MODEL SCALE INVESTIGATIONS OF VARIOUS PROPULSIVE ARRANGEMENTS FOR LARGE TANKERS AND BULK-CARRIERS

The investigations started with a series of model tests with both a twin-screw and a single-screw model. Towrope tests, wake measurements, propulsive tests with stock propellers with several arrangements of rudders and propellers were performed. All these tests were partly carried out in order to have as good a foundation as possible when designing suitable propellers and nozzles for the models to be tested. The propeller and nozzle designs achieved in this way were then adopted for a series of tests conducted as it appears below: 1. The twin-screw model with 6-bladed propellers and one center-rudder. 2. The single-screw model with a 6-bladed propeller. 3. The single-screw model with a 4-bladed propeller in a nozzle with length/diameter-ratio = 0.5. 4. "Backing" tests in loaded condition with reversed propellers, to have crash-stop curves, with: a. The single-screw model with and without nozzle and design rpm = 80. b. The twin-screw model with 80 rpm-propellers. 5. Single-screw model with nozzle with two different length/diameter-ratios L/D = 0.5 and 0.68, each partly with three different longitudinal positions and four tilting angles of nozzle-axis in relation to the propeller axis. Most of these tests were carried out both in loaded and in ballasted conditions. 6. Cavitation tests in behind condition for the single-screw model with and without nozzle, both for 80- and 110 rpm-propellers. 7. Open water tests for all the propellers and for the propellers in nozzles with length/diameter-ratio L/D = 0.5. (Open water tests with propeller in nozzle did not yield reasonable results).

• Corporate Authors:

  Ship Research Institute of Norway

  P.O. Box 4125, Valentinlyst, Hakon Hakonsongt. 34
  N-7001 Trondheim,   Norway 
• Authors:
  • Ottesen, E K
• Publication Date: 1973-8

Media Info

• Features: References;
• Pagination: 36 p.

Subject/Index Terms

• TRT Terms: Backing (Driving); Cavitation (Mechanics); Driving; Maneuvering; Nozzles; Propellers; Propulsion; Screw propellers; Tests; Towing devices; Vehicle design; Very large crude carriers; Wakes
• Old TRIS Terms: Model testing; Propeller design; Propulsion tests; Towing tests; Twin screws; Wake measurement
• Subject Areas: Design; Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00167713
• Record Type: Publication
• Source Agency: Ship Research Institute of Norway
• Report/Paper Numbers: R-24.73
• Files: TRIS
• Created Date: Dec 27 1977 12:00AM