Original title: Součinitele prostupu tepla při obtékání měděné koule se speciální izolační vrstvou
Translated title: Effect of Aero-Therm insulation layer on the overall heat transfer coefficient
Authors: Kordík, Jozef
Document type: Research reports
Year: 2019
Language: cze
Series: Z-1602/19
Abstract: [cze] [eng]
Cílem této výzkumné zprávy je stanovení součinitelů prostupu tepla pro vybrané případy obtékaní měděné koule. Měděná koule byla zkoumána ve třech variantách, které se lišily povrchovou úpravou. V první variantě se jednalo o kouli o průměru 40mm bez povrchové úpravy, na povrchu koule byla tedy pouze vrstva oxidu mědi. Další variantu představovala koule s nanesenu izolační vrstvou Aero-Thermo o tloušťce cca 1.6mm. Poslední, třetí varianta se od druhé lišila v tloušťce izolační vrstvy, která v tomto případě byla 2.9mm. Součinitele prostupu tepla byly stanoveny pro případy ochlazování koule pomocí nucené konvekce. The aim of this work was to test the properties of Aero-Therm insulation layer by determining overall heat transfer coefficients for selected cases of flow past a sphere. The material of the sphere was copper to minimize uncertainties due to internal temperature gradients. Three variants were examined, which differed in sphere surface thermal insulation. In the first variant, the sphere with a diameter of 40 mm had no insulation; only a thin layer of a copper oxide was present on the surface only. In the second variant, the sphere was coated with Aero-Therm insulating layer with a thickness of about 1.5 mm. The third variant differed from the second one in the thickness of the insulating layer, which was 2.9 mm in this case. The overall heat transfer coefficients were determined for cooling the sphere by a forced convection by air at various flow velocities.
Keywords: heat transfer coefficient; nusselt number; overall heat transfer coefficient

Institution: Institute of Thermomechanics AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0304215

Permalink: http://www.nusl.cz/ntk/nusl-408927


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