View factor radiation parameters

To account for the effects of orientation on radiation heat transfer between two surfaces, we define a new parameter called the vieu factor, which is a purely geometric quantity and is independent of the surface properties and temperature. It is also called the shape factor, configuration factor, and angle factor. The view factor based on the assumption that the surfaces are diffuse emitters and diffuse reflectors is called the diffitse view factor, and the view factor based on the assumption that the surfaces are diffuse emitters but specular reflectors is called the specular view factor. In lliis book, we consider radiation exchange between diffuse surfaces only, and ihu.s the term view factor simply means diffuse view factor. 

Radiaton heal transfer between surfaces depends on the orientation of the surfaces relative to each other. In a radiation. analysis, this effect is accounted for by the geometric parameter vie.iv facior. The vretv factor ftoni a surface i to a. surface j is denoted by or F j, and is defined as the fraction of the radiation leaving surface i that strikes surface j directly. The view factors between differential and finite surfaces are expressed as... 

Approximate Geometric, Layered Model. Using geometric optics (radiation size parameter OCr, larger than about five) and the concept of view factor, the emission, transmission, and reflection of periodically arranged, diffuse, opaque particles has been modeled by Mazza et... 

Other Types of Fires. For the other types of fires, avaUable models are broadly classified as eifher poinf-source models (simple or with multiple sources) or view-factor models based on either an equivalent radiator or a solid flame approach. They differ in their required input parameters according to the type of fire and the level of detail and complexity inherent in the inputs and submodels needed to describe the physical event. 

Figure 7.9. The observed (Mo Ka radiation) and calculated powder diffraction patterns of LaNi4 85Sno.i5 after combined refinement of scale factors only. The inset shows the expanded view between 18.4 and 19.5° of 20 to illustrate the inaccuracy of lattice parameters.

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