Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Entire DC Network
Study On Mechanical Properties Of A356 Alloys Enhanced With Preformed Thixotropic Structure, Shueiwan H. Juang, Shyh-Ming Wu
Study On Mechanical Properties Of A356 Alloys Enhanced With Preformed Thixotropic Structure, Shueiwan H. Juang, Shyh-Ming Wu
Journal of Marine Science and Technology
A preformed A356 alloys with thixotropic structure (designated SSM-A356) was systematically studied on mechanical properties in order to establish the database for further investigations in forming and heat treatment. Because of the specific microstructure and characteristics, the heat treatment conditions of SSM-A356 were explored through the observations of microstructure and the measurement of micro-hardness. In the investigation of heat treatment, it was observed that the eutectic silicon was refined and spheroidized which is unlikely for conventional processing. The mechanical testing results showed that the yield and ultimate tensile strength of SSM-A356 were respectively around 115% and 34% greater than those …
Variable-Thickness Boundary Layers For Sliding Mode Control, Chyun-Chau Fuh
Variable-Thickness Boundary Layers For Sliding Mode Control, Chyun-Chau Fuh
Journal of Marine Science and Technology
Sliding mode control is a nonlinear feedback control technique which provides good robustness against modeling uncertainties and external disturbances. However, as the uncertainties or disturbances increase, a greater control input is required, and the control signal may cause an undesirable chattering phenomenon. In general, the further the system trajectory from the origin, the more violent the chattering effect. However, as the trajectory moves closer to the origin, the degree of chattering gradually reduces. As a result, even if an attempt is made to eliminate chattering by introducing a small constant boundary layer around the sliding surface, the chattering phenomenon may …
Characteristic Study Of Mhd Minipump, Je -Ee Ho
Characteristic Study Of Mhd Minipump, Je -Ee Ho
Journal of Marine Science and Technology
The present study aims to develop and discuss the availability of the Magneto Hydrodynamics Minipump (MHD) as a miniaturizative part specified for precise manufacturing or medical application. Based on the MHD theory, an available working current (1.8A) induced by lower voltage (0-12V) and weaker magnetic intensity (0.04T) meets the need in mini-system operation. However, precise estimations of working capacity, maximum head, dynamic head, and static head in various electrolyte concentrations are necessary. Furthermore, this work also provides a simplified analytic model with a static balance between Lorentz force, surface tension force, and body force. Compared with analytic solutions and experimental …
Developing A Convective Code With Vorticity Transport In Upwind Method, Je -Ee Ho
Developing A Convective Code With Vorticity Transport In Upwind Method, Je -Ee Ho
Journal of Marine Science and Technology
The Navier-Strokes equations are usually used to solve the convective problems, however, to satisfy the conversation of mass, the uncertainty of pressure terms will easily trigger off the numerical divergence during the iterative process; which results in a calculating failure and makes the numerical solutions impossible. In this study, a vorticity–transport method that avoids the involvement of pressure terms by cross differentiate the governing equations and meets the flow conservation with stream function was proposed. With the aid of the upwind scheme and implicit method, an effective transformation from the partial differential equations into the vortex potential algebraic equations would …
Investigation On The Blast Resistance Of A Stiffened Door Structure, Ming-Wei Hsieh, Jui-Pin Hung, De-Jen Chen
Investigation On The Blast Resistance Of A Stiffened Door Structure, Ming-Wei Hsieh, Jui-Pin Hung, De-Jen Chen
Journal of Marine Science and Technology
This study was aimed at investigating the blast resistance of a stiffened door structure. For this, a series of finite element transient analysis were performed to predict the dynamic response of blast resistant doors. Current results show that the stiffeners have sustained the majority of the explosive loadings. The effect of stiffener size on the stress state was rated in terms of the ratio of stiffener stress to plate stress, which was enhanced with the increase of web thickness of stiffener. Additional, the highest stresses were shown to occur at the transverse stiffeners near the hinged sides with a maximum …
Optimization Of Diffuser Valves, Chin-Tsan Wang, Pi-Cheng Chang, Chien-Cheng Huang
Optimization Of Diffuser Valves, Chin-Tsan Wang, Pi-Cheng Chang, Chien-Cheng Huang
Journal of Marine Science and Technology
In this study, the width of channel, D, and diffuser angle, , at given diffuser width whose value is 100 m will be studied for steady and unsteady flow conditions. By means of a series of numerical simulations, some findings for diffuser valve will be reported. The diffuser valve with a channel width of D = 300 m and diffuser angle =60º, is a better geometry because of its outstanding capability on suction production of net volume flow. Besides, the larger the Reynolds number is, the greater the suction amount of net volume flow will be. When the aspect ratio …
Profile Design Of Piston Ring Using Inverse Method, Li-Ming Chu, Yuh-Ping Chang, Jung-Hua Yang
Profile Design Of Piston Ring Using Inverse Method, Li-Ming Chu, Yuh-Ping Chang, Jung-Hua Yang
Journal of Marine Science and Technology
This study aims to develop an algorithm for designing the piston ring profile and pressure distribution using an inverse method. The proposed algorithm needs to obtain load and boundary conditions for estimating not only a smooth curve in the piston ring profile, but also in the pressure distribution. The algorithm is developed from Reynolds integral and force balance equations. The least-squares error method, variational method, Gauss-Seidel method and Newton-Raphson method are employed to calculate the piston ring profile. Simulation results reveal that the greater the degree of the polynomial function used, the greater the maximum pressure ( Pmax ), load …