نتایج جستجو برای: propeller
تعداد نتایج: 3766 فیلتر نتایج به سال:
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...
High spin levels in 'Nb and 'Zr have been studied with the reactions Sr{GI,i, 3n) ~ Nb and 8 Sr(GLi, P2n) 'Zr by pulsed-beam-p, p-p, and p-W(&) measurements. Isomers were found which agree with theoretical predictions: a v =5.42 + 0.18-p, sec state at 2035 keV in Nb, l(g&g2) pqg2, $ ), and a v=6.15+0.50-psec state at (8188) keV in 'Zr, [(g9~2) &&d5y2, ~~+). The ~+9y2P, y2d&y2, + ) state in ~'Zr...
Hydrodynamic analysis of the marine propulsors with complex geometry such as podded drive systems, ducted propellers, and waterjet systems are more complicated than conventional propeller systems. This fact has caused the usage and development of numerical methods and techniques. The hybrid method to couple the Blade Element Momentum Theory (BEMT) with Reynolds-Averaged Navier Stokes method (RA...
BACKGROUND Henan Province has been in the malaria elimination stage, with all reports of the disease being imported since 2012 and over 90% coming from Africa. Surveillance and population studies are essential for the early detection and subsequent prevention of the spread of drug resistance. The K13-propeller gene was recently identified as a proposed molecular marker of artemisinin (ART) resi...
PURPOSE Hippocampal sclerosis (HS) is the most common cause of refractory temporal lobe epilepsy. Histopathologically, HS is characterized by neuron loss and gliosis. HS can be identified on MRI by signal increase on T(2)-weighted images and volume loss on T(1)-weighted volume images. The Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction ("PROPELLER") sequence has exc...
Mutations in the Plasmodium falciparum K13-propeller domain have recently been shown to be important determinants of artemisinin resistance in Southeast Asia. This study investigated the prevalence of K13-propeller polymorphisms across sub-Saharan Africa. A total of 1212 P. falciparum samples collected from 12 countries were sequenced. None of the K13-propeller mutations previously reported in ...
We propose a four-quadrant propeller model suitable for energy-efficient motion planning of autonomous marine vehicles. The model can be used to capture the main features of experimental thrust and torque curves by using a small number of parameters. We explore the connection between the propeller thrust, torque, and efficiency curves and the lift and drag curves of the propeller blades. The mo...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید