BACKGROUND AND PURPOSE MR diagnostic of postoperative recurrent cholesteatomas is difficult. Our purpose was to compare multishot fast spin-echo periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted MR imaging (DWI) with array spatial sensitivity encoding technique (ASSET) single-shot echo-planar DWI and late postgadolinium T1-weighted MR im...

The presence of broken ice in the flow field around a propeller causes severe blade erosion, shafting, and hull vibration. This study investigates performance ship sailing polar regions under propeller–ice non-contact condition. To this end, we construct test platform for propeller-induced excitation force due to blockage large circulating water channel. hydrodynamic load propeller, cavitation ...

An unsteady RANSE code featuring dynamic overlapping grids capability is tested for the study of the flow past a rotating propeller. The propeller is considered both in open water and behind a hull. For the former case a good agreement with experimental open water curves is obtained. For the second test case preliminary results, i.e. obtained with a relatively coarse mesh, are presented that gi...

This paper presents full scale test results and discusses the effectiveness of three different highly skewed propeller designs in reducing ship “ibrati on. The test results cover three merchant ship designs, including one OBO vessel and two RO/RO vessels, having installed horsepower rangj.ng from 24,000 to 37,000 SHP. Limited discussion is presented on the relative effectiveness of installing a...

In this paper, a design of counter-rotating propeller (CRP) for stratospheric airship in low Reynolds number is tested in experiment for the first time. In consideration of stratosphere environment, a two-bladed counter-rotating propeller is designed for stratospheric airship. With the similarity theory of Reynolds number and advanced ratio, the experiment is conducted in low Reynolds number wi...

Channel wing is a propeller-coupling layout that has good low-speed performance and S/VTOL potential. Focused on the application of this at stage, paper attempts to find interaction mechanism for distributed propeller channel wing. Firstly, computation method based RANS equations propeller–wing integration was established with Momentum Source Method, which compared unsteady Sliding Mesh validat...

This research has been carried out to determine the marine propeller hydro-acoustic characteristics by Reynolds-Averaged Navier-Stokes (RANS) solver in both uniform and non-uniform wake flow at different operating conditions Wake flow can cause changes in pressure fluctuation and gas effect on propeller noise spectrum. Noise is generated by the induced trailing vortex wake and induced pressure ...

The factorization property of graviton scattering amplitudes is reviewed and shown to be valid only if the “natural” value of the gyromagnetic ratio gS = 2 is employed—independent of spin.

Abstract: An experimental study is carried out in a cavitation tunnel on a propeller operating downstream of a non-uniform wake. The goal of this work is to establish quantitative correlations between the near pressure field and the cavitation pattern that takes place on the propeller blades. The pressure field is measured at the walls of the test section and in the near wake of the propeller, ...