Dimension of the considered cross-flooding pipe:
Diameter
|
D = 0.39 m
|
Length
|
l = 21.0 m
|
Cross-section area
|
S = 0.12 m2
|
Wall thickness
|
t = 17.5 mm
|
k-values for the considered cross-flooding system:
Inlet
|
0.45
|
Pipe friction
|
1.08
|
2 radius bends (α = 45°)
|
0.36
|
Non-return valve
|
0.50
|
Sufficient air venting is assumed to be in place.
Time required from commencement of cross flooding θ
0 to the final equilibrium condition θf
:
Head of water before commencement of cross-flooding:
Volume of water which is used to bring the ship from commencement
of cross-flooding to the final equilibrium condition:
Final head of water after cross-flooding:
Calculation of any transient situation of cross-flooding:
The purpose is to find the situation after 600s.
Assumed transient situation:
Volume of water which is used to bring the vessel from the
transient situation to the final equilibrium : Wθ =
365 m3 – 265 m3 = 100 m3
Time required to bring the vessel from any transient situation
to the final equilibrium condition:
Time between commencement of cross-flooding and assumed
transient situation:
T = Tf – Tθ = 721 s –
240 s = 481 s
As T is less than 600 s, further transient
situations with larger cross-flooded volume may be calculated in the
same way.
On the reverse, if T was of more than 600 s,
further transient situation with smaller cross-flooded volume may
be calculated.
Situation after 600 s may be found by successive iterations.