How to model a hollow brick - Validation process.

Alles zu DELPHIN, dem Programm zur hygrothermischen Bauteilsimulation.

Moderatoren: ghorwin, fechner, ruisinger

Antworten
NayaraUSTUTT
Beiträge: 6
Registriert: Do 7. Mär 2019, 10:20

How to model a hollow brick - Validation process.

Beitrag von NayaraUSTUTT » Di 12. Mär 2019, 09:03

Hello, Delphin team,

I am working with a 2D Delphin model that needs to be validated with data from a test performed under controlled conditions. It is a wall made of hollow bricks, some of them equipped with several sensors, including its cavities (photo attached).
However, some doubts arose regarding the modelling of this brick/test:

1) Would it be permissible a model simplification, omitting the brick cavities?
2) If they have to be modelled, what would be the best way to construct such geometry?

The main concern is related to the comparison of the data (Temp. + RH) coming from the sensor located inside the cavity and its corresponding outputs from the model. Should the boundary conditions be the same, or would it be acceptable the option 1 approach?

Hope someone can elucidate the case.
Thanks in advance.

Best Regards
Nayara Sakiyama

fechner
Beiträge: 35
Registriert: Mi 19. Dez 2018, 08:32

Re: How to model a hollow brick - Validation process.

Beitrag von fechner » Di 12. Mär 2019, 09:54

Hello,

You can simplify the hollow bricks to solid ones. You need to create material properties for this hollow bricks that takes the cavities into account. You have two possible methods:
1. measure the values with the complete bricks (complicated)
2. make separate calculations with the hollow bricks using material properties of the solid brick material itself and air cavities in order to find out the material parameter for the complete brick.
In case you use the second method you have to recalculate some of the experiments used for material property measurements. Mainly for:
- thermal conductivity
- vapor transmission (cup tests)
- water uptake experiment.
What for material properties do you have?

Of course you can skip such simplifications and model the brick wall as it is including cavities. This leads to bigger models and longer calculation times.

Best regards
Heiko Fechner

NayaraUSTUTT
Beiträge: 6
Registriert: Do 7. Mär 2019, 10:20

Re: How to model a hollow brick - Validation process.

Beitrag von NayaraUSTUTT » Di 12. Mär 2019, 10:35

Thank you so much for your answer.

Unfortunately, these are the only information available regarding the Brick properties: https://www.leipfinger-bader.de/wp-cont ... W10-PLAN-1. pdf [/ url]

Anyway, I am thinking of testing the two approaches: simplified model and with cavities, to verify their results differences. Either way, I believe simplifications would be needed.

fechner
Beiträge: 35
Registriert: Mi 19. Dez 2018, 08:32

Re: How to model a hollow brick - Validation process.

Beitrag von fechner » Di 12. Mär 2019, 13:16

The information about the brick are very limited. In this case you have to look in our material database in order to find a similar brick. Maybe the bricks from company Schlagmann can be the right choice.

Antworten