Numerical investigation for centrifugal impeller with load blade

摘要

The flow inside a centrifugal impeller with load blade at design and off-design point conditions is numerically investigated by solving the three-dimension Navies-Stokes equation couple with the Spalart-Allmaras turbulence model. The numerical results are obtained at off-design and design flow rate. The distributions of blade loading were predicted at mid-span, near hub and near shroud. Computational results show that The load blade makes the blade loading and the main diffusion region concentrating on the after part of blade and formation of positive pressure region near suction side of blade. These effects can weaken the influence of secondary, thin the boundary layer and depress the separation of boundary layer. Computation results about efficiency and pressure ratio agree well with experimental results. It is suggest that the blade loading move to the after part of blade when aerodynamic design for impeller is performing.