Case 4.1: KCS shallow water, forces & moments
CASE 4.1 (case 4.1.1 and 4.1.2)
1.1 Description of case
- KCS hull shape
- Fixed in surge, sway, roll and yaw. Upright condition (Ø=0). The experimental results are obtained free to trim and sink
- Calm water
- Water depth to draught ratio 1.2 (i.e. 20% under keel clearance when the ship is at rest)
- LPP = 7.2785 m (scale 31.6)
- Vmodel=0.8007 m/s, Fn = 0.09476 (corresponding to full scale 8.75 knots) (Case 4.1.1 and 4.1.2 package 1)
- Vmodel=0.5338 m/s, Fn = 0.06317 (corresponding to full scale 5.83 knots) (Case 4.1.2 package 2 and 3)
- g = 9.81 [m/s2], ρ=1000 [kg/m3]; ν=1.05×10-6 [m2/s]
- Propeller present. The propeller should work at the propeller point so that there is model self-propulsion at Vmodel=0.8007 m/s, Fn = 0.09476 (corresponding to full scale 8.75 knots), in shallow water at zero drift and zero yaw rate (and rudder).
Second speed condition is propeller overloading condition, that means; V_model=0.5338 m/s with the propeller working at the self-propulsion RPM of V_model=0.8007 m/s.
- All tests were performed with stock propeller at KRISO, which shows equivalent performance to the propeller 'KP505' released on this website.
Its open water characteristics are uploaded as 'KCS Propeller Openwater Data (KRISO)'.
- Rudder present, but at zero rudder angle (exactly zero).
1.2 Requested computations
The requested info comes in 2 cases.
- You can only submit case 4.1.2 package 1 when you delivered case 4.1.1
- You can only deliver case 4.1.2 package 2 when you deliver case 4.1.2 package 1.
- You can only deliver case 4.1.2 package 3 when you deliver case 4.1.2 package 2.
Forces and moments should be supplied as follows:
- The N-moment (moment around the z-axis) should be supplied w.r.t. the mid-ship.
- Only the hydrodynamic forces are to be supplied: the inertial forces are not to be included.
- Forces and moments are to be given non-dimensional:
| Package |
Drift angle
(β=-atan(v/u) |
Non-dimensional rate of turn r’ |
Requested quantities |
| Case 4.1.1 |
15° |
0 |
X’, Y’, N’ |
| 10° |
0 |
X’, Y’, N’ |
| 6° |
0 |
X’, Y’, N’ |
| 4° |
0 |
X’, Y’, N’ |
| 2° |
0 |
X’, Y’, N’ |
| 0° |
0 |
X’, Y’, N’ |
| -2° |
0 |
X’, Y’, N’ |
| -4° |
0 |
X’, Y’, N’ |
| Case 4.1.2, package 1 |
0° |
0.3 |
X’, Y’, N’ |
| 0° |
0.35 |
X’, Y’, N’ |
| 0° |
0.4 |
X’, Y’, N’ |
| Case 4.1.2, package 2 |
4° |
0.3 |
X’, Y’, N’ |
| 4° |
0.35 |
X’, Y’, N’ |
| 4° |
0.4 |
X’, Y’, N’ |
| Case 4.1.2, package 3 |
8° |
0.3 |
X’, Y’, N’ |
| 8° |
0.35 |
X’, Y’, N’ |
| 8° |
0.4 |
X’, Y’, N’ |
1.4 Format
Link to an excel file, which a submitter can download.
The yellow fields in the excel sheet should be filled in. The excel sheet should be send to the organizing committee per email address “
simman2019host@gmail.com”.
1.5 Example
For KCS shallow water, we elaborated an actual example of an actual submission compared to actual experimental data.
Table below gives an example of the data that we would be getting for the KCS
for case 4.1.1 and 4.1.2.. Submitters should generate an excel sheet in the format of the Table
below. The submitter has to type the calculated X’, Y’ and N’.
Table: Data from “submission 1”, (this is an actual case, where an empirical method is used to generate the forces and moments).
The organizers will compare the submitted results to experimental data. Comparing the above submission (above table) to experimental data will give the below 2 sets of figures. It is the intention to have many submissions in the same type of figure to learn about the prediction capabilities for which combinations of r’ and β.
Comparison of submission 1 to the experimental data for KCS in shallow water for pure drift (case 4.1.1)
Comparison of submission 1 to the experimental data for KCS in shallow water for pure yaw and yaw and drift (case 4.1.2)
