Browsing by Author "Huang, Shang-Hao"

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An enhancement of the back region forced convection heat transfer rates of a reciprocating curved channel with a rib by the ALE method
(2013-12-01)
Fu, Wu-Shung
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Lai, Yu-Chih
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Huang, Shang-Hao
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機械工程學系
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Department of Mechanical Engineering
An enhancement of the back region forced convection heat transfer rates of a reciprocating curved channel with a rib by the ALE method is investigated numerically. In order to avoid damage caused by a huge difference of heat transfer rates between the front and back regions of a reciprocating curved channel, a rib is selected and installed at an appropriate location to enhance the heat transfer rate of the back region. In the ALE method, the generalized minimal residual method preconditioned by the mesh free pressure convection-diffusion in which the pressure terms are arranged in a finite element linearized matrix system is used to solve governing equations. The results show that the heat transfer rate of the back region is indeed enhanced by the installation of the rib at an appropriate location. (C) 2013 Elsevier Ltd. All rights reserved.
An investigation of effects of heights and a length on natural convection of three dimensional parallel plates with a heated bottom surface by a CUDA computation platform
(2013-12-01)
Fu, Wu-Shung
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Huang, Shang-Hao
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Wang, Wei-Hsiang
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機械工程學系
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Department of Mechanical Engineering
Effects of heights and a length on natural convection of three dimensional parallel plates with a heated bottom surface are investigated numerically. The compressibility of fluid induced by a high temperature difference is taken into consideration for simulating more realistic situations, and then the Boussinesq assumption is not necessary to be adopted. Methods of the Roe scheme, preconditioning and dual time stepping matching the method of LUSGS are simultaneously used to solve the compressible flow problem. Non-reflecting boundary conditions are held on apertures to prevent reflections from apertures induced by pressure waves. A CUDA computational platform is used to economize massive computing time. Under a low height case, the flow field is restricted by the shear force caused by the low height and displays a stable situation. Oppositely, under a high height case the flow field indicates active behaviors and an irregular situation is observed. (C) 2013 Elsevier Ltd. All rights reserved.
An investigation of natural convection in parallel square plates with a heated bottom surface by an absorbing boundary condition
(2013-01-01)
Fu, Wu-Shung
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Wang, Wei-Hsiang
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Li, Chung-Gang
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Huang, Shang-Hao
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機械工程學系
A study of natural convection in three dimensional square plates is investigated numerically. Several open boundaries co-exist in the physical domain, and a non-reflecting boundary condition applied at the aperture is no longer suitable for solving the problem of this study. An absorbing boundary condition is then adopted and modified in the solution processes. Methods of the Roe scheme, preconditioning and dual time stepping matching LSUGS scheme are used to solve a situation of a low speed compressible flow. The geometry of the physical model is the parallel square plates, and the parameter of Rayleigh number is not high, and then phenomena observed are almost symmetrical. The results of the work have good agreements with the experimental results of a previous paper. (c) 2012 Elsevier Ltd. All rights reserved.
An investigation of natural convection of three dimensional horizontal parallel plates from a steady to an unsteady situation by a CUDA computation platform
(2012-08-01)
Fu, Wu-Shung
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Wang, Wei-Hsiang
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Huang, Shang-Hao
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機械工程學系
;
Department of Mechanical Engineering
"The heat transfer of natural convection in three dimensional horizontal parallel plates with a heated bottom surface is investigated numerically. For enlarging the application domain, the compressibility of the fluid is taken into consideration instead of the Boussinesq assumption. Numerical methods of the Roe scheme, preconditioning and dual time stepping are adopted for solving governing equations of a low speed compressible flow. A non-reflection condition is used at both apertures in order to decrease computational grids and a CUDA computational platform is developed to economize massive computing time. Variations of thermal and flow fields are examined in detail. The results show that accompanied with elongating the length of the heated bottom surface, both thermal and flow fields are changed from a steady to an unsteady situation. (C) 2012 Elsevier Ltd. All rights reserved."
An investigation of unsteady flow reversal of natural convection in vertical parallel plates by the modified local one-dimensional inviscid relations method
(2015-07-01)
Fu, Wu-Shung
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Huang, Shang-Hao
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Li, Chung-Gang
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機械工程學系
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Department of Mechanical Engineering
An unsteady flow reversal of natural convection in vertical parallel plates with an asymmetrically heated wall is investigated numerically. For clarifying the occurrence of flow reversal, the width of the plates is regarded as a variable, and the non-reflecting boundary condition is adopted at apertures. The methods of the Roe scheme, preconditioning and dual time stepping matching LUSGS are siinultaneously used to solve governing equations which are available for a low speed compressible flow problem. The flow reversal is observed under broad width situations and absent under narrow width situations. Distributions of the pressure differences at the apertures are revealed to indicate the occurrence of flow reversal. The present Nusselt numbers, which mean time and area-averaged ones, display relatively good agreement with those of the existing works. (C) 2015 Elsevier Ltd. All rights reserved.
Analog LCOS SLM devices for AR display applications
(1970-01-01)
Fan-Chiang, Kuan-Hsu
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Huang, Shang-Hao
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Shen, Che-Yung
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Wang, Hsing-Lung
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Li, Yuet-Wing
Liquid crystal on silicon (LCOS) device is a potential candidate for spatial light modulators (SLMs) due to its high resolution and the wide range of tunable phase retardation. Besides the telecom applications, SLM is also very promising for display applications, especially for the augmented reality (AR) displays. In this paper, we will discuss the advantages of analog LCOS SLM compared with the digital one. A 0.6-in short-loop sample test result with precise cell gap controlled is discussed. A fast liquid crystal with high birefringence that attains less than 2.5-ms full-on-full-off response time is also introduced. Regarding the computer-generated hologram (CGH), a new algorithm called multiconstraints angular spectrum algorithm (MASA) is proposed to enhance the image quality of dual-plane holographic projection.
Effects of a porous medium on forced convection of a reciprocating curved channel
(2014-11-01)
Fu, Wu-Shung
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Chen, Chung-Jen
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Lai, Yu-Chih
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Huang, Shang-Hao
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機械工程學系
Enhancement of heat transfer rates of a reciprocating curved channel partially installed by a porous medium is investigated numerically. The distribution of heat transfer rates on the heat surface of the reciprocating curved channel is rather non-uniform that easily causes a thermal damage to destroy the channel. A method of using the porous medium to enhance heat transfer rates of the channel is then developed to solve the thermal damage. The arbitrary Lagrangian-Eulerian method is firstly modified for treating a moving boundary problem of the porous medium. Main parameters of Reynolds numbers, porosities, frequencies and amplitudes are examined. The results show that the enhancements of heat transfer rates of most porous medium situations are achieved. However, heat transfer rates of a few porous medium situations are unexpectedly inferior to those of without porous medium situations. (C) 2014 Elsevier Ltd. All rights reserved.
Hybrid light field head-mounted display using time-multiplexed liquid crystal lens array for resolution enhancement
(2019-01-21)
Chou, Ping-Yen
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Wu, Dui-Yi
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Huang, Shang-Hao
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Wang, Chun-Ping
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Qin, Zong
In recent years, head-mounted display technologies have greatly advanced. In order to overcome the accommodation-convergence conflict, light field displays reconstruct three-dimensional (3D) images with a focusing cue but sacrifice resolution. In this paper, a hybrid head-mounted display system that is based on a liquid crystal microlens array is proposed. By using a time-multiplexed method, the display signals can be divided into light field and two-dimensional (2D) modes to show comfortable 3D images with high resolution compensated by the 2D image. According to the experimental results, the prototype supports a 12.28 ppd resolution in the diagonal direction, which reaches 82% of the traditional virtual reality (VR) head-mounted display (HMD). (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement