the small particles, and larger variation on the front and back of blade than the middle of blade, because turbulence scale effect was considered. The block erosion area located in blade pressure surface trailing edge was severe erosion area, the result calculated by the modified algorithm was agreed well with the actual erosion conditions of centrifugal pump rather than the results of the zonary erosion area and partial erosion area calculated by traditional algorithm. There was an increase in the erosion ratio with the turbulence scale effect considered. Then on this basis, the principles of the blade hydraulic design and the blade surface spraying protection for double suction centrifugal pump were proposed. The principles laid the foundation for improving abrasion resistance of double suction centrifugal pump.