Ship operators are calling more often for reduced fuel consumption and economic ship operation also in offdesign. The versatile operation profile of ship types such as RoRo-vessels are then a challenge for the design of the propeller and for the propulsion concept. This paper presents aspects on the propeller design and propulsion concept of a ship as well as design methods for the propeller. L...

Introduction Diffusion-weighted MRI (DWI) provides a non-invasive method for in vivo evaluation of tissue water mobility. Most DWI studies employ single-shot DWEPI techniques which can suffer severe artifacts and image distortion in abdominal imaging applications. Multi-shot TSE-based DW-PROPELLER [1] may overcome these limitations. DW-PROPELLER for brain [2] and abdominal [3] imaging has demon...

Today’s unmanned aerial vehicles are being utilized by numerous groups around the world for various missions. Most of the smaller vehicles that have been developed use commercially-off-the-shelf parts, and little information about the performance characteristics of the propulsion systems is available in the archival literature. In light of this, the aim of the present research was to determine ...

Suday, Sptem er 5, 2016 significantly increases the risk of postoperative vaginal stenosis. This paper proposes a simple technique for the reconstruction of thin septa, utilising two interdigitating Y-flaps. The authors also present their 7-year experience of utilising this technique. Custom made illustrations and serial intraoperative photographs will accompany the podium presentation in order...

This paper proposes a thrust estimation scheme for marine propellers in four-quadrant operations. To calculate the thrust and torque coefficients of screw propeller in four-quadrant, a Chebyshev fit expression of the propeller properties in four-quadrant for surface vessel is given, and then it is changed into an ordinary polynomial expression. These expressions are suitable for calculating the...

this paper describes a contra-rotating propeller (crp) system to calculate the hydrodynamic characteristics and then design the optimum operational condition to be installed on two different large bulk carriers and vlcc. the method is based on boundary element method (bem) to obtain the hydrodynamic performance of any complicated configuration such as crp system, and then the optimum propeller ...

This paper investigates the influence of the propeller on the drag of twin self-propelled AUVs, firstly, to examine the fleet performance for various propulsive conditions of leading and following AUV and, secondly, to study the parametric influence of transverse separations and longitudinal offsets on the fleet’s drag. A series of CFD RANS-SST simulations have been performed at the Reynolds Nu...

This study presents the results of cavitation tunnel tests carried out with model propeller of a Fisheries Research Vessel (FRV) and those of noise measurements with its full-scale propeller to validate the low-noise performance of this propeller. The tests involve the simulation of a target wake using a wake screen and the determination of the nature and extent of the observed cavitation behin...

Contra-rotating propellers have renewed interest from the naval architecture community, because of the recent development of electric propulsion drives and podded propulsors. Contrarotating propulsion systems have the hydrodynamic advantages of recovering part of the slipstream rotational energy which would otherwise be lost utilizing a conventional screw propeller system. The application of th...

An experimental dataset is presented of propeller performance in static condition and at low subsonic airspeeds for various angles attack up to 90 deg. Numerical investigation through a Reynolds-averaged Navier–Stokes computational fluid dynamics model revealed the mechanisms behind changes with advance ratio, angle attack, configuration changes. The was found be free major errors very suitable...