Theory
Glass and rock wools of the same bulk density differ in fibre diameter, so their flow resistivities differ. The program uses a separate power law fitted to the measurements of each material in Komatsu (2008) (Table 3: 15 glass wools, 9 rock wools). At 30 kg/m³ the glass-wool fit gives about 1.2×10⁴ Pa·s/m² and the rock-wool fit about 1.1×10⁴; at 90 kg/m³, about 5.6×10⁴ and 6.2×10⁴.
Equations
(1)
| where | meaning | unit |
|---|---|---|
| Estimated flow resistivity | Pa·s/m² | |
| Bulk density | kg/m³ |
Default and rule
- Default
- glass wool
- Rule
Glass wool.
- Source
Power-law fits by the program to the measurements in Table 3 of Komatsu (2008).
Valid range glass wool | rock wool
Other materials
Only glass and rock wool are covered. For steel wool, ceramic fibre or foams, enter a measured flow resistivity instead.