Characterization of 3D Surface Roughness and Drag Reduction (CFD)

CFD-based investigation of turbulent flow over smooth and rough channels, focusing on the effect of 3D surface roughness on drag and heat transfer. The study replicates and validates results from the literature using RANS models and benchmarks velocity, temperature, and Nusselt number profiles.

Project Overview

• Characterized 2D and 3D surface roughness parameters (Ra, Rq, Sk, Ku, Spd, Vmc)
• Designed multiple rough channel geometries (circular, rectangular, triangular, cratered)
• Validated CFD predictions against literature for turbulent channel flow
• Investigated drag increase and negative velocity shift due to roughness

CFD Details

• Solver: ANSYS Fluent
• Turbulence model: SST k-ω
• Meshing: Mosaic mesh with near-wall refinement (y⁺ < 1)
• Flow condition: Reτ = 500
• Heat flux applied at wall: 400 kW/m²

Key Results

• Roughness induces a clear negative velocity shift in mean velocity profiles
• SST k-ω captures near-wall behavior reasonably well for smooth channels
• Increased skin friction and altered Nusselt number trends observed for rough channels

Repo Structure

• docs/ – project report and references
• geometry/ – rough surface designs
• cfd/ – mesh
• results/ – plots

Skills

CFD • Turbulence Modeling • RANS • SST k-ω • Surface Roughness • Heat Transfer