The paper presents a procedure for hydraulic design and analysis of the blade geometry of a high specific speed runner of the Saxo-type double-regulated vertical axial turbine. The meridional through-flow in the passage from the conical guide vane apparatus to the draft-tube elbow is designed by a streamline curvature method (SCM). To validate the design method and predictions and to investigate the design duty point and a number of off-design operating regimes, an extensive CFD simulation inside the entire turbine water-passage is performed. The flow patterns downstream the guide vane apparatus and the runner exit flow are analyzed. The focus of the analysis is on distribution of the angular momentum alongside the turbine, as well as on its impact on the flow around the runner blades. The SCM design procedure presented in the paper proves to be a robust and accurate tool for the runner blade row design.
COBISS.SI-ID: 11820315
The main goal of the paper is to enlighten some of the most important design, hydraulic and economic advantages of the Saxo-type turbines and consequently to initiate professional discussion which may point out drawbacks of these turbines as seen by European market. Special attention is drawn on description of the Saxo turbine and its main differences comparing to tubular and Kaplan type turbines. In addition are described some main issues of theoretical and numerical investigations of the flow field in the intake elbow, distributor, runner regions and draft tube.
COBISS.SI-ID: 1024062812