Hello,
We use the rules RT2005 TH-U - Fascicule 2 (France) to determine some materials properties.
We find two values of the density :
- dry density
- nominal density
We supposed that the bulk density is a dry density and the nominal density is the density with the typical built-in moisture.
Are we right ?
Thanking you by advance.
Greetings.
Bulk density
Re: Bulk density
Hi Raymond,
I can not comment on the meaning of those terms in the context of the rules you cite, but in WUFI the bulk density should be the dry density.
In WUFI, the bulk density of a material is used to convert the mass-specific heat capacity (J / kg K) specified by the material data to the volume-specific heat capacity (J / m³ K) needed by the transport equations.
These heat capacities are assumed to be those of the dry material, because WUFI automatically adds the contribution of any water contained in the material to obtain the heat capacity of the wet material. So for consistency, the heat capacity as well as the bulk density specified in the material data should both refer to the dry material.
On the other hand, the difference will usually not be very important, considering the measurement uncertainties inherent in both the heat capacity and the bulk density, or taking into account possible variations in the production of the materials, even if you could measure the material data of some individual specimen with high precision.
Many of the heat capacities given in the material database are only estimates anyway, and there would be little point in spending much effort to determine highly precise bulk densities in these cases.
Kind regards,
Thomas
I can not comment on the meaning of those terms in the context of the rules you cite, but in WUFI the bulk density should be the dry density.
In WUFI, the bulk density of a material is used to convert the mass-specific heat capacity (J / kg K) specified by the material data to the volume-specific heat capacity (J / m³ K) needed by the transport equations.
These heat capacities are assumed to be those of the dry material, because WUFI automatically adds the contribution of any water contained in the material to obtain the heat capacity of the wet material. So for consistency, the heat capacity as well as the bulk density specified in the material data should both refer to the dry material.
On the other hand, the difference will usually not be very important, considering the measurement uncertainties inherent in both the heat capacity and the bulk density, or taking into account possible variations in the production of the materials, even if you could measure the material data of some individual specimen with high precision.
Many of the heat capacities given in the material database are only estimates anyway, and there would be little point in spending much effort to determine highly precise bulk densities in these cases.
Kind regards,
Thomas