Learning Forum

[z5489721]

In my dpm model i use multicomponent type for particles. I want to calculate the particle temperature using the full energy balance equation within a UDF in Fluent. Which macro should I use for this purpose? If radiation is enabled in Fluent, does it automatically account for radiative heat transfer, or do I need to manually include both convective and radiative terms in the UDF? m_p * c_p,p * dT_p/dt = h * A_p * (T_g - T_p) + A_p * ε_p * σ * (θ_R^4 - T_p^4) + f_h * (dm_p/dt) * H_reaction

[Rob]

Fluent should do all of that for you - ie particle temperature is calculated in the solver. What are you trying to do?

[z5489721]

I am modelling reduction of hematite and my particle type is multicomponent. When you select multicomponent particle, heat of reaction is not calculated. So How can i show effect of heat from reduction in the system? I was thinking to use DEFINE_DPM_HEAT_MASS macro to consider gas phase enthalpy and particle temperature change.  but I am not sure. If it is right way, do i need to consider radiation and convection terms in the equation too or just heat of reaction part?

[Ren]

Hello,

The multicomponent particles are for droplets. If the particles you are modelling are solid combusting (reacting) particles, you need to define them as the combusting particles. In both cases, you need to activate the particle reaction option in the Species Model dialog box and define the appropriate particle reactions. After this is done, the heat of reaction due to particle reactions will automatically be included by Fluent.

Particle radiation interaction is not included by default. It needs to be activated in the DPM dialog box.

If you use any UDF to calculate the particle heat transfer, you need to take care of everything in the UDF.