[Bldg-sim] CFD Software for Built Environment

[fazia.alitoudert at daad-alumni.de]

Hello all,

I need to know the wind speed and wind direction at several heights  
close to facades of a building which is surrounded by other buildings.  
I need this info later for an indoor energy simulation. I am thinking  
of using ENVI-met for this but it is a bit complicated and requires  
many runs.
... so I have very basic questions on CFD: can a CFD simulation be run  
for a period of time or is it limited to a specific time? is it  
possible to make a simulation for one year on an hourly basis i.e.  
8760 hours with the corresponding series of wind speed and direction.  
if yes, how time-consuming will it be? What are actually the main  
inputs needed by a CFD model?
is there any useful weblink to this issue?
Thanks,
Regards,Fazia



Zitat von "Costola, D." <D.Costola at tue.nl>:

>
> Hi Claire and Paul,
>
> Regarding CFX versus Fluent, my experience is that the "standard"   
> pre processing tools are quite different.
>
> Gambit, the standard pre-processing tool for Fluent, is as   
> user-friendly and powerful as CFX-Ansys.
> Just one example:
> On CFX (even the old CFX-Build) is relatively simple to create   
> unstructured meshes with good control and, very important, the prism  
>  layer in the solid boundaries. I couldn't produce the same meshes   
> using Gambit.
>
>
> Other important difference is the simulation automation process.
> On CFX the variables have meaningful names, and a lot of things can   
> be done using simple text files and the graphic interface. On Fluent  
>  you need to compile small programs with complex syntax even for   
> routine tasks such as create an inlet profile.
>
>
> Finally, no matter the program you use, spend some time reproducing   
> benchmark results to assure that you have mastered the program.
> My experience is mainly in outdoor simulation, where you have some   
> nice guidelines and benchmark data:
>
> http://www.costc14.bham.ac.uk/documents/Wg2/FinalDocument.pdf
>
> http://www.mi.uni-hamburg.de/fileadmin/files/forschung/techmet/cost/cost_732/pdf/BestPractiseGuideline_1-5-2007-www.pdf
>
> http://etheses.nottingham.ac.uk/archive/00000091/01/TongYangThesis2004.pdf
>
>
> About the benchmark data/cases for indoor flow I don't know.
>
>
> Regards
>
> Daniel Cóstola
> TU/e
> Department of Architecture, Building and Planning
> Den Dolech 2 - Vertigo 6.16 - P.O Box 513 - 5600 MB Eindhoven - The   
> Netherlands
> Phone +31 40 247 5760
> Fax +31 40 243 8595
> d.costola at tue.nl
>
>
>
>
>
> -----Original Message-----
> From: bldg-sim-bounces at lists.onebuilding.org   
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Paul   
> Carey
> Sent: donderdag 11 september 2008 16:02
> To: 'Claire Das Bhaumik'
> Cc: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] CFD Software for Built Environment
>
> Claire,
>
> Not a great deal of difference as far as I know.  My friend at Buro Happold
> uses CFX instead of Fluent without any problems on the work he does.  It's
> possibly more tightly integrated than Fluent in ICEM or AI workbench at a
> guess as they've had it longer.  As far as I know it's also cheaper and
> thats got to be a good aspect as if it can do more or less the same for less
> money I know which I'd be getting.  There are probably differences in the
> turbulence models available, etc but without looking into a detailed
> breakdown of features I can't really help there.
>
> Regards
> Paul
>
>
>
> -----Original Message-----
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Claire Das
> Bhaumik
> Sent: 11 September 2008 09:48
> To: Paul Carey
> Cc: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] CFD Software for Built Environment
>
> Any idea about ANSYS CFX?
>
>
>
> ANSYS own both codes now and tell me that CFX can do everything that Fluent
> can do and recommended it to me really in preference to Fluent for building
> applications. What's the difference?
>
>
>
> Thanks,
>
> Claire
>
>
>
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Paul Carey
> Sent: 10 September 2008 15:25
> To: 'antixs antixs'
> Cc: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] CFD Software for Built Environment
>
>
>
> Antixs, et al
>
>
>
> Airpak is okay and is perfectly adapted to HVAC applications as it includes
> fan details, etc allowing you introduce swirl, etc.  It is expensive for
> what you get though.  It has improved, but the gridding was fairly rough and
> ready if you get complex geometry and can throw a wobbly if you are doing
> external flow analysis for things like pedestrian comfort assessments where
> you could need large variance in your grid cell size.  If you are doing
> rooms, etc you'll be fine.  I'd agree with Kai's comments though.
>
>
>
> Not used FloVent.  It's quite pretty from memory, it's outputs are well
> suited to HVAC work and make the whole CFD (Colour For Directors) stand up.
> Whether it is good for complex analysis I'm not sure and will have to leave
> that to others to comment on.
>
>
>
> CHAM's flair is HVAC specific and there is even a link with Hevacomp so if
> you've done your room calculations in that then there is a reduced version
> which will let you do some basic flow analysis.
>
>
>
> The problem with most of these simplified tools however tends to be the
> gridding which has a tendancy to let them down and so convergence of
> solutions can be hard to achieve.  It really does depend on what you are
> going to use it for and what sort of problems.
>
>
>
> Sorry about copying your message below to the list Kai, but I think others
> will lose the thinking of the thread and my comments as well, hope you don't
> mind.
>
>
>
> Cheers
>
>
>
> Paul
>
>
>
>
>
> From: Kang, Kai [mailto:Kai.Kang at jacobs.com]
> Sent: 10 September 2008 14:52
> To: antixs antixs; Paul Carey
> Subject: RE: [Bldg-sim] CFD Software for Built Environment
>
> Antixs,
>
>
>
> Both Airpak and Flovent are customized CFD programs for building HVAC
> applications.  Airpak wraps around the basic Fluent solver, and provides a
> user-interface that is much more geared towards building engineers, as well
> as some additional functions that is only available with Airpak, such as
> solar heat gain.
>
>
>
> I have some experience with Airpak a while ago, being a Fluent user for many
> years, I did not find any problem of learning the program and will say an
> engineer without prior experience should be able to pick up the modeling
> pretty quickly - the problem, however, is that if there is any issue with
> the model, such as if the solution is diverging, it is very difficult to
> "debug" the model in Airpak.  I assume the same would be for Flovent, so in
> essence I would say they provide the easiness in "cookie-cutter"
> applications.
>
>
>
> I am not copying this to the entire mailing list, as I may be talking a bit
> too specific.
>
>
>
>
>
> Regards,
>
> Kai
>
>
>
> ________________________________
>
> From: antixs antixs [mailto:antixs.antixs at gmail.com]
> Sent: 10 September 2008 14:36
> To: Paul Carey
> Cc: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] CFD Software for Built Environment
>
> Paul,
> Thanks for such detailed information! They are really helpful. Do you have
> any experience with Airpak and Flovent? Heard that these two tools are
> specially tailored for built environment.
>
> Thanks again.
>
> antixs
>
> On Wed, Sep 10, 2008 at 4:39 PM, Paul Carey <Paul at zed-uk.com> wrote:
>
> Antixs
>
>
>
> I think this depends largely on your budget and proficiency.
>
>
>
> If you want to go full on with CFD, then I'd suggest Fluent
> (http://www.fluent.com/) everyday.  It is very widely used and well trusted
> tool.  ICEM is a good meshing tool, but we like Pointwise and Gridgen for
> it's meshing simplicity.
>
>
>
> Other than that, I know CCM+ from CD-Adapco (http://www.cd-adapco.com/) is
> very good too.  Makes the job quite easy.  These tools are very expensive
> though.
>
>
>
> If you want the same sort of capability and are willing to use mainly text
> input then I'd suggest OpenFoam (http://www.openfoam.org) - a very powerful
> open source CFD tool.  You could use something like pointwise to mesh it,
> output a fluent case file and then openfoam has it's own fluent case file
> converter program which you could use to then convert it and process it.
> You'd probably need a decent post processor too, but clearly then you are
> only paying for those programs as openfoam itself
> is free.    If you can do it all by text then you wouldn't need to pay
> anything at all.  It will require you to use Linux though.  I saw a
> pre-compiled bootable live CD distro of this recently which was quite
> impressive so it allows you to check it out just by inserting CD into
> computer and booting to it.  The link for that is:
> http://www.caelinux.com/CMS/
>
>
>
>
>
> Of the cheaper and possibly more usable programs for quick built environment
> analysis.  Cham Pheonics (http://www.cham.co.uk/)  is good value for money.
> It's Flair add on is pretty simple to use.  I'd still personally get a good
> CAD program to make sure your geometry is spot on before importing it, but
> then it would do the job well.  A lot of companies use it becasue of it's
> relative simplicity and good price.
>
>
>
> Another which is aimed at non-CFD experts is DesignBuilder CFD
> (http://www.designbuilder.co.uk/).  It is in beta test stage and looks
> promising.  It'll be great for simple stuff.  Wouln't recommend anything
> that uses just cartesian grids for complex jobs, but for the large majority
> of jobs it will suit, especially if it's internal room flows, etc.  Should
> be quite competitive on the price too.
>
>
>
> Hope that helps.
>
> Regards
>
> Paul
>
>
>
> Dr Paul Carey
> Director
>
> Zero Energy Design Ltd
> 10A Portland Place
> 2-22 Mottram Road
> Stalybridge
> SK15 3AD
> UK
>
> T:  +44 0161 3386200
> F:  +44 0161 3031281
> M:  +44 0789 4098012
> E:  paul at zed-uk.com
>
> http://www.zed-uk.com/
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> ________________________________
>
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of antixs antixs
>
> Sent: 10 September 2008 05:13
>
>
> To: bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] CFD Software for Built Environment
>
>
>
> Hi all,
>
>
>
> Just wonder what CFD softwares are popularly used for analyzing built
> environemnt in architect/MEP consulting firms? Also which one is relatively
> eaiser to use?
>
>
>
> Many thanks.
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.169 / Virus Database: 270.6.19/1661 - Release Date:
> 9/10/2008 6:00 AM
>
>
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.169 / Virus Database: 270.6.19/1664 - Release Date:
> 9/10/2008 6:00 AM
>
>
> ________________________________________________________________________
> This e-mail has been scanned for all viruses by Star. The service is powered
> by MessageLabs. For more information on a proactive anti-virus service
> working around the clock, around the globe, visit:
> http://www.star.net.uk
> ________________________________________________________________________
>
> ________________________________________________________________________
> This e-mail has been scanned for all viruses by Star. The service is powered
> by MessageLabs. For more information on a proactive anti-virus service
> working around the clock, around the globe, visit:
> http://www.star.net.uk
> ________________________________________________________________________
>
>
>
> ________________________________
>
>
> This message (and any associated files) is intended only for the use of the
> individual or entity to which it is addressed and may contain information
> that is confidential, subject to copyright or constitutes a trade secret. If
> you are not the intended recipient you are hereby notified that any
> dissemination, copying or distribution of this message, or files associated
> with this message, is strictly prohibited.
> If you have received this message in error, please notify us immediately by
> replying to the message and deleting it from your computer. Messages sent to
> and from us may be monitored.
>
> Internet communications cannot be guaranteed to be secure or error-free as
> information could be intercepted, corrupted, lost, destroyed, arrive late or
> incomplete, or contain viruses. Therefore, we do not accept responsibility
> for any errors or omissions that are present in this message, or any
> attachment, that have arisen as a result of e-mail transmission. If
> verification is required, please request a hard-copy version. Any views or
> opinions presented are solely those of the author and do not necessarily
> represent those of the company.
>
> The ultimate parent company of Scott Wilson Group is Scott Wilson Group plc.
> Registered in England No. 5639381
> Registered Office: Scott House, Alençon Link, Basingstoke, Hampshire
> RG21 7PP
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.169 / Virus Database: 270.6.19/1665 - Release Date: 9/11/2008
> 7:03 AM
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to   
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to   
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
>