The RANS governing equation and RNG k-εturbulence model are used,the flow fields at different relative positions between blade and volute tongue in a centrifugal pump are simulated using finite volume method,under the hypothesis of steady flow,the regularities of computation errors of each performance parameter are analyzed in accordance with the relative positions.Through the comparisons of mean squared deviation of each performance parameter at different relative position,it is found that there is a suita...