Convective regime classification and heat transfer characterization of domestic electric ovens: effect of enamel coating thickness and cavity geometry on natural convection, thermal resistance, and energy efficiency index
Journal of Thermal Analysis and Calorimetry, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10973-026-16238-0
- Dergi Adı: Journal of Thermal Analysis and Calorimetry
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Chimica, Compendex, Index Islamicus, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Built-in oven, Enamel coating, Enamel thickness, Energy efficiency, Heat transfer
- Erciyes Üniversitesi Adresli: Evet
Özet
This study experimentally investigates the combined effects of enamel coating thickness and shelf geometry on the thermal performance and energy efficiency of domestic electric ovens. Four configurations were tested by varying enamel thickness and shelf design. All four configurations operate in the transition natural convection regime. Dimensionless analysis showed comparable Nusselt numbers between the wire-rack and embossed-rack geometries, indicating that internal convective heat transfer alone does not explain the superior energy class achieved by the embossed-rack configuration. Thermographic and thermocouple measurements instead show that geometric irregularities in the embossed surface promote localized heat accumulation, reducing heat loss to the exterior at the cost of less uniform internal temperature distribution. The enamel layer dominates the composite wall resistance, accounting for up to 93.5% of the total, and doubling its thickness reduces conductive heat flux by 5.0%. The most favorable configuration achieved a 6.3% reduction in energy efficiency index relative to the least efficient design, attaining Energy Class A. These results demonstrate that jointly optimizing enamel thickness, cavity geometry, and surface emissivity is essential for improving oven energy efficiency without modifying the heating system.