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Full-Text Articles in Engineering
Nonlinear Dynamic Analysis Of An Orthotropic Composite Rotor Blade, Ming-Hung Hsu
Nonlinear Dynamic Analysis Of An Orthotropic Composite Rotor Blade, Ming-Hung Hsu
Journal of Marine Science and Technology
This work presents the nonlinear dynamic analysis of orthotropic composite rotor blade using differential quadrature method (DQM). It can be found that the same efficient and procedure of DQM for both uniform composite beam and pre-twisted non-uniform composite beam. In this approach, only nine sample points are needed to achieve convergence. Dynamic responses of orthotropic composite rotor blade with various rotor rotation speeds are determined. Both linear and nonlinear dynamic responses have been obtained in order to study the significance of the nonlinear effect. The transient responses of the derived systems are calculated by using Newmark method. The bending-torsion coupled …
Single And Multiple Surface Scatterings From Rough Surfaces, Chin-Yuan Hsieh, Shun-Hsyung Chang
Single And Multiple Surface Scatterings From Rough Surfaces, Chin-Yuan Hsieh, Shun-Hsyung Chang
Journal of Marine Science and Technology
The objective of this paper is to study the contributions of multiple scattering and compare it with those of the single scattering from randomly rough surfaces. The existing Kirchhoff, small perturbation and IEM scattering model cannot be used to predict the multiple scattering along the azimuth angle. In this paper we modify the IEM model by adding the phase terms in Green’s function and its derivative for multiple scattering. The function of phase term is significant to investigate the contribution of multiple scattering in the upward and downward directions. The contribution by multiple scattering is mainly based on the normalized …
Lump Circuit Modeling And Matching Consideration On Acoustical Transmitters For Underwater Application, Yeong-Chin Chen, Sean Wu, Cheng-Che Tsai
Lump Circuit Modeling And Matching Consideration On Acoustical Transmitters For Underwater Application, Yeong-Chin Chen, Sean Wu, Cheng-Che Tsai
Journal of Marine Science and Technology
In underwater environment the acoustical wave can transmit a long ranges away from the transmitter than the electromagnetic wave does. So far, the piezoelectric ceramic is still the best candidate as acoustical telemetry transmitters in underwater applications. The impedance matching on the interface between electro-acoustical transducer and electrical transmitter has been the most important subject to confirm the high transmitting efficiency. In this research, a lumped equivalent circuit of electro-acoustic transducer is proposed. Then, the network theorem is implemented to design a high power transformer for impedance matching, and to improve the electro-acoustic efficiency of the transducer. In the developing …
Discontinuous Conduction Mode Of Negative Output Elementary Circuit, Jung-Chien Li, Han-Yang Chen
Discontinuous Conduction Mode Of Negative Output Elementary Circuit, Jung-Chien Li, Han-Yang Chen
Journal of Marine Science and Technology
The negative output elementary circuit operated in the discontinuous conduction mode is discussed. The voltage transfer gain of this dc-to-dc converter depends on switching frequency, conduction duty ratio, inductance, and load resistance. The condition for the discontinuous conduction mode is derived and verified. The variation ratio of the output voltage is also derived.
Optimal Pitch, Speed And Fuel Control At Sea, Thomas Hellström
Optimal Pitch, Speed And Fuel Control At Sea, Thomas Hellström
Journal of Marine Science and Technology
This paper discusses algorithms for fuel saving control for large vessels. The fuel saving is achieved by optimizing control at three levels: low level propeller and main engine control, dynamic speed control to avoid peeks in the fuel consumption and finally route planning for optimal speed profiles compensated for varying depth and weather conditions. The control problems involve classical control functions as well as numerical optimization.
Response To Comments On "A Novel Approach To Determine The Astronomical Vessel Position", Jiang-Ren Chang, Chih-Li Chen, Tien-Pen Hsu
Response To Comments On "A Novel Approach To Determine The Astronomical Vessel Position", Jiang-Ren Chang, Chih-Li Chen, Tien-Pen Hsu
Journal of Marine Science and Technology
No abstract provided.