Turbulence and interpolation.

[woodfire]

Hello everyone,

I have been dealing with the results of wooden
compartment fire. I have some questions related to the results:

1. If we plot HRR or a temperature (device recorded) against time, we
see a kind of fluctuating curve ( like one shown in user guide,
section 16.2). Is this fluctuation a measure of turbulent nature of
fire? or is it simply due to coarse grids used in the simulation?

2. If we place a device to measure temperature at a point that is
midway between two grid points, for example, the grid spacing is 10cm
and a device is placed at a co-ordinate 1.25m, how will FDS calculate
or interpolate the values at such a point? If it does interpolate,
what kind of interpolation scheme is used in it?

Thank you for your concerns.



Regards,
Shankar,
Germany.

[Kevin]

> 1. If we plot HRR or a temperature (device recorded) against time, we
> see a kind of fluctuating curve ( like one shown in user guide,
> section 16.2). Is this fluctuation a measure of turbulent nature of
> fire? or is it simply due to coarse grids used in the simulation?

Turbulence, non-steady mass loss rate

>
> 2. If we place a device to measure temperature at a point that is
> midway between two grid points, for example, the grid spacing is 10cm
> and a device is placed at a co-ordinate 1.25m, how will FDS calculate
> or interpolate the values at such a point? If it does interpolate,
> what kind of interpolation scheme is used in it?

You get the temperature of the cell where the device is located. No
interpolation.
>