Research Article
Study on Leakage Model of Typical Penetration of Closed Structures Based on Porous Media Seepage Theory
Table 3
Fitting of calculation formula for leakage rate of manhole pressure cover.
| Initial sealing conditions F/kN | 100 |
| Circumference of seal ring, B/m | 3.216 |
| Surface composite roughness, σ/m | 3.2 × 10−6 |
| Rubber material hardness, HA | 60 |
| Kinematic viscosity of medium, μ/(Pa.s) | Pressure P/MPa | 0.45 | 1 | 1.5 | 2 | Dry air | 1.80 × 10−5 | 1.80 × 10−5 | 1.80 × 10−5 | 1.80 × 10−5 | Saturated steam | 8.00 × 10−5 | 5.90 × 10−5 | 5.30 × 10−5 | 4.69 × 10−5 | Contact width, L/m | 0.023 |
| Permeability, K | Rough flow factor, Φσ | Φσ = exp (−0.9242 + 0.7026). | Height flow factor, Φh | Φh = exp (0.7545 − 3.673). | Dimensionless gap height, | . | Dimensionless mean contact stress, | . | Permeability, K | K = ΦσΦh()3(h0)2/12. |
| The formula of leakage rate | . |
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