[esp-r] Re: Simulation with temporal file, clarification of SURTM items

[Jon Hand]

I will attempt to explain the idea of SURTM again.  If you have an physical experiment
and a virtual experiment (simulation) it is often useful to compare specific temperatures
in the experiment with their equivalent in the simulation model.  SURTM items hold
timestep measured data.  In the results analysis tool you can plot the simulated
surface temperature and also ask to plot the measured data held in the SURTM
temporal item.  You could also use res module statistics functions on the SURTM
data.

The graph showing different sky temperature measurement was very interesting.
It looks like you (or your group) might have an interest in completing the implementation
of the sky temperature temporal file link.

-Jon Hand
________________________________________
From: Lee, C. [C.S.Lee at tue.nl]
Sent: 25 October 2011 19:57
To: Jon Hand
Subject: RE: Simulation with temporal file

Dear John,

Thank you for your answer.

With SURTM option, I assigned all zero value at 's_roof' in bld_basic and I compared the same 's_ roof' temperature.
Maybe my program has some problems. I'll try it again.

-----------------------------------

Yes, It is the calculated data from measured clouded fraction, air temperature and water vapor pressure.

I am modeling greenhouse in The Netherlands and I found that sky temperature is a critical factor for thermal environment
in low-rise and huge roof surface greenhouse.
There is a greenhouse simulation program - KASPRO and they did empirical validation test with real greenhouse.
I compared ESP-r air temperature in simple greenhouse simulation model with KASPRO
and I found the air temperature is quite sensitive depending on sky temperature.

They offered me KASPRO weather data -they said 'measured'- and I made ESP-r weather file from it,
but the simulation result was different without consideration of cloudiness especially at night.
That's why I tried to use sky temperature option in ESP-r.
I attached a comparison result with different sky models in ESP-r and KASPRO

They said they calculated it based on Monteith's empirical research;
    1. An empirical method for estimating long wave radiation exchange in the Britsh Isles.
    2. Principle of Environmental physics.

Kind regards,

Chul-sung.




-----Original Message-----
From: Jon Hand [mailto:jon at esru.strath.ac.uk]
Sent: Tuesday, October 25, 2011 6:19 PM
To: Lee, C.; esp-r at lists.strath.ac.uk
Subject: RE: Simulation with temporal file


The sky temperature option in the temporal file is work-in-progress.  It is
not yet connected to the solver.  We should probably update the
documentation to make this clear.  It might not take a lot of work
to use the data - and no one has yet done it.

There are several sky temperatures calculated within ESP-r (there is a trace option
in the simulator that will report on these). Currently you would have to alter the
source to enable one of the alternative sky temperature methods.

The SURTM is design to allow you to plot/report measured values so that it
is easier to compare them with simulated values.  The simulator does not use SURTM
items. The results analysis module knows how to include them in reports or graphs.
It looks like we need to revise the help messages further to make this clear.

Surface temperatures are the result of heat flows (the energy balance at each
surface) rather than an input value.

If you have specific sky temperature data do you have matching dry bulb and
humidity data?

Regards, Jon Hand