<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Mostapha<div><br></div><div>looking at your .afn, I think the problem is that all your connections to external nodes are in one zone (01).</div><div><br></div><div>To get an afn up and running, a basic requirement is that for every zone you can go from an external node to a zone ... to >the< zone ... to a zone ... and so on and then to a (different) external node again. I think this does not hold for your afn. Add a connection type "tiny", e.g. a crack a factor 10 or 100 smaller than your _crk types and connect the lowermost zone(s) to an additional external node.</div><div><br></div><div>Then something should happen and there should be pressure differences.</div><div><br></div><div>Best</div><div>Achim</div><div><br></div><div><br></div><div><br></div><div><br><div><div>On Jun 9, 2010, at 2:47 PM, Mostapha Sadeghipour wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Hello Aizaz,<br><br>I think the problem is not the node heights in my case, however I'm not sure. The .afn file is attached.<br><br>Regards,<br><br>Mostapha Sadeghipour<br><br><div class="gmail_quote">On Wed, Jun 9, 2010 at 3:54 PM, Aizaz Samuel <span dir="ltr"><<a href="mailto:aizaz.a.samuel@strath.ac.uk">aizaz.a.samuel@strath.ac.uk</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Look up how node heights are defined in exemplars>network<br> ventilation>alternative facade vent.....<br> <br> Theory can be found in Jan Hensen's thesis (section 4.3.2) available at<br> <a href="http://www.esru.strath.ac.uk/publications.htm" target="_blank">http://www.esru.strath.ac.uk/publications.htm</a><br> --<br> Dr Aizaz A Samuel<br> Department of Mechanical Engineering<br> University of Strathclyde<br> M324 James Weir Building<br> 75 Montrose Street<br> Glasgow, UK<br> G1 1XJ<br> <br> T:+44 141 548 5765<br> F:+44 141 552 5105<br> <div><div></div><div class="h5"><br> On Wednesday 09 June 2010 11:28, Mostapha Sadeghipour wrote:<br> > Dear esp-r users,<br> ><br> > I'm modeling an atrium with a closed glass roof. The atrium has nearly 16m<br> > height and it only connects to the outside through 3 cracks on the roof. I<br> > divided the atrium into 5 vertical zones, and adjacent vertical bypass<br> > zones. They are connected to each other through fictitious faces.<br> ><br> > Common orifice components connect zone nodes to each other vertically, and<br> > door component connects zone nodes to bypass nodes horizontally. The<br> > attached image shows the Air Flow Network in my model more clearly.<br> ><br> > I supposed that esp-r includes the stack effect whenever delta height<br> > between the nodes and the component is not zero. So I expected to have a<br> > stack pressure in the vertical connections. But when I check the results<br> > the stack pressure in the connections are zero!<br> ><br> > I'm also curious how esp-r consider the stack effects and the gravity? The<br> > components dP are set manually and there is no "g" in the equations? Where<br> > I can find the PSTACK equations that is used to calculate DP:<br> > DP=PRES(IDPS)-PRES(IDNE)+PSTACK(ICNN).<br> ><br> > Thanks in advance.<br> ><br> > Mostapha Sadeghipour<br> <br> </div></div></blockquote></div><br> <span><atr.afn></span>_______________________________________________<br>esp-r mailing list<br><a href="mailto:esp-r@lists.strath.ac.uk">esp-r@lists.strath.ac.uk</a><br>http://lists.strath.ac.uk/mailman/listinfo/esp-r</blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><a href="mailto:achim.geissler@intergga.ch">achim.geissler@intergga.ch</a></div><div><br></div><div><br></div></div></span><br class="Apple-interchange-newline"> </div><br></div></body></html>