Iranian Classification Society Rules
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ANNEX 2 Load cases for propeller and the shape of the propeller ice torque excitation for the ships strengthened for
navigation in ice and polar class ships
Table 2.1 Load cases for open propeller
Load case | Force | Loaded area | Right handed propeller blade seen from back |
Load case 1 | Uniform pressure applied on the back of the blade(suction side) to an area from 0.6 to the tip and from the leading edge to 0.2 times the chord length | ||
Load case 2 | 50% of | Uniform pressure applied on the back of the blade(suction side) on the pro- peller tip area outside of 0.9 radius | |
Load case 3 | Uniform pressure applied on the blade face (pressure side) to an area from 0.6 to the tip and from the leading edge to 0.2 times the chord length |
| |
Load case 4 | 50% of | Uniform pressure applied on the pro- peller face (pressure side) on the pro- peller tip area outside of 0.9 radius |
|
Load case 5 | 60% of or which is greater | Uniform pressure applied on the pro- peller face (pressure side) to an area from 0.6 to the tip and from the trailing edge to 0.2 times the chord length |
Annex 2 Load Cases for Propeller and the Shape of the Propeller Ice Torque Excitation
for the Ships Strengthened for Navigation in Ice and Polar Class Ships Annex 2
Table 2.2 Load cases for ducted propeller
Load case | Force | Loaded area | Right handed propeller blade seen from back |
Load case 1 | Uniform pressure applied o the back of the blade(suction side) to an area from 0.6 to the tip and from the leading edge to 0.2 times the chord length | ||
Load case 3 | Uniform pressure applied on the blade face (pressure side) to an area from 0.6 to the tip and from the leading edge to 0.5 times the chord length |
| |
Load case 5 | 60% of or which is greater | Uniform pressure applied on the pro- peller face (pressure side) to an area from 0.6 to the tip and from the trailing edge to 0.2 times the chord length |
1,2
1
0,8
0,6
0,4
0,2
0
0 90 180 270 360 450 540 630 720
Angle of rotation [deg]
1,2
1
0,8
0,6
0,4
0,2
0
1,2 1,
2
1 1
0,8 0,
8
Ice block 2
Ice block 1
0,6
0,4
0,2
0,6
0,4
0,2
0
0 90 180 270 360 450 540 630 720
Angle of rotation [deg]
0
0 90 180 270 360 450 540 630 720
Angle of rotation [deg]
Fig 2.1 The shape of the propeller ice torque excitation for 45, 90, 135 degrees single blade impact sequences and 45 degrees double blade impact sequence(two ice pieces) on a four-blade pro- peller
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 200 400 600 800 1000 1200 1400
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 200 400 60 0 800 1000 1200 14 00
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 200 400 600 800 1000 1200 1400
Fig 2.2 The shape of the propeller ice torque excitation for 90, and 135 degree single-blade impact
sequences blades.)
and 45 degree double-blade impact sequence. (Figures apply for propellers with 4
