A new propeller EPI pulse sequence with reduced sensitivity to field inhomogeneities is proposed. Image artifacts such as blurring due to Nyquist ghosting and susceptibility gradients are investigated and compared with those obtained in previous propeller EPI studies. The proposed propeller EPI sequence uses a readout that is played out along the short axis of the propeller blade, orthogonal to...

The physically correct capture of propeller-rudder interaction is important if ship self-propulsion parameters are to be accurately predicted. Full resolution of a time accurate computational fluid dynamics calculation based on the Reynolds Averaged Navier Stokes equations requires a significant computational resource. The axial and tangential accelerations generated in the flow by the passage ...

However, a solution does exist, whose understanding relies on the application of the classical laws of physics and which is free of contradictions: if the electron is assumed to be made up of two massless constituent particles, then this assumption correctly predicts the experimental results. It provides the correct relationship between the parameters of the electron: its mass, its constant ang...

This paper focuses on strong propeller effects in a full six degree-of-freedom (6DOF) aerodynamic modeling of small UAVs at high angles of attack and high sideslip in maneuvers performed using large control surfaces at large deflections for aircraft with high thrust-to-weight ratios. For such configurations, the flight dynamics can be dominated by relatively large propeller forces and strong pr...

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...

OBJECTIVE The objective of this study was to evaluate the feasibility of using multishot PROPELLER for diffusion-weighted imaging (DWI) of the abdomen. MATERIALS AND METHODS Diffusion-weighted abdominal imaging was performed in 9 healthy volunteers and 3 patients using both single-shot DW-SE-EPI and multishot DW-PROPELLER (BLADE sequence). We compared ADC measurements in phantoms, liver and p...

Propeller crashback is an off-design operating condition where a propeller rotates in the reverse direction. Experiments (Bridges 2004, Tech Rep. MSSU-ASE-04-1, Department of Aerospace Engineering, Mississippi State University) have shown that the presence of an upstream hull significantly increases the side force on a propeller in crashback below an advance ratio of J = −0.7. Large-eddy simula...

Abstract An alternative twin rudder system known as the Gate Rudder© has been applied to newbuild vessels and an existing ship with aim improve their hydrodynamic performance reduce greenhouse gas emissions. The consists of two asymmetric cross-sections L-shaped blades located either side a propeller. generate thrust (duct effect) from propeller ship-included flow. Initially, forces moments sin...

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...