WASET
	%0 Journal Article
	%A Jaehyug Lee and  Tae-Ho Song
	%D 2015
	%J International Journal of Energy and Power Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 97, 2015
	%T Analysis of Combined Heat Transfer through the Core Materials of VIPs with Various Scattering Properties
	%U https://publications.waset.org/pdf/10000076
	%V 97
	%X Vacuum Insulation Panel (VIP) can achieve very low
thermal conductivity by evacuating its inner space. Heat transfer in the
core materials of highly-evacuated VIP occurs by conduction through
the solid structure and radiation through the pore. The effect of various
scattering modes in combined conduction-radiation in VIP is
investigated through numerical analysis. The discrete ordinates
interpolation method (DOIM) incorporated with the commercial code
FLUENT® is employed. It is found that backward scattering is more
effective in reducing the total heat transfer while isotropic scattering is
almost identical with pure absorbing/emitting case of the same optical
thickness. For a purely scattering medium, the results agrees well with
additive solution with diffusion approximation, while a modified term
is added in the effect of optical thickness to backward scattering is
employed. For other scattering phase functions, it is also confirmed
that backwardly scattering phase function gives a lower effective
thermal conductivity. Thus the materials with backward scattering
properties, with radiation shields are desirable to lower the thermal
conductivity of VIPs.

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