Wall condition

There have also been reports of adding zinc chloride or tin chloride to the Morgan-Walls conditions to catalyze the reaction (see experimental section). ... 

Figure 10-28. Tube wall conditions affecting overall heat transfer and associated temperature profile.

No slip Is used as the velocity boundary conditions at all walls. Actually there Is a finite normal velocity at the deposition surface, but It Is Insignificant In the case of dilute reactants. The Inlet flow Is assumed to be Polseullle flow while zero stresses are specified at the reactor exit. The boundary conditions for the temperature play a central role in CVD reactor behavior. Here we employ Idealized boundary conditions In the absence of detailed heat transfer modelling of an actual reactor. Two wall conditions will be considered (1) adiabatic side walls, l.e. dT/dn = 0, and (11) fixed side wall temperatures corresponding to cooled reactor walls. For the reactive species, no net normal flux Is specified on nonreacting surfaces. At substrate surface, the flux of the Tth species equals the rate of reaction of 1 In n surface reactions, l.e. 

Therefore the behaviour of a power law fluid, evaluated at the wall conditions, is given by... 

A basic requirement for electrochemical pore formation is passivation of the pore walls and passivity breakdown at the pore tips. Any model of the pore formation process in silicon electrodes has to explain this difference between pore tip and pore wall conditions. Three different mechanisms have been proposed to explain the remarkable stability of the silicon pore walls against dissolution in HF, as shown in Fig. 6.1. 

The side wall conditions (6.4.51)-(6.4.53) are replaced by the symmetry conditions... 

The primary photodissociation yield is unity at 1849 A (measured by the yield of 0(3P) atom production), although the quantum yields of CO and 02 are much less than 1 and 0.5 respectively [DeMore and Mosesman (278)]. The quantum yield of CO is 0.2 to 1, depending on wall conditions (278). The 02 to CO ratio is 0 to 0.4, which is less than the 0.5 expected from (VI-16) followed by the combination of O atoms... 

The products of the photolysis of C02 are CO, 02, and small amounts of 03 at all incident wavelengths. However, the quantum yield of CO is not always unity. Furthermore, the ratio 02/CO is usually less than half that expected from material balance. It appears that wall conditions arc an... 

For the next generation of D-T tokamaks (JET and TFTR), titanium gettering cannot be used as a wall conditioning or a... 

Table I. Asymptotic dimensionless laminar flow heat or mass transfer coefficients Nu = a dh/V, (constant wall conditions) and Fanning friction factor / for pressure drop Ap = 2f r 7.ijd ) g for ducts of different cross section [10).

Then, integrating Eq. (5-109) between wall conditions and mean bulk conditions gives... 

Under the conditions indicated in the table, IB-100 and 1C-100 show the results of the explosion of a lOOg explosive package in a single container filled with sand as measured at the receiving room above and to the side of the container in the absence of a sand wall. Condition 2B-100 has no a sand wall. Conditions IB Dry-100 and IB Wet-100 are filled with dried sand and sand saturated with water respectively. 

Note that the solutions depend on Re3molds number, that is implicitly included in the Y or rj co-ordinate itself. The numerical results of these were presented in Schneider (1979) and an interesting feature of it was seen that the wall slope for 0 is equal to zero for all values of K-, implying the solution to be given for adiabatic wall condition. 

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