look tabel
 

HI, WHile modleing combustion using non-premixed model, fluent generates look tables which can ploted using option Display/pdf curves. In the plot window we have the options called slices and index. can anybody tell me what are they. ??

Thanks in advance

Thanda

Re: look tabel
 

Example: You want to plot the temperature. The temperature in a PDF table is function of the mean mixture fraction, variance of mean mixture fraction and (for non-adiabatic cases) of the heat loss/gain in a cell. As u can see, the temperature is function of 3 variables: to display the temperature values in a 3d graph you have to fix a variable (This is the "costant value of" option). For example you want to fix the mean mf value: you can fix it by chosing a value for it (example f=0.07) or an index (when you have created the PDF table you had to choose the number of dicrete values for the mixture fraction: the default is 31, so you can choose a slice between 1 and 31 so that to this index correspond a mf value). Is it clear now?

Thomas

Re: look tabel
 

Dear Thomas,

thank you. It is clear to me now. What is that heat loss or gain. mean fraction and mean fraction variance is okay to me. what is heat loss or gain. could you expalin to me.

Thanks in advance

Re: look tabel
 

1- If u're studying an adiabatic domain (that means that you've not enable the energy equation and so the cells are not exchangin energy between them and with the boundaries) all the thermodynamic properties (temperature, density,...) of your cells are dependent just by mf and mf variance;

2- If you have enabled the energy equation, all of your cells exchange between them and with the boundaries energy: that means that the thermodynamic properties are funcion of mf, mf variance and of the value of heat exchanged by cells. Example: if you visualize temperature in function of mf with heat exchanged equal to 0 that means you're looking to the temperature a cell will have when the balance in that cell (heat loss = heat gained) is 0. Positive values mean that the heat gained by this cell is greater than the heat loss, negative values that the heat loss is greater than the heat gain. Clear?

Thomas