Estimation Methodology of Pressure Losses in Non-circular Pipes

The article presents a methodology for determining the hydraulic resistance multiplier, used for a rapid estimation of linear losses in pipes with non-circular cross-sections. The numerical approach was applied using the Finite Volume Method and the ANSYS Fluent software. The research was conducted under turbulent flow conditions, covering two Reynolds number ranges: 10,000 to 100,000 (10 cases) and 100,000 to 1,000,000 (5 cases). The first section of the article presents calculations of losses for a circular pipe, accompanied by a mesh test and error estimation. The second section includes calculations conducted for a series of pipes with various selected cross-sectional shapes: half-circle, quarter-circle, square, rectangles with aspect ratios of 2:1 and 3:1, isosceles triangle, and equilateral triangle. The last section of the article discusses the calculation of linear losses and the hydraulic resistance multiplier for each tested shape. It was found that this coefficient ranged from 1.33 to 2.2, depending on the shape, with the influence of the Reynolds number being relatively insignificant.