International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 12 Issue: 08 | Aug 2025
p-ISSN: 2395-0072
www.irjet.net
Experimental and CFD Analysis Based Design of Additively Manufactured Stepped Spillway for Open Channel Flow Experiments Dr. Fayyaz Rehman1, Robert Benham2 1Associate Professor, Department of Science and Engineering, Southampton Solent University, Southampton, UK 2Senior Lecturer, Department of Engineering, Computing and Mathematics, University of Chichester, Chichester,
UK ---------------------------------------------------------------------***--------------------------------------------------------------------engineering history, with archaeological and textual Abstract – Additive Manufacturing (AM) is emerging as a
records indicating their use in structures dating back more than three thousand years [3]. These early designs, often constructed from stone masonry, reveal an enduring understanding of the need to control hydraulic energy for the protection of downstream channels. Contemporary stepped spillway research builds upon this ancient foundation, shifting the focus from empirical observation to systematic studies of flow regimes, aeration processes, and energy dissipation mechanisms. Advances in computational fluid dynamics (CFD) have further expanded this research, enabling detailed simulations of complex hydraulic interactions that were once described only qualitatively.
cost-effective alternative to conventional manufacturing techniques for applications requiring components with complex geometries. Cost savings are achieved through reduced raw material usage, shorter manufacturing times, and the elimination of expensive tooling. AM serves as a valuable tool for designing and developing complex shapes in fluid flow research. Stepped spillways are widely recognized for their effectiveness in dissipating energy and are implemented globally. Their optimal design is critical for reducing downstream erosion and improving the economic efficiency of stilling basin configurations. Building on previous studies employing AM in open-channel flow applications, this paper presents a comparative analysis of two stepped spillway configurations incorporating preceding weir designs. The comparison evaluates fluid velocity profiles, discharge rates, upstream and downstream water depths, associated hydraulic parameters, and experimental observations. To validate and extend the findings, this paper employs computational fluid dynamics (CFD) modelling, which demonstrates strong agreement with experimental results. Additional tests investigate sealed and unsealed models, the latter allowing significant side flow. This paper highlights how AM enables economical small-scale model fabrication, which can enhance largescale design processes and contribute to the advancement of experimental fluid flow research.
Key Words:
Despite these computational developments, physical modelling remains essential for validating predictions and capturing phenomena—such as air–water interactions, turbulence structures, and surface instabilities—that can be challenging to model numerically. Large-scale models, however, pose practical and economic constraints, especially when multiple design variations are to be tested. In this context, AM provides a transformative advantage: small- and medium-scale AM models can be fabricated rapidly, at low cost, and with precise control over complex geometries. This flexibility enables systematic variation of parameters such as step height, slope, and preceding weir configuration, facilitating efficient design screening before committing to largerscale testing.
CFD Analysis, Additive Manufacturing,
Stepped Spillway
While certain hydraulic behaviours, particularly those subject to scale effects, cannot be fully reproduced in small models, CFD serves as a powerful complement, extending the experimental scope and identifying conditions under which flow regime transitions occur. The integration of AM-fabricated models with CFD analysis therefore offers a cost-effective, flexible, and historically informed approach to spillway research, bridging ancient engineering principles with modern hydraulic science.
1. INTRODUCTION Additive manufacturing (AM) offers a contemporary and versatile approach for advancing experimental techniques in traditional fluid mechanics research. Previous studies by the authors [1,2] have demonstrated the advantages of AM-fabricated models in a range of hydraulic applications, including weirs, drum gates, and flow-altering vanes. Building upon this foundation, the present study applies AM to the fabrication of small-scale stepped spillway models for detailed hydraulic analysis.
The existing experiment at the university for undergraduate Mechanical Engineering students uses a 2.5 m long flow channel (Figure 1), enabling various experiments to observe open channel flow behaviour with
The principle of using stepped spillway structures to dissipate the energy of cascading water is deeply rooted in
© 2025, IRJET
|
Impact Factor value: 8.315
|
ISO 9001:2008 Certified Journal
|
Page 287