Thermal Radiation in Laminar Boundary Layers on Continuous Moving Surfaces

1974 ◽  
Vol 96 (1) ◽  
pp. 32-36 ◽  
Author(s):  
C. A. Rhodes ◽  
C. C. Chen

Thermal radiation heat transfer is studied in boundary layers on continuous moving surfaces. An analytical study is performed for two-dimensional laminar flow of an absorbing and emitting fluid. Solutions were obtained for limiting conditions of optically thin and thick boundary layers. Comparisons indicate that the radiation flux in these boundary layers is less than that for flow over semi-infinite flat plates for optically thin flows. The radiation contribution becomes more nearly equal as optical thickness increases. The normal velocity induced in the free stream by the wall motion significantly affects the radiation heat transfer.

Author(s):  
Shigeki Hirasawa ◽  
Hiroyuki Ishibashi ◽  
Kazuhisa Kurashige ◽  
Akihiro Gunji

Temperature distributions and thermal stress distributions in a semi-transparent GSO crystal during Czochralski (CZ) single crystal growth were numerically investigated by thermal radiation heat transfer analysis and anisotropy stress analysis. As GSO has special optical properties, such as semi-transparency at a wavelength shorter than 4.5 μm, thermal radiation heat transfer was calculated by the Monte Carlo method. These calculations showed that thermal stress is caused by the radial temperature distribution on the outside of the upper part of the crystal. To reduce this temperature distribution, the following three manufacturing conditions were found to be effective: use a sharp taper angle of the crystal, install a lid to the top of the insulator, and install a ring around the tapered part of the crystal.


Sign in / Sign up

Export Citation Format

Share Document