Deformable Overset Grid for Multibody Unsteady Flow Simulation

A deformable overset grid method is proposed to simulate the unsteady aerodynamic problems with multiple flexible moving bodies. This method uses an unstructured overset grid coupled with local mesh deformation to achieve both robustness and efficiency. The overset grid hierarchically organizes the subgrids into clusters and layers, allowing for overlapping/embedding of different type meshes, in which the mesh quality and resolution can be independently controlled. At each time step, mesh deformation is locally applied to the subgrids associated with deforming bodies by an improved Delaunay graph mapping method that uses a very coarse Delaunay mesh as the background graph. The graph is moved and deformed by the spring analogy method according to the specified motion, and then the computational meshes are relocated by a simple one-to-one mapping. An efficient implicit hole-cutting and intergrid boundary definition procedure is implemented fully automatically for both cell-centered and cell-vertex schemes b...

[1]  Charbel Farhat,et al.  Geometric conservation laws for flow problems with moving boundaries and deformable meshes, and their impact on aeroelastic computations , 1996 .

[2]  Charbel Farhat,et al.  Second-order time-accurate and geometrically conservative implicit schemes for flow computations on unstructured dynamic meshes , 1999 .

[3]  C. Allen,et al.  Improved radial basis function fluid–structure coupling via efficient localized implementation , 2009 .

[4]  Tianhang Xiao,et al.  A preconditioned dual time-stepping procedure coupled with matrix-free LU-SGS scheme for unsteady low speed viscous flows with moving objects , 2007 .

[5]  Christian B Allen,et al.  Parallel efficient mesh motion using radial basis functions with application to multi-bladed rotors , 2008 .

[6]  Yasushi Ito,et al.  Generalized Overset Grid Framework for Incompressible Flows , 2006 .

[7]  Gaofeng Wang,et al.  An overset grid method for large eddy simulation of turbomachinery stages , 2014, J. Comput. Phys..

[8]  Kazuhiro Nakahashi.  An Intergrid-Boundary Definition Method for Overset Unstructured Grid Approach , 1999 .

[9]  Tayfun E. Tezduyar,et al.  Simulation of multiple spheres falling in a liquid-filled tube , 1996 .

[10]  Dimitri J. Mavriplis,et al.  Construction of the discrete geometric conservation law for high-order time-accurate simulations on dynamic meshes , 2006, J. Comput. Phys..

[11]  Christian B Allen,et al.  Parallel efficient mesh motion using radial basis functions with application to multi‐bladed rotors , 2008 .

[12]  Chunhua Sheng,et al.  Efficient Mesh Deformation Using Radial Basis Functions on Unstructured Meshes , 2013 .

[13]  Hao Liu,et al.  Flapping wing aerodynamics of a numerical biological flyer model in hovering flight , 2013 .

[14]  Gang Wang,et al.  Improved Point Selection Method for Hybrid-Unstructured Mesh Deformation Using Radial Basis Functions , 2013 .

[15]  H. Bijl,et al.  Mesh deformation based on radial basis function interpolation , 2007 .

[16]  William M. Chan,et al.  Overset grid technology development at NASA Ames Research Center , 2009 .

[17]  Chunyong Yin,et al.  Measuring wing kinematics, flight trajectory and body attitude during forward flight and turning maneuvers in dragonflies , 2003, Journal of Experimental Biology.

[18]  Ning Qin,et al.  Delaunay graph and radial basis function for fast quality mesh deformation , 2015, J. Comput. Phys..

[19]  C. Peskin.  The immersed boundary method , 2002, Acta Numerica.

[20]  Ning Qin,et al.  Fast dynamic grid deformation based on Delaunay graph mapping , 2006 .

[21]  J. L. Steger,et al.  A chimera grid scheme , 2011 .

[22]  Walid Khier,et al.  CFD prediction of air flow past a full helicopter configuration , 2012 .

[23]  Zhi Yang,et al.  Unstructured Dynamic Meshes with Higher-order Time Integration Schemes for the Unsteady Navier-Stokes Equations , 2005 .

[24]  Zhi J. Wang,et al.  A block LU-SGS implicit dual time-stepping algorithm for hybrid dynamic meshes , 2003 .

[25]  V. Venkatakrishnan.  Convergence to steady state solutions of the Euler equations on unstructured grids with limiters , 1995 .

[26]  Christian B. Allen,et al.  Efficient mesh motion using radial basis functions with data reduction algorithms , 2008, J. Comput. Phys..

[27]  K. Nakahashi,et al.  Unstructured dynamic mesh for large movement and deformation , 2002 .

[28]  Charbel Farhat,et al.  A three-dimensional torsional spring analogy method for unstructured dynamic meshes , 2002 .

[29]  J. Batina.  UNSTEADY EULER ALGORITHM WITH UNSTRUCTURED DYNAMIC MESH FOR COMPLEX – AIRCRAFT AERODYNAMIC ANALYSIS , 1991 .

[30]  P. Knupp.  Algebraic mesh quality metrics for unstructured initial meshes , 2003 .

[31]  Xin He,et al.  Applications of dynamic hybrid grid method for three-dimensional moving/deforming boundary problems , 2012 .

[32]  C. Farhat,et al.  Torsional springs for two-dimensional dynamic unstructured fluid meshes , 1998 .

[33]  J. Bonet,et al.  An alternating digital tree (ADT) algorithm for 3D geometric searching and intersection problems , 1991 .

[34]  Mao Sun,et al.  A computational study of the aerodynamics and forewing-hindwing interaction of a model dragonfly in forward flight , 2005, Journal of Experimental Biology.

[35]  Jinsheng Cai,et al.  A parallel viscous flow solver on multi-block overset grids , 2006 .

[36]  Christian B Allen,et al.  Improved Radial Basis Function Fluid-Structure Coupling via Efficient Localised Implementation , 2008 .