Analysis of components effecting free convection intensity in steel rectangular sections

• Autorzy: Wyczółkowski R.

Identyfikatory

DOI

10.1515/aoter-2015-0024

• Języki publikacji: EN

Abstrakty

EN

Free convection is one of the heat transfer modes which occurs within the heat-treated bundles of steel rectangular section. A comprehensive study of this phenomenon is necessary for optimizing the heating process of this type of charge. The free convection intensity is represented by the Rayleigh number Ra. The value of this criterion depends on the following parameters: the mean section temperature, temperature difference within the section, kinematic coefficient of viscosity, volume expansion coefficient and the Prandtl number. The paper presents the analysis of the impact of these factors on free convection in steel rectangular sections. The starting point for this analysis were the results of experimental examinations. It was found that the highest intensity of this process occurs for the temperature of 100°C. This is mainly caused by changes in the temperature difference observed in the area of sections and changes in kinematic coefficient of viscosity of air. The increase in the value of the Rayleigh number criterion at the initial stage is attributable to changes in the parameter of temperature difference within the section. After exceeding 100°C, the main effect on convection is from changes in air viscosity. Thus, with further increase in temperature, the Rayleigh number starts to decline rapidly despite further rise in the difference in temperature.

Słowa kluczowe

EN

free convection; Rayleigh number; section bundles; effective thermal conductivity; heat treatment

PL

konwekcja swobodna; liczbia Rayleigha; przewodność cieplna efektywna; obróbka cieplna

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2015
• Tom: Vol. 36, no. 3
• Strony: 105--121
• Opis fizyczny: Bibliogr. 16 poz., rys., tab.

Twórcy

autor

Wyczółkowski R.

• Czestochowa University of Technology, Faculty of Production Engineering and Materials Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

Bibliografia

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