Material Editor - Manual

This area displays the material name, material category and transport capabilities (color-coded).

The material name, like all other descriptions, can be specified in several languages. In the main view, the texts are always displayed in the language of the operating system. If this language is not available, the text is displayed in English.

To edit the text in the other languages you should click the button with 3 dots on the right. Then a corresponding editor will open.

In this dialog the text can be entered directly in English, the language of the operating system and another language. The third language can be selected in the selection box above. The default language is Italian. If English is the language of the operating system only two languages will be shown.

The category can be selected from one of 13 types:

The transport properties are displayed in color-coded form. A particular transport type can only be taken into account if all the necessary properties are available. Furthermore, this special transport must not be switched off by using a flag (section Identification). The colors have the following meaning:

The transport processes for salt and VOC are currently not supported by the material editor.

The basic parameters represent a selection of data which on the one hand should help to select a concrete material from the database and on the other hand can serve as parameters for transport and storage models. Some parameters are derived from the models themselves. These cannot then be changed directly. A description of all basic parameters can be found in the following table. In column 'Usage' one can find the transport and storage processes which are influenced by this parameter. If nothing is entered there, the parameter serves only for information and is not used in the simulations!

The material database format of DELPHIN supports even more basic parameters, but these are not supported by the editor. You can find more information here: https://nbn-resolving.org/urn:nbn:de:bsz:14-qucosa-126274

The following figure shows the section of the editor for the basic parameters.

By checking the box 'Show all parameters' all possible parameters (see table) are displayed in the list, otherwise only those with a valid value are shown. If a number is marked yellow there, you can change this number. Some values can also be deleted. But this is only possible if this parameter is no longer needed (flags, models). You delete a parameter by deleting the value and then pressing ENTER. If this value cannot be deleted, the original value is re-entered.

The flags are located to the right of the basic parameters.

These have different effects and can be grouped as follows:

Transport flags:

If such a flag is set, the respective transport is no longer possible and all related parameters and models are no longer used (and can be deleted). If a material is both water tight and vapour tight, no parameters for moisture transport and storage is required. This is the case for materials such as glass, metals or solid plastics. The corresponding keywords for the material files are listed in brackets.

Material flags:

There are five buttons on the bottom of the material editor. These have the following effect:

The appearance of the model view depends on the selected section. The currently available sections are shown in [Main_Window_Sections]. The individual sections are described below.

In this example we are dealing with an internally insulated brick wall. In such a construction, the impermeability to driving rain plays a major role. If this is not the case with the original construction, it must be provided subsequently. In the case of a brick-faced façade, a hydrophobic coating is often applied.

What does hydrophobicity mean for the material? Ideally, the liquid water conductivity should be reduced without affecting the vapour transport. A hydrophobing agent, e.g. on a silicone basis, can be used here, which is applied to the outside of the facade. It penetrates several millimetres deep and changes the liquid water transport there. In Delphin, this can be modelled in such a way that an adapted brick material is used for an approx. 5 mm thick outer layer. How do you proceed?

After clicking on the copy button marked with the arrow, the following dialog appears

The chosen material was in the DELPHIN material database, which can be easily recognized by the reference (green arrow) that refers to the Material Database. To be able to change the material, it has to be copied. There are two possibilities for this:

The first button is used to copy material files from the database to another directory. The most suitable directory for this is materials in the project directory. This should be used here as well.
The second button is used to duplicate material files that are already outside the database. This is useful if you want to perform variant studies with several adapted materials.
After clicking the first button, another dialog appears:

Here you can enter a new name for the new material. By default, a number in square brackets is appended to the existing name. We change the name so that a hydrophobicity can be recognized.

After closing this dialog, you will return to the original dialog. Here you should change the display name and also the color to differentiate to the original material. Then you can close the dialog.

As a result, a new material can now be seen in the material list of the project.

The material is still shown in grey italics because it has not yet been assigned to the construction. Next, the liquid water conductivity has to be adjusted. To do this, open the material reference dialogue again by double-clicking on the material and then click the Edit button. The material editor opens. Here you select the Liquid Water Transport tab.

The picture shows the currently used guiding function. This brick has a Kl(Θl) function with a highest Kl value of -8.44log(s). In the basic data there is an Aw-value of 0.38kg/m²s^0.5 and a Kl_Eff of about 2*10^-9 s. A good hydrophobicity should reduce the Aw-value to at least a tenth (better to a hundredth) of the original value. We now change the Aw-value to 0.01 kg/m²s^0.5. All we have to do is double click on the value in the table, adjust it and then press ENTER. The whole function is then scaled down. The result is shown in the following picture:

As you can see, not only the Aw-value has changed, but also Kl_Eff, as well as the whole leading function. This material can now be accepted by clicking on Ok and then assigned to the construction.

When examining existing buildings, it often happens that the materials used there are not available in the DELPHIN database. Nevertheless, you still need the material characteristics so that you can calculate. Here, there are two procedures:

In this section variant 2 is to be chosen. A brick is used here as an example. A sample was taken and the following characteristic values were determined:

density: ρ = 1835 kg/m³
Thermal conductivity: λ = 0.75 W/mK
Water absorption coefficient: A_w = 0.07 kg/m²s^0.5

The material database is opened in DELPHIN. There, you can choose the category 'Building bricks' and then, by clicking on the column header, sort according to the density. As moisture transport is to be taken into account, the vapour diffusion filter restricts the selection to materials that at least have vapour transport.

A material with exactly the right data is not included. One should therefore look for similarities. Priority should be given to the Aw-value and next to the thermal conductivity. Although the density is easy to measure, it has only little influence on the calculation result.

The material with the ID 540 seems to meet the requirements best. Here it would be good to have at least one more measured parameter for moisture (μ-value, Θ_eff etc.).
Next, the material must be copied so that it can be changed. Here you have two options:

A copy into the user database is only useful if this material is needed more often outside of this project. In this case, the material is only needed for the concrete investigation. Therefore point 2 is chosen and the material is imported. For this, select the material and click on Import. Then the material reference dialog will appear:

There you click on Import into project directory to save the material in the materials directory of the project.

Afterwards the material database dialog can be closed. The material then appears in the material list of the project. A double click on the material and then a click on Edit in the reference dialog opens the material editor. Here the name should be adapted first. Furthermore, information about measurement and fitting should be entered in the comments.

You could also set the date on the right in the identification area to the current date.

Afterwards, the characteristic values must be adjusted. All three measured values are basic parameters and can be changed in the table on the top right. This can lead to side effects in the models:

First you can adjust the density. Then you should switch to the heat transport section to see the current settings. With this material only the linear model is available. Here you can easily adjust the thermal conductivity using the base parameter. The figure below shows the result.

The red arrows point to the changed data.
The next step is to switch to liquid water transport section. Here a function Kl(Θ_l) is specified as data pairs. There is also a Kl_Eff value in the basic parameters. Therefore an adjustment by means of the Aw-value is possible. The figure below shows the result.

The changes are now complete and the material can be used. A click on Check shows the current status of the material.

Since no characteristic values for vapour transport were measured in the present case, uncertainties regarding the correctness may arise. If a measurement is not possible, at least a sensitivity study should be performed. This means creating variants of the material with different μ-values and comparing the results. If these do not differ greatly, it means the vapour diffusion of this brick has little effect. Then no further considerations are necessary. If the differences are large, however, further material measurements should be made. To create variants, proceed as follows:

The name of the new material file and also the new material name should reflect the change. Then you can adjust the new material. This way you can create as many variations as you like. The figure below shows the new material list.

A top floor ceiling under an unheated attic space is to be investigated. Severe moisture damage had occurred in the ceiling. It is assumed that this damage was caused by convective moisture flow. To illustrate this, the construction is to be calculated with air flow. The following figure shows the construction with the materials and the paths of the air flow.

As can be seen in the figure, the air flow should flow from bottom to top through gaps in the wooden formwork, through the sand fill and the mineral wool into the upper air space. In order for DELPHIN to take air flow through materials into account, they must not be airtight and there must be a model for the (moisture-dependent) air permeability. For this, three materials have to be examined:

Air and mineral wool are both labelled as air permeable and have air permeability. As an example, the model for mineral wool is shown below.

The sand, on the other hand, is airtight and still needs to be adjusted. An additional task is that the air permeability for the sand should be independent of the moisture content. First, as explained in the other two examples, the material must be copied from the database into the project. Then the material editor for this material is called and the section Air transport is selected. The following display then appears.

The following can be seen:

First the flag for air tightness is switched off. Then the basic parameter list is extended so that the parameters that are not set are also visible. To do this, click on Show all parameters.

Immediately after switching off the airtightness flag, the Check button at the bottom turns red. This is the case because the material should now be able to calculate air transport, but no model exists yet. After checking Show all parameters the air permeability Kg is also shown in the basic parameter list (see picture above).
Next, a value for Kg is entered. Of course, this can only be an estimated value here, since no measurements are available. As a clue one can look at the mineral wool. There a value of 1e-4 s is entered. Since sand will certainly be denser, we choose a value of 1e-5 s. When this has been done, you should first choose Moisture dependent: linear when selecting the model. As you can see in the picture below, we now have a valid model. You can see this by the fact that the Check button is no longer red and the material is therefore valid.

The simple linear model only requires air permeability and porosity and is therefore already valid here. However, the task states that for this material the air permeability should be independent of the moisture content. This is not yet the case. For this we need the other model Moisture dependent: Spline.
When you switch to it, the model view is empty for the time being. To create the model, you have to click on Create. Then a default data set is inserted. This corresponds to the linear model (see picture below).

In contrast to the linear model, the data table is now editable. To remove the moisture dependence, only the Kg value for porosity must have the same value as for dry material. A double click on the value in the table opens the edit mode. The lower picture shows the final result.

The material can now be used. It would be conceivable here to create variants with different air permeabilities to investigate the influence of this value.