NICOP - Propeller-Hull Interaction in Waves
Abstract
Objective The objective of this NICOP project is to understand the detailed phenomena of the propeller load fluctuation in waves for a high Froude number displacement ship. Ship resistance and propulsion tests in waves will be conducted by experiments and computations. Development of a model for the relationship between incident waves and propeller load fluctuations based on computational and experimental results is also a target. The model can be used to design a more efficient propulsion system for a ship in waves. Tasks Experiment – Prof. Yasuyuki Toda The experiment will be conducted in the towing tank of Osaka University. (a) Build ship and propeller model Duration: 12 months (first year); Cost: $32,000 USD The 3m long KCS ship model and propeller models with a diameter of 10.3 cm (right- and left-handed) will be built by Kobe Sanshin Seisakusho Co., LTD. The models will be manufactured and inspected under strict tolerance. It will take almost the whole first fiscal year. (b) Resistance and self-propulsion test in calm water and head waves Duration: 12 months (second year); Cost: $3,600 USD Resistance and self-propulsion tests will be conducted in the Osaka University towing tank after the models are delivered from Task (a). Depend on the towing tank schedule, the measurement of forces and moments will be conducted several times a year. Each time may take several weeks. The test conditions: Froude number Fr=0.26 corresponds to 1.41 m/s in the towing tank. Reynolds number Re is 4.23×106 based on 3m long model (Re may slightly change due to the water temperature). For the resistance test, a wider range of wave conditions will be considered: clam water and ?/L=0.6~2.0 (?: wave length; L: ship length). Generally, the maximum added resistance was found around ?/L~1 but the exact ?/L varies due to ship geometry. For self-propulsion tests, the model points (the propeller rotating speed in model scale) will be found for four wave lengths: ?/L<1, ?/L~1, ?/L>1 and calm water. (c) S-PIV measurements in calm water and head waves Duration: 24 months (second – third year); Cost: $26,800 USD The flow field around the propeller plane for several stations will be measured by LaVision S-PIV system at the model points obtained in Task (b) for four wave lengths: ?/L<1, ?/L~1, ?/L>1 and calm water. Up to the shared usage of the towing tank in the department, S-PIV measurements will be conducted several times a year. Each time including the data post-process may take months. (d) New phase synchronization circuit and S-PIV measurement Duration: 36 months (first – third year); Cost: $28,800 USD (second – third year) To synchronize the measurement with the propeller rotational speed and wave encounter frequency, a new circuit will be designed from the start of this project. It may take three years from prototype design to conducting preliminary measurement along with the S- PIV system. For each carriage run, only one blade position could be specified. Thus, for one wave length only one blade position will be chosen between 0 and 72 degree for a five-bladed propeller, e.g. propeller tip pointing up (0 degree) at ship bow-up position. Computations – Dr. Ping-Chen Wu The computation will be performed on the cluster machine in Osaka University.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 03, 2016
- Source ID
- N629091612015
Entities
People
- Yasuyuki Toda
Organizations
- Office of Naval Research
- Osaka University
- United States Navy