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

This paper describes an approach to modeling the flow velocity distribution at the inlet of a hydro turbine draft tube that can significantly reduce test costs. The flow is modeled using a special apparatus consisting of a combination of two swirlers: fixed and rotating. A 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 arrays modeling the velocity distributions in optimal operating modes of hydro turbines of various types. This paper presents a test numerical calculation of flow parameters using the Ansys program and a comparison of the designed velocity distributions with experimental velocity profiles obtained on an aerodynamic rig using a laser Doppler anemometer. The design, calculated, and experimental velocity profiles at the draft tube inlet are in satisfactory agreement. Thus, the promising approach to the experimental modeling of the hydro turbine flow was successfully tested.