Internal energy convective flux

In the cooling or heating of a vessel which contains a fluid, the temperature 41 of this fluid can often be taken as spatially constant, as the temperatures in each individual part of the fluid will be equalized either by convection or mixing. The change in the temperature 41 = p (t) over time depends on the manner in which heat is transferred from the vessel wall (the conductive body) to the fluid. This causes a change in the internal energy of the fluid and a corresponding variation in dp. The heat flux is then... 

The contribution from bulk fluid flow via the convective flux of kinetic and internal energies, which is contained in the first term on the right side of (25-32)... 

The air temperature of a room at any given time is given hy a heat-balance equation which includes the heat flux exchanged by convection at each wall element (A q ), the heat flow exchanged by ventilation (4>j,), the convective part of heat flow due to internal heat gains the convective part of heat flow due to the HVAC system (< >[,(.), and the variation of energy in the room air(r M ... 

Figure 4 Normalised mass G(a), energy H(a), average enthalpy increase K(a) and transition mass flux g(a) of a droplet for the cases of (a) enthalpy improved 3EM and (b) for standard 3EM. Ambient temperature dFiame = 900°C, initial temperature 910 = 270°C, transition temperature STrans = 420 °C, initial droplet diameter di,0= 400mm, Nusselt number 18 and amplification factor of the heat conduction coefficient due to internal forced convection IWkmoiec = 2.72 (Beer [5]), residence time t=30 ms.

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