[mehtab]

Hi Foamers,

I am using fireFoam solver for simulating turbulent diffusion flames. Is the pyrolysis model present in fireFoam solver capable fo modelling liquid evaporation as well.

I referred technical reference guide of FDS(Fire Dynamics Simulator) and it is mentioned there that FDS can model evaporation of liquid fuel to calculate burned mass of fuel.
http://eamcweb4.usfs.msu.edu/study20...ence_Guide.pdf (section- 7.2.4)

Is this model also available in OpenFoam?

Thanks

[atulkjoy]

Hi Sir,
I know its quite to reply,


FireFoam models pyrolysis can be used to evaporation due to there is no limiting temperature of evaporation in liquid maimim temperature can be boiling point but at solid interface either charring or non charring fuel , temperature will increase.

Secong FDS fuel boundary condition is not an good option either because the interface boundary has been derived by sharwood number and reynold number assumption for convective length scale.


you can use just use FDS formulation up to clausis cleyparon equation than couple it with diffusion velocity V = rhos*vs*Hfg on liquid interface and surface heat transfer kdT/dx = rhos*Vs*Hfg

where dT/dx is sngrad for temperature at interface
rhos is density of vapour at interface, Vs is diffusion velocity, Hfg is latent heat and k is conductivity of mixture at interface


It is similar so stefan flow problem or refer jounal of K. prasad et al
Numerical modelling of methanol liquid pool fires

[charles4allme]

Originally Posted by atulkjoy

Hi Sir,
I know its quite to reply,


FireFoam models pyrolysis can be used to evaporation due to there is no limiting temperature of evaporation in liquid maimim temperature can be boiling point but at solid interface either charring or non charring fuel , temperature will increase.

Secong FDS fuel boundary condition is not an good option either because the interface boundary has been derived by sharwood number and reynold number assumption for convective length scale.


you can use just use FDS formulation up to clausis cleyparon equation than couple it with diffusion velocity V = rhos*vs*Hfg on liquid interface and surface heat transfer kdT/dx = rhos*Vs*Hfg

where dT/dx is sngrad for temperature at interface
rhos is density of vapour at interface, Vs is diffusion velocity, Hfg is latent heat and k is conductivity of mixture at interface


It is similar so stefan flow problem or refer jounal of K. prasad et al
Numerical modelling of methanol liquid pool fires

Hi atulkjoy,

Do you have any code relating to the above method. I am currently looking into this problem

[Zhiheng Wang]

f you consider the flame occupied whole pool surface, fuel feed rate from pool to flame becomes steady. the you can take interface boundary conditions where Ts=0.98TbNow you need iterartions because inlet velocity will depend up on



Temperature of surface and Yf( mss fraction of fuel at surface).
Velocity at interface = (Yf/Yf-1)*(dYf/dn) and claussious cleparon equation
SO you can see due to temperature and Yf are coupled you need to solve them in a loop with converged Ts and Yf.