| Guided by her enterprise's spirit "to untie,strive,pioneer and be enterprising",Hudong-Zhonghua Shipbuilding (Group) Co.,Ltd. has been achieving great success in the world shipbuilding market. Since ten years ago,it has become a central task for Hudong -Zhonghua to keep on applying advanced shipbuilding technology and upgrading the ship products structure in order to have an advantage in the severe competition in the international shipbuilding market. Concentrating her efforts on the central task,Hudong-Zhonghua has produced her well-known brand of China HD Type ships by having developed many new types of ships in series of bulk carriers,oil tankers and container vessels. These self-developed ships have made her acquired a large number of shipbuilding orders which have come out with remarkable social and economic benefits. One of her policies to enhance China HD Type ships to be more competitive in the market is,among many others,to carry out a comprehensive research for power saving as per the form of the ships. A high-efficiency propeller technology is one of most important researches we have conducted.HD propellers are a type of marine propellers having new blade sections,moderate skew and a small area-ratio,with the virtues of higher efficiency,lower vibration and noise and lighter weight.Based on the theory of potential flow,steady lifting-surface theory and the potential based low-order surface panel methodi the mathematical models for predicting the performance of the HD propeller and MAU propeller are respectively established in this paper,and the numerical calculations are alsocarried out. In lifting-surface theory,the non-liner phenomena of the trailing vortex in the transition wake area and of the tip vortex separation are considered. In surface panel method hyperboloidal quadrilateral panels are employed and the Morino's analytical formulation is used to determine the influence coefficients. The more reasonable pressure Kutta condition is satisfied at the trailing edge of propeller blade. Comparisons made among the calculated data of above two methods for open-water performance of the HD propeller and the test results shown that surface panel method is in good agreement with test results. Comparisons also made among the calculated data of above two methods for the pressure distribution on blade section of the HD propeller and MAU propeller,the results shown that the pressure distribution of the HD propeller is much uniform than the those of MAU propeller. So that the surface panel method for predicting the performance of the HD propeller presented in this paper is effective for engineering practice.The experimental researches are carried out for the improvement of the shape of HD type's 70,000 Deadweight Panamax Oil tanker,performance of HD propeller and the cooperation among the hull,main engine and propeller. The researches include following experiments:1) Vessel's resistance test at the conditions of ballasting,full loading and over loading,ship's models are selected based on the testing result.2) Wake measurement on shafting direction,at over loading condition.3) Open-water and self-propulsion tests for the HD propeller and MAU propeller.4) Cavitation observation and pulsing pressure measurement.5) Sea trial of the actual vessel.As a result,the effect of power-saving for the HD type's 70,000 DeadweightPanamax Oil thaker is much higher,the performance of HD propeller is better than MAU propeller and the cooperation among the hull,main engine and propeller is better too. By means of the sea trial,it is verified that at full loading condition of 12.5m draught,the vessel's speed attained to 15.09 knots with the rotate speed of 100.5rpm,at the condition of the sea margin of 15% and rotate speed margin of 5% at CSR of main engine.By surface panel method,the open-water performances of the HD actual propellers having different area-ratio and pitch ratio are predicted. The KT,KQ-J curves are drown and diagrams are developed as HD4-40,4-45,4-55 which be av...
|
PDF Full Text Request