Tools › Fluids and Heat Transfer › Radiation

Radiation

1 tool in the Fluids and Heat Transfer area.

Radiation View Factors

View factors between surfaces from the closed forms of Hamilton and Morgan (NACA TN 2836): aligned parallel rectangles, perpendicular rectangles sharing an edge, coaxial discs, concentric cylinders of finite length, a differential element facing a rectangle (parallel or at an angle) or an offset disc, and the limiting cases of infinite parallel plates, long concentric cylinders, concentric spheres and a sphere over a plane. The factor is written out with the substituted values and checked by reciprocity and summation. The grey-body radiosity network of the two surfaces and their surroundings (re-radiating, or at a set temperature) is assembled with the surface resistances (1 − ε)/(εA) and space resistances 1/(AF), solved and printed as a matrix, giving the radiosities and the net heat rate of every surface; radiation shields reduce the exchange of the infinite-plate, long-cylinder and sphere geometries. The default case is two aligned 1 × 2 m rectangles 1 m apart at 500 K and 300 K with emissivities 0.8 and 0.5 (F12 = 0.2859, Table 12 of the report).

1 worked example reproduced, listed on the tool page.

Other Fluids and Heat Transfer sections

Pipe Flow · Pumps and Fans · Compressible Flow · Conduction · Convection · Heat Exchangers · Thermodynamic Cycles · Fluid Properties