[esp-r] Re: Air flow network simulation without building and plant

Tue Oct 3 15:54:31 BST 2023

Thanks Jon for your explanation and advice.

I need to configure and simulate examples with supply, exhaust and combined
supply and exhaust systems for teaching purposes only. The examples will be
explored by mechanical engineering students. The focus is on sizing and
evaluating the performance of the ventilation system and its components,
and the idea is to configure the flow network in enet and simulate it in
mfs without including the building and plant, at least at the beginning.
Initially, the idea is to understand how enet and mfs work together.

The flow network configured in enet is:

[image: image.png]

The configuration file sup_vent is attached to this mail.

I will look at the material you suggested.

Best regards,

Clodoaldo.

*Prof. Clodoaldo de O. Carvalho Filho, Dr.*
Universidade Federal do Ceará
Depto. de Engenharia Mecânica
Lab. de Eficiência Energética no Conforto Ambiental - Coordenador
ASHRAE Fortaleza Student Branch - Advisor

Em seg., 2 de out. de 2023 às 05:14, Jon Hand <jon at esru.strath.ac.uk>
escreveu:

> Hello Clodoaldo,
>
> The error is what we call a string buffer overflow - more characters are
> being written to
> a string variable than it can hold.  The error is happening when it is
> trying to compose
> a menu.  We would need to do some debugging while attempting to create the
> same
> network to get past this.  To help us with this can you send a sketch of
> the network
> you wanted to create along with the names of the entities that you tried
> to use so
> the fault can be duplicated?
>
> Until this can be done why not try an alternative approach?
>
> It seems like a simple network.  Is there a reason you do not use a simple
> box model
> of a thermal zone with it? This will us the much more common bps simulator
> to
> solve both the zone and the flow network - so you get the dynamics.
>
> There are a number of YouTube videos which show aspects of setting up flow
> networks.  Look in the ESP-r tutorials and ESP-r demonstrations videos
> here:
>
> https://www.youtube.com/@jon.in.glasgow1989/playlists
>
> <https://www.youtube.com/@jon.in.glasgow1989/playlists>
> jon.in.glasgow <https://www.youtube.com/@jon.in.glasgow1989/playlists>
> www.youtube.com
> There is also a chapter all about flow networks on the Strategies web page:
>
> http://contrasting.onebuilding.org/Strategies/Index.html
>
> Regards, Jon Hand
> ------------------------------
> *From:* esp-r-bounces at lists.strath.ac.uk <esp-r-bounces at lists.strath.ac.uk>
> on behalf of Clodoaldo Carvalho Filho <clodoaldo at ufc.br>
> *Sent:* 01 October 2023 19:54
> *To:* esp-r at lists.strath.ac.uk <esp-r at lists.strath.ac.uk>
> *Subject:* [esp-r] Air flow network simulation without building and plant
>
> Hi you all,
>
> I need to configure and simulate a simple supply ventilation system. The
> system has a fan connected to the zone by a supply grill (local pressure
> loss), and the zone is connected to Exhaust by an exhaust grill (another
> local pressure loss).
>
> I am trying to do it in ESP-r, but I am experiencing some difficulty
> configuring the air flow network (afn) in enet and simulating it without
> building and plant in mfs. The afn has 4 nodes, 3 components and 6
> connections (config file attached).
>
> enet crashes every time I try to change "i cross-sectional area (m^2)" in
> X11 interface and returns the following:
>
> At line 221 of file netwedit.F
> Fortran runtime error: End of record
>
> Error termination. Backtrace:
> #0  0x7fc546e23960 in ???
> #1  0x7fc546e244d9 in ???
> #2  0x7fc546e2510f in ???
> #3  0x7fc547077360 in ???
> #4  0x7fc54708422c in ???
> #5  0x7fc54707ab84 in ???
> #6  0x7fc54707ae05 in ???
> #7  0x562913fcb789 in ???
> #8  0x562913f7a360 in ???
> #9  0x562913f5a7be in ???
> #10  0x7fc546a29d8f in __libc_start_call_main
> at ../sysdeps/nptl/libc_start_call_main.h:58
> #11  0appreciatedx7fc546a29e3f in __libc_start_main_impl
> at ../csu/libc-start.c:392
> #12  0x562913f5a8a4 in ???
> #13  0xffffffffffffffff in ???
>
> I am not sure the afn configuration is consistent with what mfs needs to
> run ok. The pressures calculated at the internal nodes are zero and mass
> flows at connections have different values (one of them is zero) when it
> should be equal. Why?
>
> Is there an example of a mass flow network without building and plant in
> ESP-r training directory?
>
> I am using the Network tool of ESP-r V13.3.16 of 1 June 2023, built on
>
>   Platform -         x86_64:Linux:6.2.0-33-generic
>   Compilers -        gcc/g++/gfortran
>   Graphics library - X11
>   XML output -       Supported
>
> Any clue to help me succeed in simulating this afn will be appreciated.
>
> Best regards,
>
> Clodoaldo.
>
> *Prof. Clodoaldo de O. Carvalho Filho, Dr.*
> Universidade Federal do Ceará
> Depto. de Engenharia Mecânica
> Lab. de Eficiência Energética no Conforto Ambiental - Coordenador
> ASHRAE Fortaleza Student Branch - Advisor
>
>
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