<?xml version="1.0" encoding="UTF-8"?>
<issues>
  <issue published="true" current="false" identification="title">
    <title locale="en_US">Vol.24, No.3, September 2008</title>
    <number>3</number>
    <volume>24</volume>
    <year>2008</year>
    <date_published>2008-09-01</date_published>
    <section>
      <title locale="en_US">Vol.24, No.3, September 2008</title>
      <article>
        <title locale="en_US">COMPARISON OF FATIGUE TENSILE PROPERTIES OF SCRIMP-GFRP AND HLUP-GFRP</title>
        <abstract locale="en_US">    Seemann Composites Resin Infusion Molding Process (called SCRIMPTM for short) is a resin transfer molding process which is commonly used in the manufacture of yachts. Fiber-Reinforced Plastic (called FRP for short) manufactured by using SCRIMP has higher fiber-volume-content than that manufactured by using Hand Lay-Up Process (called HLUP for short). In general, the tensile strength and fatigue strength are used to compare the tensile properties of SCRIMP-FRP and HLUP-FRP. In this paper, another viewpoint of comparison is used to compare their tensile properties, especially their fatigue tensile properties. Experiments on the fatigue life and damage phenomena in SCRIMP-FRP and HLUP-FRP were performed. Experimental results show that if the same fibers are used in SCRIMP-FRP and HLUPFRP, SCRIMP-FRP will be much thinner than HLUP-FRP and few air bubbles exist inside SCRIMP-FRP. Although SCRIMP-FRP has higher tensile strength than HLU-FRP, the tensile forces they can bear are approached. That means, processes do not affect the tensile load carrying capacities of FRP. However, SCRIMP-FRP exhibits shorter fatigue life than HLUP-FRP. The reason for that is discussed in this paper and qualitative analysis is performed to explain the author’s contentions. Keywords : FRP, Fatigue, SCRIMP.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>H.-J.</firstname>
          <lastname>Lin</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>C.-I</firstname>
          <lastname>Liao</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">THICKNESS EFFECT ON LOW-ASPECT-RATIO WING AERODYNAMIC CHARACTERISTICS AT A LOW REYNOLDS NUMBER</title>
        <abstract locale="en_US">This paper presents the study of aerodynamic performance about low-aspect-ratio wings at a low Reynolds number in wind tunnel testing. The aerodynamic properties, including lift, total drag, lift-to-drag ratio and induced drag were measured and analyzed for detailed investigations. Two forms of nonlinear equations of lift curves were reported for comparison. The effect of airfoil thickness was found to be significant on aerodynamic characteristics for all wings tested. The lift due to tip vortices was prominent for wings of AR = 1.0 and their stall angles were all larger than 20°, which was mainly augmented by tip vortices shed from the wing tips. Keywords : Low Reynolds number, Low aspect ratio, Vortex lift.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>F. B.</firstname>
          <lastname>Hsiao</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>C. Y.</firstname>
          <lastname>Lin</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>Y. C.</firstname>
          <lastname>Liu</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>D. B.</firstname>
          <lastname>Wang</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>C. C.</firstname>
          <lastname>Hsu</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>C. H.</firstname>
          <lastname>Chiang</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">SHEAR HORIZONTAL PIEZOELECTRIC WAVES IN A PIEZOCERAMIC PLATE IMPERFECTLY BONDED TO TWO PIEZOCERAMIC HALF-SPACES</title>
        <abstract locale="en_US">We analyze the propagation of shear horizontal (SH) piezoelectric waves guided by a plate of polarized piezoceramics between two piezoceramic half-spaces with imperfectly bonded interfaces. The interfaces are described by the so-called shear-lag model with an elastic constant characterizing the interface physical behavior. Exact dispersion relations are obtained. It is found that the waves are sensitive to the physical nature of the interfaces. The results are useful for acoustic wave devices. Keywords : Piezoelectricity, Wave, Plate.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>Z. G.</firstname>
          <lastname>Chen</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>Y. T.</firstname>
          <lastname>Hu</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>J. S.</firstname>
          <lastname>Yang </lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">LONG-WAVE PERTURBATION METHOD TO INVESTIGATE NONLINEAR STABILITY OF THE THIN POWER LAW LIQUID FILM FLOWING DOWN ON A VERTICAL CYLINDER</title>
        <abstract locale="en_US">The influence of both the flow index and the cylinder size on the nonlinear hydrodynamic stability of a thin power law liquid film flowing down along the surface of a vertical cylinder is investigated. The long-wave perturbation method is employed to solve for generalized nonlinear kinematic equations with a free film interface. The normal mode approach is first used to compute the linear stability solution for the film flow. The method of multiple scales is then used to obtain the weakly nonlinear dynamics of the film flow for stability analysis. The stability criteria are discussed theoretically and numerically and stability diagrams are obtained. The modeling results indicate that by increasing the flow index and increasing the radius of the cylinder the film flow can become relatively more stable as traveling down along the vertical cylinder. Keywords : Thin film, Stability analysis, Flow index, Power law liquid.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>P.-J.</firstname>
          <lastname>Cheng</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>K.-C.</firstname>
          <lastname>Liu</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">THE VIBRATION REDUCTION ANALYSIS OF A ROTATING MECHANISM DECK SYSTEM</title>
        <abstract locale="en_US">In this paper, an optimized position of a mass-spring-damper vibration absorber is proposed for a rotating mechanism device (such as optical disk drive or rotary-wing and deck coupled system). A nonlinear 3-D theoretical model for a deck is established by Lagrange’s equation. A 2-bladed rotor and deck (foundation) coupled aeroelastic system with vibration reduction device is presented and studied as well. The analytical solution is obtained by the Multiple-scales method for the case of no vibration absorber. The numerical results in time and frequency domain and with/no absorber are acquired. This research provides a theoretical background for the preliminary vibration reduction design for industries. It is found that the existing disk drives vibration can be reduced by simply adding the absorber at the end corner isolator of the deck, but without changing the main configurations. This will not only save costs but also increase testing efficiency, achieving the most cost-effective vibration reduction result. Keywords : Vibration absorber, Rotating Fundation, Rotary-wing Blade.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>Y.-R.</firstname>
          <lastname>Wang</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>T.-H.</firstname>
          <lastname>Chen</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">COMPARISON OF COMBUSTION MODELS IN CLEANROOM FIRE</title>
        <abstract locale="en_US">In this paper, the cleanroom fire simulation in a semi-conductor factory is investigated by using the commercial computational fluid dynamics (CFD) code. We using three different combustion models in the fire simulation. The combustion models including the volume heat source (VHS) model, the eddy break-up (EBU) model and the presumed probability density function (prePDF) model are considered to predict the cleanroom fire. The turbulence models coupled with different combustion models, while the radiation model is coupled with the turbulent combustion processes. Additionally, the discrete transfer radiation method (DTRM) is used in the global radiation heat exchange. For the fire simulation, the different combustion models are evaluated for their performance and compared with the experimental data from the literature to verify. Thus, these numerical simulations can be adopted as a useful tool to design and optimize the smoke control strategy in cleanroom fire. Keywords : Cleanroom, Fire, Numerical simulation, Combustion model, Radiation model.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>Y.-L.</firstname>
          <lastname>Huang</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>H.-R.</firstname>
          <lastname>Shiu</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>S.-H.</firstname>
          <lastname>Chang</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>W.-F.</firstname>
          <lastname>Wu</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>S.-L.</firstname>
          <lastname>Chen</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">FLAME PROPAGATION WITH HYDRODYNAMIC INSTABILITY IN VORTICAL FLOWS</title>
        <abstract locale="en_US">The interaction between a flame and vortices has been investigated by means of a front-tracking method. Extending previous studies on the role of hydrodynamic (Darrieus-Landau) instability in the wrinkling of flame surface at the incipient stage, we have further investigated the flame dynamics in the course of long-time evolution when interactions between the flame front, the instability, and the vortical flow result in highly convoluted flame configurations. It is shown that, with the inherent mechanisms of merging and dividing of flame cells at multiple scales that are generated by the hydrodynamic instability, propagation of flame wrinkles can evolve to a quasi-stable state characterized by a solitary wave or chaotic motion associated with corrugated front. If the vortical flow is sufficiently strong, however, the flame geometry is contorted by the vortices while the effect of hydrodynamic instability degenerates. Therefore, according to the relative magnitudes of the intensity of hydrodynamic instability, determined by the density ratio as well as the curvature parameter that is relevant to the flame thickness, and the strength of the vortices, the interaction pattern can be classified as flame-instability dominated, flow dominated, and a hybrid of the two. Keywords : Flame propagation, Flame-vortex interaction, Hydrodynamic instability, Darrieus-Landau instability.</abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>K.-L.</firstname>
          <lastname> Pan</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">FAILURE MECHANISM AND BEARING CAPACITY OF SHALLOW FOUNDATION ON POORLY CEMENTED SANDSTONE</title>
        <abstract locale="en_US"> This paper aims to investigate the failure mechanism of a shallow foundation on poorly cemented sandstone and to propose an upper bound solution for the bearing capacity of the foundation. A series of laboratory material and load-bearing model tests with specimens made of artificial rock mimic undisturbed natural poorly cemented sandstone. Based on a series of load-bearing model tests, bearing behavior and progressive failure mechanisms are investigated. It was found that the bearing behavior on poorly cemented sandstone is distinct from the cases on hard rock or on soil, and exhibits both plasticity and brittle characteristics. It is noted that the bearing capacity formulas for a shallow foundation commonly used for soil or hard rock are not appropriate for the case of poorly cemented soft sandstone. Based on the observed failure mechanism, a simplified plastic collapse mechanism is proposed and an upper-bound solution on the basis of a multi-block translation mechanism is formulated. It is shown that the upper bound solution agrees well with the experimental bearing capacity as long as a proper non-associated flow rule is adopted. Keywords : Poorly cemented sandstone, Model bearing test, Ultimate bearing capacity, Failure mechanism.  </abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>J.-C.</firstname>
          <lastname>Chang</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>J.-J.</firstname>
          <lastname>Liao</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>Y.-W.</firstname>
          <lastname>Pan</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">MHD MIXED CONVECTION OF VISCOELASTIC FLUID OVER A STRETCHING SHEET WITH OHMIC DISSIPATION</title>
        <abstract locale="en_US"> A magnetic hydrodynamic (MHD) mixed convection of an incompressible viscoelastic fluid over a stretching sheet with ohmic dissipation is studied. The buoyant effect and the electric number E1 couple with magnetic parameter M to represent the dominance of the ohmic effect are presented in governing equations which is the main contribution by this study. The similarity transformation, the finitedifference method have been used to analyze the present problem. The numerical solutions of the flow velocity distributions, temperature profiles and the important wall unknown values of f ''(0) and ? '(0) are carried out. Keywords : Viscoelastic fluid, Stretching sheet, Magnetic field, Mixed convective, Ohmic dissipation, Finite-difference.  </abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>K.-L. </firstname>
          <lastname>Hsiao</lastname>
          <email>email@email.org</email>
        </author>
      </article>
      <article>
        <title locale="en_US">VORTEX SIMULATIONS OF THE FLOW-FIELD OF A FLAT PLATE WITH A NON-ZERO ANGLE OF ATTACK</title>
        <abstract locale="en_US"> A Lagrangian style vortex simulation technique is used to study the flow fields past a stationary flat plate at various angles of attack in the range 1° to 90°. Time mean values of oscillating lift and drag coefficients, and the Strouhal number versus angle of attack are computed and compared with experimental results. Time-mean and root-mean-square values of stream-wise and transverse velocities in the wake region are also calculated. Self-similar defect velocity distribution is obtained far downstream. Owing to the interaction of free shear layers, highly root-mean-square values of velocities appear at the downstream vertex of the triangular low velocity region, which exits behind an inclined flat plate. Keywords : Vortex simulation, Flat plate, Wake, Strouhal number.  </abstract>
        <date_published>2008-09-01</date_published>
        <author primary_contact="false">
          <firstname>C.-C.</firstname>
          <lastname>Hsu</lastname>
          <email>email@email.org</email>
        </author>
        <author primary_contact="false">
          <firstname>C.-I</firstname>
          <lastname>Huang</lastname>
          <email>email@email.org</email>
        </author>
      </article>
    </section>
  </issue>
</issues>