Research Article
Optimization of Airflow Profiles and Thermal Uniformity in a Cold Room at Negative Temperature
Abena Gabriel Brice*
,
Kewou Serge,
Gnepie Takam Nicolas Wilfried,
Tientcheu Nsiewe Maxwell,
Kuitche Alexis
Issue:
Volume 11, Issue 2, June 2026
Pages:
39-55
Received:
2 April 2026
Accepted:
11 April 2026
Published:
25 April 2026
Abstract: This study presents a CFD-based optimization of airflow and thermal uniformity in a negative-temperature cold storage room (6.8 × 2.4 × 3 m), simulated using ANSYS 19.4 with the Realizable k-ε turbulence model. Four pallet loading configurations were evaluated on a computational mesh of 470,780 elements, with convergence residuals ≤ 10-5. Boundary conditions included a supply air temperature of 248.15 K (−25°C), an inlet velocity of 4 m/s, and an ambient external temperature of 303.15 K (30°C). Baseline simulations showed pallet surface temperatures ranging from 250.4 K to 256.4 K, resulting in a maximum thermal non-uniformity of ΔT = 6 K. Stagnant zones exhibited velocities below 0.5 m/s, with longitudinal velocity dropping to 0.2 m/s at z = 6 m. In Case 2, a thermal gradient of approximately 6 K was observed between the top and center of the storage zone. Peak temperatures reached 257.3 K in low-velocity regions, where airflow between pallets fell below 0.25 m/s. In Case 3, jet velocities reached up to 10 m/s at the evaporator outlet but decayed to below 1 m/s upon entering the storage zone. Product temperatures subsequently rose to 264 K at z > 4 m. The optimized configuration (Case 4) featured a stepped pallet arrangement with 0.1 m inter-pallet spacing and an increased supply velocity of 12.4 m/s. This reduced the maximum temperature difference to ΔT = 2.4 K (249.3 K – 251.7 K), representing a 60% improvement in thermal homogeneity. Longitudinal velocity at the chamber bottom improved from 0.2 m/s to 1.2 m/s (+500%), and vertical thermal stratification decreased from 5.6 K to 2.0 K (−64%). Critically, iso-clip analysis confirmed that hot zones exceeding 255 K were virtually eliminated in the optimized case.
Abstract: This study presents a CFD-based optimization of airflow and thermal uniformity in a negative-temperature cold storage room (6.8 × 2.4 × 3 m), simulated using ANSYS 19.4 with the Realizable k-ε turbulence model. Four pallet loading configurations were evaluated on a computational mesh of 470,780 elements, with convergence residuals ≤ 10-5. Boundary ...
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Research Article
Evaluation of Glycemic Index, Antinutritional and Sensory Properties of Fufu from Blends of Aerial Yam (AYF), Finger Millet (FMF) and Pro-Vitamin A Cassava Flours (PVACF)
Nwabueze Joseph Mbam*,
Francis Chiwendu Ekwu,
Odo Micheal Odo,
Gloria Ijeoma Gibson-Umeh,
Ogah Anselem Ogah,
Ugwu Ifeoma Mary
Issue:
Volume 11, Issue 2, June 2026
Pages:
56-66
Received:
17 March 2026
Accepted:
28 March 2026
Published:
29 April 2026
DOI:
10.11648/j.ajset.20261102.12
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Abstract: The study x-rays the evaluation of glycemic index, Antinutritional and sensory properties of fufu blends of Aerial yam (Dioscorea bulbifera), finger millet (Eleusine coracana) and pro vitamin A cassava (Manihot esculanta “Yellow cassava”). The experiments were conducted using the simplex centroid design, 14 formulations were obtained using mixture response surface methodology as the optimizing technique. The formulated flour blends showed that there was significant difference (P<0.05) between the range of values 51.77-56.03 for Glycemic index and 14.14 -21.08 Glycemic load respectively. The anti-nutrients showed tannin, phytate, oxalate and total phenolic contents of 0.35-3.39, 1.07- 6.57, 0.84 - 3.43, and 0.59- 1.91mg/100g respectively. Significant differences did not exist (P>0.05) amongst the observed values for tannin, phytate, oxalate and phenol content. Results of the fufu blends revealed sensory score of the flour blends fufu for appearance, taste, mould ability, stickiness, consistency, colour and overall acceptability were 4.69-7.34; 4.02-5.57; 5.79-8.21; 3.80-7.71; 5.84-8.53; 2.33-7.13; and 6.33-8.20 respectively. The study showed that flour blends from aerial yam flour (AYF), finger millet flour (FMF) and pro vitamin A cassava flour (PVACF) have great potentials in the production of fufu with wide range of nutritional and sensory attributes, therefore can be used as nutritious and convenient functional foods. Enabling a new product (starch flour) source for the development of food products that can reduce dependence on other starch sources such as corn and rice.
Abstract: The study x-rays the evaluation of glycemic index, Antinutritional and sensory properties of fufu blends of Aerial yam (Dioscorea bulbifera), finger millet (Eleusine coracana) and pro vitamin A cassava (Manihot esculanta “Yellow cassava”). The experiments were conducted using the simplex centroid design, 14 formulations were obtained using mixture ...
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