List of Articles شبکه سازمان یافته

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  1 - Accuracy assessment of Ro 3rd order and CUSP dissipation schemes to analyze transonic flow around pitching airfoil using structured spring network
  Ali Heydari
  In this article, the unsteady transonic flow analysis with moving boundary is considered to compare dissipation schemes consist of: SCDS scheme, Ro 3rd order and CUSP methods. So that the unsteady, two-dimensional, non-viscous, compressible flow around an oscillating ai More

  In this article, the unsteady transonic flow analysis with moving boundary is considered to compare dissipation schemes consist of: SCDS scheme, Ro 3rd order and CUSP methods. So that the unsteady, two-dimensional, non-viscous, compressible flow around an oscillating airfoil is investigated by solving Euler equations with adaptive grid network. To enhance the ability of moving grid network and prevent interference grids, linear springs are used in tangential and normal direction to the surface. Also the difference between the upwind (Ro) and the central difference CUSP dissipation scheme analysis is studied. The main problem, which occurs to the solution of equations as a result of the phenomenon of shock in central differences, is instability and non-continuity in the solution because of the lack of shock information. To solve the problem the artificial dissipation is used. In this way, the oscillating airfoil motion, the adaptive network and artificial dissipation are modeled. For validation, results are compared with experimental data. Finally, the numerical accuracy is checked. The results show that the of solving the CUSP scheme at the airfoil trailing edge and the shock capturing leads to better accuracy. Manuscript profile
• Open Access Article
  • Abstract Page
  • Full-Text
  
  2 - Sock behavior study in flow around pitching airfoil in transonic regime
  Ali Heydari
  In this study, solution of unsteady flows with moving boundaries is considered. So that two dimensional inviscid unsteady and incompressible flow around an oscillating airfoil is investigated by solving Euler equation using structured adaptive grid network. An adaptive More

  In this study, solution of unsteady flows with moving boundaries is considered. So that two dimensional inviscid unsteady and incompressible flow around an oscillating airfoil is investigated by solving Euler equation using structured adaptive grid network. An adaptive grid is produced using linear spring network, which can be attached to the surface of the object and modeled moving surface. The work initially focused on production of adaptive spring grid network and different state of adaptive grid production is investigated. After investigations of mesh and time step independency, the results are compare with experiments. Also, to show the advantages of structured adaptive grid network, the results are compared with unstructured adaptive grid network. The results show that use of adaptive structured network leads to increasing the speed of solution while maintaining the accuracy. Also it can be seen that in pitching airfoil, the shock behavior depends on the direction of movement, instant angle and mean angle of oscillation. Manuscript profile