Wind analysis by grasshopper

Hi all,

I am currently designing a hotel and trying to analysis wind by grasshopper. But don't know how to it.

Please help me out. thanks.

Replies to This Discussion

Permalink Reply by peter fotiadis on October 12, 2015 at 3:43am

Hmm ... wind simulation for LBS stress?, for panel detachment (negative pressure)? for what exactly?

Other than that and assuming that you know what Kangaroo1/2 are, have some fun with this attached (Kangaroo1 engine on duty) which is ideal for predicting what happens with the laundry (when exposed in balconies/roof: rather ultra chic I confess, he he).

Load R file first for the test cases (no internalized data).

Attachments:

Gone_with_the_wind_V1.3dm, 91 KB
Gone_with_the_wind_V1.gh, 144 KB

Permalink Reply by Aik GH on October 12, 2015 at 9:14am

Thank you so much for the tips.

I am trying to analysis lateral load on hotel tower surface and find a suitable form which can effectively reduce the wind load on the hotel facade.

Permalink Reply by peter fotiadis on October 12, 2015 at 9:42am

Hmm ... this is very tricky (i.e. another "simple case", he he):

1. Assuming that with some way you achieve "min" lateral forces ... for one direction ... but since wind has other directions in mind as well you are searching some approximation ( a "mean"): say the hole that KPF did on top on that famous building? On the other hand there's always Plan Z: what SOM did in Dubai (Burj Khalifa).

2. Or you have a repertoire of possible shapes in mind and you try to find the most "effective" one? This requires some custom code (although apparently not required) in order to manage the variants (otherwise you'll get lost in a sea of parameters).

3. But even if this, this and that are on hand ... by what means can you measure/evaluate the cost VS benefits? I mean that (supposedly) a "curvy" surface MAY yield less lateral forces ("proportional" to tower's height as well) ... but if it costs an arm and a leg (most probably, see 4 as well) ... "stiffening" the LBS MAY yield a better solution (budget wise).

4. But even if this, this and that are on hand ... cost analysis is in the end of the pipeline (when in the final level of study) meaning that in 99.9999% of cases it's toooooo late for any meaningful change/variation.

In a nutshell this is a very challenging problem not due (mostly) to the wind effect but primarily due to the holistic approach required for keeping variants/alternatives (and their real-life cost) in some kind of "fitness".

If this is a real-life project and you are not very experienced with, say, C# (or other) ... i WOULD STRONGLY RECOMMEND to avoid that kind of puzzles (obviously having in mind real-life, real-money, real-buildings, real-studies etc etc etc).

Permalink Reply by Aik GH on October 12, 2015 at 11:16am

Thank you so much for your detailed response. I really appreciated it.

I am pretty new to Kangroo and have no basic understanding for how c# works.

And this is an architecture school studio project, not so much about creating cost effective buildings.

I just wanted to know how to simply simulate wind load on the hotel tower facade. If there is any similar case study, that would be extremely helpful. thanks again.

Permalink Reply by peter fotiadis on October 12, 2015 at 12:33pm

OK, I'll make some "abstract" demo (and omit all the things that matter, he he). Forget C# as well.

But jokes apart ... er ... going after the academic aspect of things in Architecture (for instance: cost, what cost?) is a very bad habit: it makes you gradually adopt the idea that real-life is just the next step: in fact is 1++M miles away.

Until the demo arrives here's a classic "comparison" between good-old "boxy" things (obviously non "aerodynamic" - unless KPF style of holes are used or a drastic reduction on floor areas) and the new holly grail (the curvy WOW blob, that is). Of course any blob's skin is "emulated" via planar "facets" ... but the catch is that the angles between "facets" vary and that means money (a lot). For instance:

This is a Schuco classic non adjustable facade detail for boxy facades:

And this is a hideously expensive custom patented adjustable system capable to "follow" variations in "facet" angles (dihedrals) - up to a point, that is:

For a 300m tower the difference in facade's cost MAY be IN EXCESS of 20M.

In the mean time post your facade.

Permalink Reply by Kim hauer on October 12, 2015 at 1:46pm

Rule No1: If you want a reliable curtain wall system, don't pick the low bidder :) Unfortunately I could no longer find pictures of 90% of the glass panels having been replaced with plywood. :(

Permalink Reply by Aik GH on October 12, 2015 at 3:45pm

you are awesome man. thank so much.

Please see the attachment for the massing that i got for my studio project. and I wanted to do a curve on surface so that it looks cool.

Attachments:

Elevation.pdf, 2.7 MB

Permalink Reply by peter fotiadis on October 13, 2015 at 12:47am

Well...

... I need a parametric thingy NOT a pdf (Kangaroo is not that intelligent to "translate" an image to ... er ... something; but maybe this is the ultimate challenge for Daniel after all, he he).

Permalink Reply by peter fotiadis on October 13, 2015 at 4:22am

Well... I was starting doing the demo (that have real-life meaning for towers taller than, say, 100m)... but all of a sudden I realized that I was using K2 (which is open source) and ... er ... no components at all (C# , that is). Obviously this is a no-no > the wrong thing to do > back to the drawing board.

In the mean time get these 2 that are related with the issue (but how? I have no idea, he he).

The flatten (get the flying laundry back in a "stationary" state, he he) is challenging because ... if you change some mysterious things it turns ultra paranoid.

The other (intro to 3d grids) has a broad "repertoire" depending on your choices (and it doesn't comply with your grid inputs all the times - blame AI, he he):

Attachments:

Bend_a_grid_V1l.gh, 142 KB
Flatten_V1.gh, 39 KB

Permalink Reply by Aik GH on October 13, 2015 at 5:53am

you are awesome, man. ton of useful inputs.

I have not started my script yet. but I just wanted to have a similar demo from which I can get what I need. For example, my tower is 500' with the base footprint of 80'by 112', rectangle shape.

Permalink Reply by peter fotiadis on October 13, 2015 at 8:10am

Hmm ... 170m means a 40 floor thingy. Indeed wind has some effect.

Accidentally I have a C# (but you can replace it with components at later time) that does a 3d grid with 666 ways (and a variety of other "minor" things required). So one realistic approach is to create a neat non twisted LBS (and room layout) and then mimic the YAS (Google that) hotel example:

...where the WOW (and "cheapo") geodome like envelope/skin is there only for decorative purposes (putting 1Z LED's adds to the "pleasure").

And since we engineers ... we are professional liars (and villains) we can provide as excuse for that (a bit kitsch) curvy thingy by claiming that is ...er ... simply ... hmm ... the next generation of PV nano-stuff. Spend some time here:

http://www.solaronix.com/

So the 1M idea is: dress a humble skeleton with a WOW vertical "geodome" (you need a Ball Pivot Algorithm for that, not a problem) and win the 1st prize, the caviar, the girl and maybe that Ferrari.

I hear you: Can we skip the wind part and go straight to the core of the matter? (function follows form, that is).

Moral: Lies and then some (the more the better).

He, He.

Permalink Reply by Aik GH on October 13, 2015 at 9:51pm

You are awesome, man. I like the way you talk and think. Interesting.

I have followed the function follows form. all the functional spaces are figured out nicely. Now, i am at the point where i need to some aesthetic skins....hope you understand my feeling.

what if I play with solar angle, daylight, and view? any case study follow? thanks