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Convection

1 tool in the Fluids and Heat Transfer area.

Convection Correlations

Convective heat-transfer coefficient from the standard correlations, every one that applies to the case shown side by side with its validity range. Nine geometries: internal flow in a tube (fully developed laminar 3.66 and 4.36, Hausen and Sieder–Tate entry-length forms, Dittus–Boelter, Sieder–Tate, Gnielinski and Petukhov with the smooth-tube friction factor), the flat plate (laminar, turbulent and mixed with an entered transition Reynolds number, Churchill–Ozoe for low Prandtl numbers), the cylinder in cross flow (Hilpert, Zukauskas, Churchill–Bernstein), the sphere (Whitaker, Ranz–Marshall), and free convection on vertical and horizontal plates, horizontal cylinders and spheres (Churchill–Chu, McAdams, Morgan, Churchill, with Ostrach's exact laminar solution as the reference). Fluid properties come from the NIST WebBook table for water, from the ideal-gas, Sutherland and Shomate relations for air, or are entered. The tool prints Re, Pr, Gr and Ra, the Nusselt number of each correlation, h = (Nusselt number) k/L, the heat flux and heat rate, and a chart of the Nusselt number against Re or Ra with the case marked. The default is water at 300 K in a 25 mm tube at 1 m/s with the wall at 50 °C: Gnielinski gives a Nusselt number of 192 and h = 4,680 W/(m²·K), Dittus–Boelter 9 % less.

1 worked example reproduced, listed on the tool page.

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