Appendix 2 - Friction Coefficients in Cross-flooding Arrangement
Clasification Society 2023 - Version 9.38
Statutory Documents - IMO Publications and Documents - Resolutions - Maritime Safety Committee - Resolution MSC.245(83) - Recommendation on a Standard Method for Evaluating Cross-flooding Arrangements - (Adopted on 12 October 2007) - Annex - Recommendation on a Standard Method for Evaluating Cross-flooding Arrangements - Appendix 2 - Friction Coefficients in Cross-flooding Arrangement

Appendix 2 - Friction Coefficients in Cross-flooding Arrangement

 Figure 13 Cross-flooding through a series of structural ducts with 1 manhole

k = 0.2748 Li + 0.0313 if 0 < L < 1i
k = 0.0986 Li 3 + 0.6873 Li 2 1.0212 Li + 0.7386 if 1 ≤ Li ≤ 4
k = 1.34 if Li > 4

Note: k is the friction coefficient related to each space between two adjacent girders. k is evaluated with effective cross-section area therefore in calculations use the real cross-section area A and not Sequiv. The pressure loss for entrance in the first manhole is already computed in the calculation, and k = 1 has to be added to take into account the outlet losses.

Figure 14 Cross-flooding through a series of structural ducts with 2 manholes

k = 0.4045 Li + 0.0627 if 0 < L < 1i < 1
k = 0.0424 Li 3 0.3593 Li 2 + 1.1401 Li 0.356 if 1 ≤ Li ≤ 4
k = 1.17 if Li > 4

  Note: k is the friction coefficient related to each space between two adjacent girders. k is evaluated with effective cross-section area therefore in calculations use the real cross-section area A and not Sequiv. The pressure loss for entrance in the first manhole is already computed in the calculation, and k = 1 has to be added to take into account the outlet losses.


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