Numéro : 1899 - Year : 1982
Ship-model correlation -application of the ITTC 1978 method to two 122000 m3 LNG
M. JOURDAIN, Directeur Général de l’Institut de Recherches de la Construction Navale ( IRCN )
J. J. MUNTJEWERF, Vice- Président du Bassin de Wageningen ( MARIN )
Following a short introduction on the history of ship-model correlation methods for propulsive performance, the paper pays specially attention to the particularities of the ITTC 1978 method at present being recommended by the International Towing Tank Conference.
The paper explains in detail the application of this method in the calculation of trials predictions from model tests carried out in the NSMB depressurised towing tank, while it also shows the results obtained on trials with two identical ships, from which one was tested at two load conditions. These trials results have been slightly corrected to reduce them to ideal weather conditions corresponding to those assumed for the predictions, i.e. zero wind, no waves.
The thus corrected trials results are compared with the predictions and the differences are analyzed in detail , not only with respect to overall values of power and resolutions but also for the derivatives wake and thrust.
The agreement is very satisfactory and reconfirms the interest of the ITTC 1978 method for this particular case, which seems to be rather unfavourable because of its unusual variations of resistance as a function of speed.
Advanced search
Year