International Journal for Numerical Methods in Fluids

Cover image for Vol. 71 Issue 12

30 April 2013

Volume 71, Issue 12

Pages 1475–1608

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. Optimization of unsteady incompressible Navier–Stokes flows using variational level set method (pages 1475–1493)

      Yongbo Deng, Ping Zhang, Yongshun Liu, Yihui Wu and Zhenyu Liu

      Version of Record online: 10 AUG 2012 | DOI: 10.1002/fld.3721

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      This paper presents optimization of unsteady Navier-Stokes flow using the variational level set method for the first time. By coupling the level set method with unsteady Navier-Stokes equations, the solid–fluid interface and the zero velocity condition in the solid domain have been implemented implicitly. This optimization method can be applied to optimize flows with and without body forces.

    2. A method to carry out shape optimization with a large number of design variables (pages 1494–1508)

      Nikhil Kumar, Anant Diwakar, Sandeep Kumar Attree and Sanjay Mittal

      Version of Record online: 23 AUG 2012 | DOI: 10.1002/fld.3722

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      A new method for shape optimization with relatively large number of design variables is proposed. For effective utilization of a richer design space, it is proposed that the number of design variables be increased gradually. This method is demonstrated by designing high lift airfoils for Re = 1 × 103 and 1 × 104 at a = 4°. Corrugations on the upper surface of the optimal airfoil promote generation of small vortices that lead to higher aerodynamic performance.

    3. Two-dimensional non-Newtonian injection molding with a new control volume FEM/volume of fluid method (pages 1509–1523)

      Carlos Salinas, Diego A. Vasco and Nelson O. Moraga

      Version of Record online: 23 AUG 2012 | DOI: 10.1002/fld.3723

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      A new conservative nondispersive interface tracking method based on volume of fluid and control volume finite-element method is developed. The method is implemented in three stages: accumulation, distribution, and correction. The proposed method is applied to describe the fluid mechanics and heat transfer for a non-isothermal injection molding process of non-Newtonian fluids in a two-dimensional cavity.

    4. Moving grid method for numerical simulation of stratified flows (pages 1524–1545)

      S. Koltakov and O. B. Fringer

      Version of Record online: 29 AUG 2012 | DOI: 10.1002/fld.3724

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      We develop a second-order accurate Navier–Stokes solver based on r-adaptivity of the underlying numerical discretization. The motion of the mesh is based on the fluid velocity field; however, certain adjustments to the Lagrangian velocities are introduced to maintain the quality of the mesh. The adjustments are based on the variational approach of energy minimization to redistribute grid points closer to the areas of rapid solution variation.

    5. Comparative study of implicit and subgrid-scale model large-eddy simulation techniques for low-Reynolds number airfoil applications (pages 1546–1565)

      Daniel J. Garmann, Miguel R. Visbal and Paul D. Orkwis

      Version of Record online: 23 AUG 2012 | DOI: 10.1002/fld.3725

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      The conclusions of this work affirm the application of high fidelity, implicit large-eddy simulation without subgrid-scale modeling to a broader class of low-Reynolds number, transitional and turbulent flows such as those encountered by micro-air vehicles or low-pressure turbine blades.

    6. A well-balanced weighted essentially non-oscillatory scheme for pollutant transport in shallow water (pages 1566–1587)

      Gang Li, Jinmei Gao and Qiuhua Liang

      Version of Record online: 7 SEP 2012 | DOI: 10.1002/fld.3726

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      We present a well-balanced finite difference weighted essentially non-oscillatory scheme to transport and diffusion of pollutant in shallow water flows. The scheme balances exactly the flux gradients and the source terms. Extensive numerical experiments on uniform and curvilinear meshes strongly suggest that high resolution results are achieved for water depth and pollutant concentration. The scheme is also efficient and robust and can be applied for practical numerical simulation of pollutant transport phenomena in shallow water flows.

    7. An immersed boundary method wall model for high-Reynolds-number channel flow over complex topography (pages 1588–1608)

      William Anderson

      Version of Record online: 28 AUG 2012 | DOI: 10.1002/fld.3727

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      A new immersed boundary method wall model has been developed and implemented in a large-eddy simulation code. The figure shows a turbulent velocity field responding to an array of prismatic shapes that represent a synthetic city.