Development of Reaction Fin as a Device for Improvement of Propulsive Performance of High Block Coefficient Ships

Abstract

Reaction fin is a device for improving propulsive performance of ships by providing preswirl to the propeller inflow for cancellation of rotation in the slipstream. This report describes the development of reaction fin for high block coefficient ships undertaken in Mitsubishi Heavy Industries, Ltd. First, explanations are given on the effectiveness of reaction fin for full ships with some results from basic researches carried out in the early stage. Next, development made on its practical application is described which includes studies on various aspects such as structure, vibration, monouevrability etc. as well as propulsive performance. Finally, full-scale results are introduced from the results of the two ships fitted. with a reaction fin, showing that it is as effective as expected for improving propulsive performance without causing any troubles for service.

Development of Reaction Fin as a Device for Improvement of Propulsive Performance of High Block Coefficient Ships

“…After the publication of ref. [3] influence of a rudder on the effectiveness of reaction fin was examined on the ship model III, and it was shown that the effectiveness of reaction fin is little affected by existence of a rudder behind the propeller.…”

Validation of Optimally Designed Stator-Propeller System by Efd and CFD

“…A pre-swirl stator was symmetric and has six blades, as shown in Fig. 2 [11]. Blades at the top and bottom positions appear to be missing; this is intended in consideration of the blockage effects against the on-coming flow and potential-flow docking problems, respectively.…”

Theoretical Calculation of Propulsive Performances of Stator-Propeller in Uniform Flow by Vortex Lattice Method

“…The resultant velocity V, at the i-th control point is composed of the summation of all induced velocities of the vortex lattices of the propeller, the stator and the duct of stator, and undisturbed inflow velocity, namely, Since we replace the continuous source distribution by some discrete line sources, the strength of the discrete line source representing the chordwise element between sn and sn+i is given by the formula : ( 6 ) where s is the chordwise coordinate measured from the leading edge, …”