Abstract
Dynamic response of the fluid force acting on an axially oscillating radial impeller was numerically investigated. The impeller of a rocket engine turbopump was modeled to oscillate in the axial direction. The flow field around the impeller was divided into front and back clearance between rotor and casing, and each flow field was simulated using unsteady CFD simulation changing the oscillating frequency. From the fluid force of the simulation results, dynamic haracteristic coefficients, i.e., m, k, c, were calculated and compared between front and back shroud. It was found that the dynamic characteristic coefficients of fluid force acting on the front shroud were much smaller than back ones with balance piston.
