Calculating Speed Profile and Hydraulic Resistance Based on Fixed Parameters in a Smooth Pipe and Testing in Ansys Fluent

The article examines the mutually consistent calculation of local velocities, hydraulic resistance coefficients, and head losses when the parameters of the logarithmic velocity profile in a smooth pressure pipeline are assumed to be constant across the cross-section. Empirical expressions of the Karman parameter κ and the free term C1 depending on λ were analyzed. When converting the implicit equation determining the resistance coefficient to the Reynolds number, an algebraic inconsistency with respect to the constant term was determined, and the corresponding form was substantiated. An algorithm for the iterative determination of water discharge capacity has been developed. In the conditional example with D=1 m and Q=31.4 m3/s, the sensitivity to velocity and erosion intensity near the rim of the ring was evaluated. To fully verify the risk of cavitation, a mixture multiphase model, a Zwart–Gerber–Belamry or Schnerr–Sauer cavitation model, and a methodology for assessing local pressure and the proportion of vapor phase in ANSYS Fluent were proposed.