An Analytic Method of Calculating the Spirals of the Turbine Pits of Hydraulic Turbines Based on Different Laws of Variation of the Average Circumferential Velocity in Cross-Sections Along the Length of the Spiral

Abstract

A new method of calculating the turbine spiral pits of hydraulic turbines with round cross-sections is proposed. The method generalizes techniques that are used today for determining the circular cross-sectional areas of a spiral with assigned or adopted area of its input cross-section. Any laws of variation of the average circumferential velocities in the cross-sections along the length of the spiral may be adopted in the method, which substantially expands the range of methods currently employed. By means of the method the dimensions of round and elliptical cross-sections of a spiral in the tooth region with the widely used conical scheme of coupling of its metal shell with the stator of the hydraulic turbine may be precisely determined.