[esp-r] Re: flow components ESP-r

[Baharvand, E.]

So, can I conclude that it is not possible to define sort of an fictitious flow component, which doesn't influence the flow at all? 
That I could possibly use the flow conduit (for duct or pipe), I knew already. But my intention is to avoid using the f (for friction) and the C (for distortion) first, and considering the "channel" having no influences (ideal channel) on the fluid flow. The same as - but different implementation -  it is done for fictitious constructions for connections between thermal zones. 

For example, If I choose C and f being zero, than the square root of something infinite become infinite and the equation of general flow conduit will give mathematical errors (see the equation Clark book , second edition, page 132). Thus, I can't either implement a ideal channel by doing so. 

That a channel is without pressure drops due to friction and distortions is not practically realistic, but the predications of such a approach I would like to use for some validation work (If this appears to be possible!).

Kind regards,
Ehsan Baharvand
________________________________________
From: Achim Geissler [achim.geissler at intergga.ch]
Sent: Wednesday, October 21, 2009 2:09 PM
To: Baharvand, E.
Cc: esp-r at lists.strath.ac.uk
Subject: RE: [esp-r] Re: flow components ESP-r

In addition to the below, the tester model

        bld_hc_ISO15099

features a kind of stack, i.e. a bottom and top mixing zone with a one-zone
"channel".

Regards
Achim


-----Original Message-----
From: esp-r-bounces at lists.strath.ac.uk
[mailto:esp-r-bounces at lists.strath.ac.uk] On Behalf Of Jon Hand
Sent: Mittwoch, 21. Oktober 2009 13:53
To: Baharvand, E.; esp-r at lists.strath.ac.uk
Subject: [esp-r] Re: flow components ESP-r


A question about flow components:

The critical phrase below is 11m height.  To get a stack effect many users
would
use a conduit and provide a hydraulic diameter and some (in your case) small
local loss factor and an 11m length.  You would make sure you had a bounding
wind pressure node at the top of the stack.  When linking in the component
you
would be careful to assign the 'delta heights' so that the bouyancy
calculation
would know there is a height difference.

And many other users would also prefer to create the stack as a thermal
zone (so there are real temperatures within the stack) and associate the
flow component with the stack zone.

Users also may have the opinion that there will be temperature differences
within the 11m stack and they will make several thermal zones as well
as flow components and link them together.

If you go with one or more zones you will then have nodes associated with
each of the stack zones and if you wanted to use a simpler opening type
as the connecting flow component you could try that out (again making
sure that the delta-height values were correct).

And you might make some alternative models to try out different approaches
and see which one seemed to work better.

Currently there is not an exemplar model about stack designs.  Perhaps
someone in the community has one that they might want to share?

-Jon Hand

-Jon Hand
________________________________________
From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] On
Behalf Of Baharvand, E. [e.baharvand at student.tue.nl]
Sent: 21 October 2009 10:04
To: esp-r at lists.strath.ac.uk
Subject: [esp-r]  flow components ESP-r

Dear all,

I would like to raise the next question about flow components used in air
flow network in ESP-r.

In my study, where for the use of AFN is required, I need to choose from the
flow components types exist in ESP-r database. The list of these components
one can find - among other sources - in Clark J.A. " Energy simulations in
building design"  on page 132 Table 5.4.

I'm considering a rectangular (2mx0.25m) cross section area of 11 meter
height in which the stack effect is predicted. Considering this application,
which flow components can be considered, if:
- assuming that there is no flow frictions/resistances in this channel
(because I would like to consider the channel as ideal);

Beside above, in Clark's book Table 5.4. on page 132: what means the
component 'Ideal (frictionless) open' ?

Thanks in advance.

Kind regards,
Ehsan Baharvand
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