scholarly journals Numerical Study on Unsteady Pressure Distribution on Bulk Carrier in Head Waves with Forward Speed

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Kyung-Kyu Yang ◽  
Beom-Soo Kim ◽  
Yonghwan Kim ◽  
Masashi Kashiwagi ◽  
Hidetsugu Iwashita
Keyword(s):  
Experimental Data ◽  
Pressure Distribution ◽  
Harmonic Component ◽  
Grid Method ◽  
Cartesian Grid ◽  
Forward Speed ◽  
Unsteady Pressure ◽  
Cartesian Grid Method ◽  
Head Waves ◽  
Wave Induced

This study deals with wave-induced unsteady pressure on a ship moving with a constant forward speed in regular head waves. Two different numerical methods are applied to solve wave–ship interaction problems: a Rankine panel method which adopts velocity potential, and a Cartesian-grid method which solves the momentum and mass conservation equations under the assumption of inviscid and incompressible fluids. Before comparing l1ocal pressure distributions, the computational methods are validated for global quantities, such as ship motion responses and added resistance, by comparison with available experimental data. Then, the computational results and experimental data are compared for hydrodynamic pressure, particularly focusing on the magnitude of the first-harmonic component in different sections and vertical locations. Furthermore, the Cartesian-grid method is used to simulate the various wave-amplitude conditions, and the characteristics of the zeroth-, first-, and second-harmonic components of wave-induced pressure are investigated. The nonlinearity of pressure distribution is observed mostly from the pressure near the still-water-level of the ship bow and the normalized first-harmonic component of wave-induced pressure decreases as the wave steepness increases. Lastly, to understand the local characteristics of wave-induced unsteady pressure, the time-averaged added pressure and added local force are analyzed. It is found that the major contribution of the time-averaged added local force that occurs around the ship stem above the design waterline.

Three-Dimensional Cartesian Grid Method for the Simulations of Flows with Shock Waves in the Domains with Varying Boundaries

2020 ◽  
pp. 2050046
Author(s):  
V. V. Elesin ◽  
D. A. Sidorenko ◽  
P. S. Utkin
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Wave Propagation ◽  
Three Dimensional ◽  
Grid Method ◽  
Cartesian Grid ◽  
Computational Cell ◽  
Cartesian Grid Method ◽  
Moving Particle

This paper is devoted to the development and quantitative evaluation of the properties of the numerical algorithm of the Cartesian grid method for three-dimensional (3D) simulation of shock-wave propagation in areas of varying shape. The detailed description of the algorithm is presented. The algorithm is relatively simple to implement and does not require solving the problem of determination of the shape of the body’s boundary intersection with regular computational cell. The accuracy of the algorithm is demonstrated by comparing the simulated and experimental data in the problems of the interaction of a shock wave (SW) with a nonmoving sphere and a moving particle.

Development of Cartesian grid method for simulation of violent ship-wave interactions

2016 ◽  
Vol 28 (6) ◽  
pp. 1003-1010
Author(s):  
Changhong Hu ◽  
Cheng Liu
Keyword(s):  
Grid Method ◽  
Cartesian Grid ◽  
Wave Interactions ◽  
Ship Wave ◽  
Cartesian Grid Method

Cartesian Grid Method for Moderate-Reynolds-Number Flows Around Complex Moving Objects

AIAA Journal ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Jo-Einar Emblemsvag ◽  
Ryuta Suzuki ◽  
Graham V. Candler
Keyword(s):  
Reynolds Number ◽  
Moving Objects ◽  
Grid Method ◽  
Cartesian Grid ◽  
Cartesian Grid Method ◽  
Moderate Reynolds Number ◽  
Reynolds Number Flows

Development of Cooling Structures for Blu-Ray Disc Compatible Optical Disc Drives Using Computational Fluid Dynamics Based on Cartesian Grid Method

2007 ◽  
Author(s):  
Nobuyuki Isoshima ◽  
Takayuki Fujimoto ◽  
Yukinobu Abe ◽  
Masatoshi Watanabe ◽  
Yoshiaki Yamauchi ◽  
...  
Keyword(s):  
Laser Diode ◽  
High Speed ◽  
High Performance ◽  
Flow Simulation ◽  
Grid Method ◽  
Ambient Air ◽  
Cartesian Grid ◽  
Optical Disc ◽  
Rotating Disc ◽  
Cartesian Grid Method

High-performance, simple cooling structures for optical disc drives compatible with the Blu-ray disc (BD) were developed using unsteady numerical flow simulation based on the Cartesian grid method. In the new structure, an additional hole in the tray outside of the disc induced a secondary upward flow, which is caused by a pressure difference and rotating-disc flow. The secondary flow decreases the ambient air-temperature of the laser diode below the hole, and furthermore it increases the velocity around the laser diode and enhances the heat transfer rate. The experimental results indicate that the cooling effect of the laser diode increases, and the disc vibration is not influenced by the additional hole in the tray. The cooling structures are applied to the so-called super-multi BD drive, which achieved 4X high-speed recording for the first time in the industry.

scholarly journals A sharp-interface Cartesian grid method for viscoelastic fluid flow in complex geometry

2016 ◽  
Vol 234 ◽  
pp. 82-104 ◽  
Author(s):  
Wei Yi ◽  
Daniel Corbett ◽  
Xue-Feng Yuan
Keyword(s):  
Fluid Flow ◽  
Viscoelastic Fluid ◽  
Complex Geometry ◽  
Grid Method ◽  
Cartesian Grid ◽  
Sharp Interface ◽  
Cartesian Grid Method

scholarly journals A Direct Discretization Approach near Wall Boundaries for Flow with Heat Transfer Using a Cartesian Grid Method

2013 ◽  
Vol 79 (803) ◽  
pp. 1219-1231 ◽  
Author(s):  
Norikazu SATO ◽  
Shintaro TAKEUCHI ◽  
Takeo KAJISHIMA ◽  
Masahide INAGAKI ◽  
Nariaki HORINOUCHI
Keyword(s):  
Heat Transfer ◽  
Grid Method ◽  
Cartesian Grid ◽  
Cartesian Grid Method ◽  
Near Wall
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