The Screw Propeller

The Automatic Design of the Screw Propeller in Non-Axial Flow

Computational Analysis of Propeller Sheet Cavitation and Propeller-ship Interaction

This paper describes a computational procedure which is being developed for the practical analysis of propeller sheet cavitation and propeller-ship interaction including hull pressure fluctuations. The computational procedure consists of three different, coupled methods: (i) a RANS method for the analysis of the viscous flow around the ship hull and the determination of the velocity field in th...

Computer Aided Geometric Modeling and 5-axis Milling of a Screw Propeller in a Single Setup: a Case Study

This paper presents a geometric modeling method and 5-axis CNC machining algorithm for the manufacture of screw propellers in one single setup. A novel approach for 5-axis roughing is developed and implemented in addition to further streamline finishing sequences. The toolpath is generated by dividing the propeller model into milling regions viz. the front & rear blade faces, the leading & trai...

Trans-sonic Propeller Stage

We follow the approach used by Davies and Pringle (1981) and discuss the trans-sonic substage of the propeller regime. This substage is intermediate between the supersonic and subsonic propeller substages. In the trans-sonic regime an envelope around a magnetosphere of a neutron star passes through a kind of a reorganization process. The envelope in this regime consists of two parts. In the bot...

Quiet PROPELLER MRI techniques match the quality of conventional PROPELLER brain imaging techniques.

BACKGROUND AND PURPOSE Switching of magnetic field gradients is the primary source of acoustic noise in MR imaging. Sound pressure levels can run as high as 120 dB, capable of producing physical discomfort and at least temporary hearing loss, mandating hearing protection. New technology has made quieter techniques feasible, which range from as low as 80 dB to nearly silent. The purpose of this ...