Page 172 - Industrial Ventilation Design Guidebook
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I 34 CHAPTER 4 PHYSICAL FUNDAMENTALS
Dividing Eq. (4.277) by M A and using Eq. (4.278) gives
because C A = (p A/M A).
In a similar manner, the energy balance equation can be determined:
\ w-'V \j y \j A^ / * £*•
where a = A/pc p and Q is the heat generation per unit volume due to the
chemical reactions (W nrf ), or Q= r^AH, where AH is the reaction heat
(J/rnol). The thermal conductivity of the mixture is A (W m~ K~ ), and c p is
1 1
the specific heat (J kg" KT ), or pc p = p Ac pA + p Bc pB.
Equations (4.279) and (4.280) are similar. Figure 4.37 shows a two-
dimensional boundary layer flow over a plane. Ignoring any chemical re-
actions and considering steady-state conditions, Eqs. (4.279) and (4.280)
give
Assuming laminar flow for a linear momentum equation in the x direction (an
approximation from the Navier-Stokes equations) gives
where v is the kinematic viscosity (m~7s).
Equations (4.281)-(4.283) have to be solved at the same time as the
continuity equation (4.278). The following dimensionless variables are
used:
