International Journal of Engineering

International Journal of Engineering

A Comparative Study of Laminar and Turbulent Flow in Ribbed Wavy Channels: Effects of Rib Height, Angle, and Density

Document Type : Original Article

Authors
A. H. Ghalta 1, 2
M. Farhadi 2
1 Department of Refrigeration and Air Conditioning Engineering Technologies, College of Engineering Technologies, University of Hilla, Hilla, Iraq
2 Faculty of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, I. R. of Iran
10.5829/ije.2026.39.10a.13
Abstract
This study investigates the thermal–hydraulic performance of wavy channels equipped with transverse ribs, addressing the need for optimized heat transfer solutions in compact heat exchangers, where the combined effects of rib geometry and flow regime remain insufficiently explored. The objective is to evaluate how rib inclination angle, height, and count influence heat transfer enhancement and overall efficiency under both laminar (Re = 500) and turbulent (Re = 5000) flow conditions. Three-dimensional numerical simulations were performed using ANSYS Fluent to analyze heat transfer characteristics, frictional losses, and the performance evaluation criterion (PEC). The results show that transverse ribs significantly enhance heat transfer by promoting flow separation and vortex formation. In laminar flow, Nusselt numbers increased by up to ~50% compared to smooth channels, with optimal PEC values achieved at moderate rib heights (h/H = 0.2–0.4), rib angles of 45°–60°, and low rib counts (N = 1–2). In turbulent flow, heat transfer enhancement was more pronounced (Nusselt numbers ~56–58), although increased friction led to PEC values below unity in most cases. Novel trade-offs were identified that balance thermal performance and efficiency, especially in laminar regimes. These findings contribute valuable design guidelines for the geometric optimization of ribbed wavy channels in different flow regimes.

Graphical Abstract

A Comparative Study of Laminar and Turbulent Flow in Ribbed Wavy Channels: Effects of Rib Height, Angle, and Density
Keywords
Wavy Channel
Ribbed Surfaces
Heat Transfer Enhancement
Erformance Evaluation Criterion (PEC)

Subjects

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International Journal of Engineering
Volume 39, Issue 10
TRANSACTIONS A: Basics
October 2026
Pages 2509-2520