[esp-r] Re: Contaminant peaks

[Aizaz Samuel]

Radek,

The contaminant solver gives numerical inconsistencies with certain model 
configurations. Try going to a smaller time step.

Regards,
Aizaz


On Monday 30 March 2009 04:40, Radoslaw Gorzenski wrote:
> Dear all,
>
> I simulate contaminant levels in single room with casual occupant gains and
> constant mass flow rate component. I use #6 “personal CO2 emission” as a
> source/sink model in *.ctm file. Time steps are 6 minutes for both zone and
> contaminant simulation. With single period in *.opr file the contaminant
> level is a straight line of proper value. As I try to use more periods in
> *.opr file - even with same gains in each period I get strange peaks in
> contaminant level. I put the diagrams with the contaminant value for 1, 2,
> 3, 4, 6, 8, 12 and 24 periods a day on www:
> http://www.gorzen.poznet.com.pl/espr/peaks.htm. My model is also available
> to download: http://www.gorzen.poznet.com.pl/espr/cont.zip
>
> Something wrong with my model?
>
> Below are some lines from my *.opr file with 4 periods a day.
>
>      4   # number of casual gains in day type: weekdays
> # type, start, stop, sens, latent, rad_frac, conv_frac
>     1,   0,   6,    540.0,    180.0, 0.500, 0.500
>     1,   6,  12,    540.0,    180.0, 0.500, 0.500
>     1,  12,  18,    540.0,    180.0, 0.500, 0.500
>     1,  18,  24,    540.0,    180.0, 0.500, 0.500
>
> Flow is constant all the time, gains are the same in all periods. What is
> wrong?
>
> The only way I see to do it correctly is to add source as #6 personal CO2
> emission model answering no to the questions "Take metabolic rates from
> occupancy casual gains (defined in operation files)" and then to describe
> the number of people, activity level and occupation time. Then it works
> proper, without any peaks. But it is not the solution. I can not simulate
> separate CO2 emissions for weekdays and Sundays.
>
> Regards,
> Radek Gorzenski