Approach to the laboratory modeling of the flow velocity distribution behind hydro-turbine runner 2. verification of the method

This paper describes an approach to modeling the flow velocity distribution at the inlet of the hydro turbine draft tube that can significantly reduce test costs. The flow is modeled using a special swirler consisting of a combination of two blade rows: fixed and rotating. The previously proposed method for designing swirlers to generate velocity fields corresponding to the velocity distributions behind real hydro turbines was used to design eight blade rows modeling the velocity distributions in optimal operating modes of hydro turbines of various types. This paper presents a test numerical calculation of the flow parameters using Ansys code and a comparison of design velocity distributions with experimental velocity profiles obtained on an aerodynamic rig using a laser Doppler anemometer. The design, calculated, and experimental flow velocity profiles at the draft tube inlet are shown to be in satisfactory agreement. Thus, the promising approach to the experimental modeling of hydro turbine flow was successfully tested.