Methods to predict underwater acoustics are gaining increased significance, as the propulsion industry is required confirm noise spectrum limits, for instance in compliance with classification society rules. Propeller–ship interaction a main contributing factor emissions by vessel, demanding improved methods both hydrodynamic and high-quality prediction. Implicit large eddy simulation applying ...

The power requirement of a ship propulsion system is directly proportional to the fuel consumption and emissions released. By reducing engine power, can be reduced. One energy saving devices (ESDs) that positioned in region between stern hull propeller pre-duct. ESD improve propulsive coefficient system. This research explains effect circular pre-duct on hull-propeller interaction. A numerical ...

Marine propellers display several forms of cavitation. Of these, propeller-tip vortex cavitation is one of the important factors in propeller design. The dynamic behaviour of the tip vortex is responsible for hull vibration and noise. Thus, cavitation in the vortices trailing from tips of propeller blades has been studied extensively. Under certain circumstances cavitating vortices have been ob...

In the last years, propeller flaps have become an appealing option for coverage of a large range of defects. Besides having a more reliable vascular pedicle than traditional flap, propeller flaps allow for great freedom in design and for wide mobilization that extend the possibility of reconstructing difficult wounds with local tissues and minimal donor-site morbidity. They also allow one-stage...

Diffusion-weighted (DW) imaging is widely used in clinical imaging. To address the strong distortion encountered in EPI-based DW techniques, split-blade DW-PROPELLER [1] was proposed. With PROPELLER, when imaging a small Field of View (FOV) of a large object, No-Phase-Wrap (NPW) is usually applied to remove aliased signal in each blade before combining them [2]. However, with this conventional ...

In this study, the performance of a centrifugal pump is investigated by adding polyacrylamide (PAM) polymer over the working fluid which is tap water in this case. PAM is a long chain polymer that leads to reduce the wall shear stress and drag in a turbulent fluid. Three different blade profiles including radial, straight backward and circular backward have been examined. For this purpose, a ce...

The similarity of rotation periods of, the anomalous X-ray pulsars (AXPs), the soft gamma ray repeaters (SGRs) and the dim isolated thermal neutron stars (DTNs) suggests a common mechanism with an asymptotic spindown phase, extending through the propeller and early accretion stages. The DTNs are interpreted as sources in the propeller stage. Their luminosities arise from frictional heating in t...

Transient regimes arise when the propeller of a ship is operating in extreme seas, where ventilation and in-and-out of water effects results in loss of propeller thrust. By introducing Lyapunov based controller state reset, the performance in transient regimes may be increased without influencing the performance in calm seas. Improvements have been presented previously for dynamically positione...

A technique integrating multishot periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) and parallel imaging is presented for diffusion echo-planar imaging (EPI) at high spatial resolution. The method combines the advantages of parallel imaging to achieve accelerated sampling along the phase-encoding direction, and PROPELLER acquisition to further decrease the...

We have carried out a series of extended unbiased molecular dynamics (MD) simulations (up to 10 μs long, ∼162 μs in total) complemented by replica-exchange with the collective variable tempering (RECT) approach for several human telomeric DNA G-quadruplex (GQ) topologies with TTA propeller loops. We used different AMBER DNA force-field variants and also processed simulations by Markov State Mod...