Applications of anisotropic unstructured mesh adaption insupersonic combustion simulations
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摘要: 采用各向异性网格自适应求解技术,将其应用于DLR超燃冲压发动机燃烧室中的超燃模拟.开展了3个算例,包括采用滑移壁面条件的燃烧室冷流场模拟、采用无滑移壁面条件的冷流场模拟及采用无滑移壁面条件的反应流模拟.模拟中,各向异性网格自适应计算捕捉到了如激波、射流、边界层、火焰面等具有各向异性特征的大梯度区域,并利用各向异性网格进行了很好的加密.对比利用各向同性网格的初始流场计算,各向异性网格自适应计算使基于滑移条件、无滑移条件的冷流计算及反应流计算的网格单元数量分别下降了36.2%,36.4%和36.8%,有效降低了计算规模,而且流场大梯度区域的计算结果更准确,辨析度更好.结果表明:对于像超燃这类具有各向异性特征的问题,各向异性网格系统比各向同性网格系统有更好的计算效率及准确性,同时也表明基于Mach数场构造的各向异性网格系统可以有效应用于超燃计算.Abstract: Anisotropic unstructured mesh adaption has been introduced and used in 2-D simulations of supersonic combustion in the DLR (Deutsches Zentrum für Luft-und Raumfahrt) scramjet combustion chamber. Three cases of non-reaction flow simulation with slip wall conditions, non-reaction flow simulation with non-slip wall conditions and reaction flow simulation (with nonslip wall conditions) were carried out. In the calculations, large gradient areas with anisotropic characteristics, such as shockwaves, jet-flows, boundary layers, and flames, were detected and well refined with anisotropic meshes. As a result, compared with the initial simulation using an isotropic mesh, element numbers were reduced by 36.2%, 36.4% and 36.8%, respectively, in case of slip conditions, nonslip conditions and reactions, meanwhile the accuracy and resolution in large gradient areas was even better. The results show high efficiency and high accuracy of anisotropic mesh approach compared with the isotropic mesh, for the problems with significant anisotropic characteristics such as supersonic combustion. It has been demonstrated that Hessian metrics based on Mach numbers can be used to generate anisotropic meshes for the supersonic combustion simulation.
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Key words:
- anisotropic unstructured mesh /
- mesh adaption /
- hessian metric /
- supersonic combustion /
- scramjet
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[1] Oevermann M.Numerical investigation of turbulent hydrogen combustion in a SCRAMJET using flamelet modeling[J].Aerospace Science and Technology,2000,4(7):463-480. [2] Castro-Diaz M J,Hecht F,Mohammadi B,et al.Anisotropic unstructured mesh adaption for flow simulations[J].International Journal for Numerical Methods in Fluids,1997,25(4):475-491. [3] Belhamadia Y,Fortin A,Chamberland É.Three-dimensional anisotropic mesh adaptation for phase change problems[J].Journal of Computational Physics,2004,201(2):753-770. [4] Mura A,Izard J F.Numerical simulation of supersonic nonpremixed turbulent combustion in a scramjet combustor model[J].Journal of Propulsion and Power,2010,26(4):858-868. [5] 邹建锋,盛东,邢菲,等.基于各向异性非结构网格的超声速流动自适应计算[J].空气动力学学报,2013,31(1):47-51. ZOU Jianfeng,SHENG Dong,XIN Fei,et al.Anisotropic unstructured mesh adaption for supersonic flow simulation[J].Acta Aerodynamica Sinica,2013,31(1):47-51.(in Chinese) [6] Habashi W G,Dompierre J,Bourgault Y,et al.Anisotropic mesh adaptation:towards user-independent,mesh-independent and solver-independent CFD:Part Ⅰ general principles[J].International Journal for Numerical Methods in Fluids,2000,32(6):725-744. [7] Dompierre J,Vallet M,Bourgault Y,et al.Anisotropic mesh adaptation:towards user-independent,mesh-independent and solver-independent CFD:Part Ⅲ unstructured meshes[J].International Journal for Numerical Methods in Fluids,2002,39(8):675-702. [8] Tam A,Ait-Ali-Yahia D,Robichaud M,et al.Anisotropic mesh adaptation for 3D flows on structured and unstructured grids[J].Computer Methods in Applied Mechanics and Engineering,2000,189(4):1205-1230. [9] Dolejsi V.Anisotropic mesh adaption technique for viscous flow simulation[J].East West Journal of Numerical Mathematics,2001,9(1):1-24. [10] Bottasso C.Anisotropic mesh adaption by metric-driven optimization[J].International Journal for Numerical Methods in Engineering,2004,60(3):597-639. [11] Dolejsi V,Felcman J.Anisotropic mesh adaptation for numerical solution of boundary value problems[J].Numerical Methods for Partial Differential Equations,2004,20(4):576-608. [12] Frey P,Alauzet F.Anisotropic mesh adaptation for CFD computations[J].Computer Methods in Applied Mechanics and Engineering,2005,194(48/49):5068-5082. [13] Remacle J,Li X,Shephard M,et al.Anisotropic adaptive simulation of transient flows using discontinuous Galerkin methods[J].International Journal for Numerical Methods in Engineering,2005,62(7):899-923. [14] Vassilevski Y,Dyadechko V,Lipnikov K,et al.Hessian-based anisotropic mesh adaptation in domains with discrete boundaries[J].Russian Journal of Numerical Analysis and Mathematical Modelling,2005,20(4):391-402. [15] Lipnikov K,Vassilevski Y.Analysis of hessian recovery methods for generating adaptive meshes[C]//Philippe P,Peday.Proceedings of the 15th International Meshing Roundtables.Berlin Heidelbery:Springer-Verlay,2006:163-171. [16] Waidmann W,Alff F,Böhm M,et al.Supersonic combustion of hydrogen/air in a SCRAMJET combustion chamber[J].Space Technology,1995,15(6):421-429. [17] Mitchella D,Higgins K,Smith N S A.Radical-farming scramjet combustion-comparison of numerical predictions with shock tunnel measurements[R].AIAA 2006-8022,2006. [18] Berglund M,Fureby C.LES of supersonic combustion in a scramjet engine model[J].Proceedings of the Combustion Institute,2007,31(2):2497-2504.
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