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Flow uniformity inside the drying chamber of a heat exchanger-based solar dryer : numerical analysis with smoke flow visualization as experimental validation

Adhikari, Navaraj ; Garg, Himani LU orcid ; Davidsson, Henrik LU ; Baral, Bivek and Andersson, Martin LU orcid (2025) In Results in Engineering 26.
Abstract

Solar drying technologies have emerged as efficient and user-friendly solutions for food drying processes, particularly in regions with limited access to electricity and high post-harvest losses. These technologies offer a sustainable alternative to conventional drying methods. However, one of the key challenges limiting their effectiveness is the non-homogeneous airflow inside the drying chamber, which can lead to non-uniform drying, extending drying time, and potential degradation in product quality. This research addresses the problem of airflow non-uniformity by optimizing the internal flow distribution inside the drying chamber. Numerical models using ANSYS Fluent, based on the finite volume method, were employed to analyze the... (More)

Solar drying technologies have emerged as efficient and user-friendly solutions for food drying processes, particularly in regions with limited access to electricity and high post-harvest losses. These technologies offer a sustainable alternative to conventional drying methods. However, one of the key challenges limiting their effectiveness is the non-homogeneous airflow inside the drying chamber, which can lead to non-uniform drying, extending drying time, and potential degradation in product quality. This research addresses the problem of airflow non-uniformity by optimizing the internal flow distribution inside the drying chamber. Numerical models using ANSYS Fluent, based on the finite volume method, were employed to analyze the airflow behaviors under different design configurations. To validate the numerical model, smoke flow visualization experiments were conducted in two configurations: with and without trays in the drying chamber. Six design configurations were examined by altering parameters such as inlet size and internal flow arrangement. Airflow uniformity was evaluated using parameters such as uniformity index and coefficient of variation, measured along multiple lines across the drying chamber. The results indicated that our optimized model has a higher uniformity index and lower coefficient of variation than the base model of the drying chamber, leading to a more uniform airflow distribution. These improvements contribute to more consistent drying conditions, reduced drying time, and enhanced system efficiency. These findings highlight the potential of strategic design adjustments for the drying chamber to improve drying performance, making solar dryers more effective and reliable.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Drying chamber, Flow uniformity, Numerical simulation, Smoke flow experiment, Solar dryer
in
Results in Engineering
volume
26
article number
105553
pages
16 pages
publisher
Elsevier
external identifiers
  • scopus:105007843894
ISSN
2590-1230
DOI
10.1016/j.rineng.2025.105553
language
English
LU publication?
yes
id
bd452314-f549-41d7-ab97-b68d90219002
date added to LUP
2025-06-19 17:29:11
date last changed
2025-07-31 18:14:09
@article{bd452314-f549-41d7-ab97-b68d90219002,
  abstract     = {{<p>Solar drying technologies have emerged as efficient and user-friendly solutions for food drying processes, particularly in regions with limited access to electricity and high post-harvest losses. These technologies offer a sustainable alternative to conventional drying methods. However, one of the key challenges limiting their effectiveness is the non-homogeneous airflow inside the drying chamber, which can lead to non-uniform drying, extending drying time, and potential degradation in product quality. This research addresses the problem of airflow non-uniformity by optimizing the internal flow distribution inside the drying chamber. Numerical models using ANSYS Fluent, based on the finite volume method, were employed to analyze the airflow behaviors under different design configurations. To validate the numerical model, smoke flow visualization experiments were conducted in two configurations: with and without trays in the drying chamber. Six design configurations were examined by altering parameters such as inlet size and internal flow arrangement. Airflow uniformity was evaluated using parameters such as uniformity index and coefficient of variation, measured along multiple lines across the drying chamber. The results indicated that our optimized model has a higher uniformity index and lower coefficient of variation than the base model of the drying chamber, leading to a more uniform airflow distribution. These improvements contribute to more consistent drying conditions, reduced drying time, and enhanced system efficiency. These findings highlight the potential of strategic design adjustments for the drying chamber to improve drying performance, making solar dryers more effective and reliable.</p>}},
  author       = {{Adhikari, Navaraj and Garg, Himani and Davidsson, Henrik and Baral, Bivek and Andersson, Martin}},
  issn         = {{2590-1230}},
  keywords     = {{Drying chamber; Flow uniformity; Numerical simulation; Smoke flow experiment; Solar dryer}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Results in Engineering}},
  title        = {{Flow uniformity inside the drying chamber of a heat exchanger-based solar dryer : numerical analysis with smoke flow visualization as experimental validation}},
  url          = {{http://dx.doi.org/10.1016/j.rineng.2025.105553}},
  doi          = {{10.1016/j.rineng.2025.105553}},
  volume       = {{26}},
  year         = {{2025}},
}