Influence of surface roughness topography on heat transfer in turbulent flows
Garg, Himani LU
; Nogenmyr, Karl-Johan
and Stroh, Alexander
(2026)
- Abstract
- This study models Additive Manufacturing (AM) roughness using a statistical distribution of spheres and performs high-fidelity simulations at a bulk Reynolds number of 12,000 and a large range of Prandtl numbers to evaluate heat transfer on a rough pipe. Statistical measures were deployed to highlight a clear correlation between roughness features and heat transfer. To directly connect surface topography with local heat transfer, the roughness height map was classified into quantile-based roughness zones: canyons, lower slopes, up per slopes, and tips. Probability density functions of the normalized Nusselt number in these zones reveal a clear stratification of convective performance: canyon regions exhibit the lowest heat transfer due to... (More)
- This study models Additive Manufacturing (AM) roughness using a statistical distribution of spheres and performs high-fidelity simulations at a bulk Reynolds number of 12,000 and a large range of Prandtl numbers to evaluate heat transfer on a rough pipe. Statistical measures were deployed to highlight a clear correlation between roughness features and heat transfer. To directly connect surface topography with local heat transfer, the roughness height map was classified into quantile-based roughness zones: canyons, lower slopes, up per slopes, and tips. Probability density functions of the normalized Nusselt number in these zones reveal a clear stratification of convective performance: canyon regions exhibit the lowest heat transfer due to shielding and limited turbulent renewal, while tip regions consistently achieve the highest values through direct exposure to turbulent eddies and boundary-layer disruption. A complementary sheltering analysis based solely on surface visibility to the incoming flow distinguishes weakly ventilated regions with suppressed heat transfer from exposed windward faces that host intense thermal events. Probability density functions of the local Nusselt number based on sheltering analysis reveal pronounced spatial variability linked to surface geometry. These findings highlight the central role of roughness elevation and spatial exposure in governing turbulent heat transfer and provide new insights into the thermal–hydrodynamic behavior of AM-fabricated channels. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/b18b024f-8b92-48f2-bb45-6e8a7265d23d
- author
- Garg, Himani
LU
; Nogenmyr, Karl-Johan
and Stroh, Alexander
- organization
- publishing date
- 2026
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- Proceedings of the 14th International Symposium on Turbulence and Shear Flow Phenomena (TSFP14)
- pages
- 5 pages
- language
- English
- LU publication?
- yes
- id
- b18b024f-8b92-48f2-bb45-6e8a7265d23d
- alternative location
- http://www.tsfp-conference.org/proceedings/2026/277.pdf
- date added to LUP
- 2026-09-10 06:36:33
- date last changed
- 2026-09-16 13:04:36
@inproceedings{b18b024f-8b92-48f2-bb45-6e8a7265d23d,
abstract = {{This study models Additive Manufacturing (AM) roughness using a statistical distribution of spheres and performs high-fidelity simulations at a bulk Reynolds number of 12,000 and a large range of Prandtl numbers to evaluate heat transfer on a rough pipe. Statistical measures were deployed to highlight a clear correlation between roughness features and heat transfer. To directly connect surface topography with local heat transfer, the roughness height map was classified into quantile-based roughness zones: canyons, lower slopes, up per slopes, and tips. Probability density functions of the normalized Nusselt number in these zones reveal a clear stratification of convective performance: canyon regions exhibit the lowest heat transfer due to shielding and limited turbulent renewal, while tip regions consistently achieve the highest values through direct exposure to turbulent eddies and boundary-layer disruption. A complementary sheltering analysis based solely on surface visibility to the incoming flow distinguishes weakly ventilated regions with suppressed heat transfer from exposed windward faces that host intense thermal events. Probability density functions of the local Nusselt number based on sheltering analysis reveal pronounced spatial variability linked to surface geometry. These findings highlight the central role of roughness elevation and spatial exposure in governing turbulent heat transfer and provide new insights into the thermal–hydrodynamic behavior of AM-fabricated channels.}},
author = {{Garg, Himani and Nogenmyr, Karl-Johan and Stroh, Alexander}},
booktitle = {{Proceedings of the 14th International Symposium on Turbulence and Shear Flow Phenomena (TSFP14)}},
language = {{eng}},
title = {{Influence of surface roughness topography on heat transfer in turbulent flows}},
url = {{http://www.tsfp-conference.org/proceedings/2026/277.pdf}},
year = {{2026}},
}