Axial radiation flux

For the region near the attachment point, Mullis found a strong effect of axial position on flux, but no satisfactory general correlation for this effect. In addition, he found no quantitative relation for the heat-transfer characteristics of jets directed toward the propellant surface. Under most conditions studied by Mullis, the radiation contribution is approximately 10% of the convective flux. The effects of solid-particle impingement were not investigated. 

Bech Nielsen et a/. s experimental channeling data for the (100) axial channels is shown in Fig. 14. Together with 111 planar data, which showed a pronounced flux peak, these data clearly indicate a near bond-center site for the 2H. According to Bech Nielsen s analysis, the best fit to the data was obtained with 87% of the 2H atoms in the sample assigned to near BC sites and the rest to T sites. However, the attribution of the minority component could be influenced by radiation effects during the analysis, as will be discussed later. 

Radiative boundary condition, denoted by . This boundary condition involves radiative heat transfer from the duct to the environment. The wall heat flux is proportional to the fourth power of the absolute wall temperature, and the environment temperature is uniform in the axial direction. This boundary condition can be found in high-temperature systems such as space radiators, liquid-metal exchangers, and heat exchangers involving heat-radiating gases. 

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