systematic hull form variations to determine the best hull (Figure 2).
Using an actuator disc, the propeller action will be mimicked to estimate the propeller- hull interaction. The performance of the hull will be predicted using a systematic propeller series such as the Wageningen B-series and F-series.
Voyage simulations For a few potential hull candidates, wave added resistance calculations will be made using our Rankine source potential flow code SEACAL to determine the so-called Quadratic Transfer Functions (QTFs). RaNS calculations are also made to fine tune the SEACAL computations.
The QTFs derived will be used to run voyage simulations (including weather routing) for a weekly departure (around 500 voyages) using 10 years of weather data. From these simulations, the total required energy, fuel consumption and exhaust gas
emissions to sail at a constant speed or constant power are then derived.
Propeller optimisation For promising hull forms, a propeller is optimised for efficiency and pressure pulses using our PropArt code. For each selected hull form RANS-BEM computations are done to investigate the propeller-hull and propeller-rudder interactions. The resulting propeller efficiency and propeller-hull interaction coefficients are used to determine the propulsive power in calm water and during the voyages for the operational profile.
Maximising profit The selected hull and propeller are then used to assess the manoeuvring performance of the ship by verifying the compliance with IMO criteria. Captive CFD calculations are carried out to derive the manoeuvring coefficients of the hull. Based on the resulting mathematical model, time- domain zig-zag and turning circle
" We run voyage simulations (including weather routing) for a weekly departure (around 500 voyages) using 10 years of weather data."
simulations are performed with aNySIM and these results are verified against the IMO criteria.
All the previous steps are carried out in a loop, so the final hull is found in an iterative way, ensuring the best possible hull and propeller for the given operational profile and route, ultimately leading to the highest possible profit for the owner.
Patrick Hooijmans |
p.hooijmans@marin.nl
Figure 3: Power versus hull pressure from PropArt
Propeller design candidates
report
15
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36
