# Three-Dimensional Experimental and CFD Characterization of the Airflow Pattern in a Cold Room

C Chevarin, Sami Ben Amara, Graciela Alvarez, Pierre-Sylvain Mirade

► To cite this version:

C Chevarin, Sami Ben Amara, Graciela Alvarez, Pierre-Sylvain Mirade. Three-Dimensional Experimental and CFD Characterization of the Airflow Pattern in a Cold Room. International Congress on Engineering and Food, Apr 2008, Viña del Mar, Chile. hal-05063043

HAL Id: hal-05063043

https://hal.inrae.fr/hal-05063043v1

Submitted on 11 May 2025

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<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Three-Dimensional Experimental and CFD Characterization of the Airflow Pattern in a Cold Room

CHEVARIN Cyril<fnref n="1" />, BEN AMARA Sami<fnref n="2" />, ALVAREZ Graciela<fnref n="2" />, MIRADE Pierre-Sylvain<fnref n="1" />

**Context:**

Controlling airflow inside cold rooms determines the process efficiency in terms of food safety and energy consumption, together with the homogeneity of food product cooling and weight losses.

**Aim of this study:**

To develop 3D CFD models in order to accurately predict airflow pattern and heat and water transfers in large cold rooms, with the final objective of identifying areas potentially contaminated by biological particles.

<figure><img src="image_2.png" /></figure>

Air conditioning
system

Geometry of the cold room

<figure><img src="image_3.png" /></figure>

<figure><img src="image_4.png" /></figure>

6 m long, 4.8 m wide and 2.9 m high (84 m³)

<figure><img src="image_5.png" /></figure>

Filling of the room
(3 rows of stacked
food product models)

## Airflow pattern characterisation

Measurement of air velocities using hot-film type anemometers.

CFD modelling of airflow pattern using Fluent 6 and a mega-porous medium formulation coupled to the Darcy-Forchheimer equation.

<figure><img src="image_6.png" /></figure>

Measured air velocity field

<figure><img src="image_7.png" /></figure>

CFD-calculated air velocity field

1 - A heterogeneous airflow inside the cold room // 2 - A close agreement between the measured and calculated air velocities //

3 - An underestimation of the calculated air velocities in areas where strong gradients exist.

## Prediction of particle deposition

10,000 spherical particles emitted

New configuration of the cold room

<figure><img src="image_8.png" /></figure>

New filling of the room:
using 9 big blocks

CFD modelling
using a very refined
mesh (y+=4), a
Lagrangian model,
a RSM turbulence
model and a low-
Reynolds number
model at wall level.

The deposition varies with the particle diameter according to the different physical phenomena involved (inertia, sedimentation, Brownian diffusion, turbulent diffusion, impaction, interception).

Percentage of deposited particles on room surfaces

<figure><img src="image_9.png" /></figure>

## Conclusions:

Possibility, using CFD, of predicting the air velocity, temperature and relative air humidity fields in large rooms, together with the contaminating particle dispersion and deposition.

The numerical approach developed could certainly improve the hygiene in the food industry.

<figure><img src="image_10.png" /></figure>

<footnote n="1">¹ UR370 Qualité des Produits Animaux, INRA, F-63122 St-Genès-Champanelle, France.</footnote>

<footnote n="2">² UR Génie des Procédés Frigorifiques, CEMAGREF, Parc de Tourvoie, BP44, F-92163 Antony, France.</footnote>