Analysis of Head Loss in Pipes with Multiple Bends

Abstract

This study investigates the influence of pipe bend spacing on head loss in NPS 2-inch pipes equipped with multiple 90° elbows, a common configuration in compact pipeline systems. Three configurations were examined, where the spacing between consecutive bends was set at 200 mm, 300 mm, and 500 mm, respectively, to assess the impact on flow behaviour and energy losses. Numerical simulations were carried out using ANSYS Fluent, assuming fully turbulent flow with a Reynolds number of approximately 52,000. The k-ω SST turbulence model was applied to capture detailed flow dynamics, including turbulence intensity, pressure distribution, velocity profiles, and energy dissipation mechanisms. A grid independence test was conducted to ensure numerical accuracy, stability, and convergence, validating the chosen mesh size for efficient computational performance. The results revealed that smaller bend spacing significantly increases turbulence kinetic energy (TKE) and pressure losses. Specifically, the 200 mm configuration produced the highest TKE and exhibited an average head loss approximately 18% higher than the 500 mm configuration, with a maximum pressure drop of 312.33 Pa. In contrast, the 500 mm spacing allowed for more uniform flow, reduced turbulence intensity, lower pressure losses, and improved energy efficiency, while the 300 mm configuration showed intermediate behaviour. These outcomes indicate a clear relationship between bend spacing and hydraulic performance, emphasizing that insufficient spacing can lead to higher energy consumption, excessive pressure drops, and reduced pipeline efficiency. The findings provide critical insights for the design and optimization of pipeline systems in industrial applications, particularly where space constraints necessitate multiple bends, guiding engineers to balance compactness with hydraulic performance to achieve efficient, reliable, and cost-effective flow systems.