Computation of aeroacoustic sources for a Gulfstream G550 nose landing gear model using adaptive FEM.

*(English)*Zbl 1390.76831Summary: This work presents a direct comparison of unsteady, turbulent flow simulations with measurements performed using a Gulfstream G550 nose landing gear model. The experimental campaign, which was carried out by researchers from the NASA Langley Research Center, provided a series of detailed, well documented wind-tunnel measurements for comparison and validation of computational fluid dynamics (CFD) and computational aeroacoustics (CAA) methodologies. Several computational efforts were collected and presented at the Benchmark for Airframe Noise Computation workshops, BANC-I and II. For our simulations, we used a general Galerkin finite element method (G2), where no explicit subgrid model is used, and where the computational mesh is adaptively refined with respect to a posteriori estimates of the error in a quantity of interest, here the source term in Lighthill’s equation. The mesh is fully unstructured and the solution is time-resolved, which are key ingredients for solving problems of industrial relevance in the field of aeroacoustics. Moreover, we choose to model the boundary layers on the landing gear geometry with a free-slip condition for the velocity, which we previously observed to produce good results for external flows at high Reynolds numbers, and which considerably reduces the amount of cells required in the mesh. The comparisons presented here are an attempt to quantify the accuracy of our models, methods and assumptions; to that end, several results containing both time-averaged and unsteady flow quantities, always side by side with corresponding experimental values, are reported. The main finding is that we are able to simulate a complex, unsteady flow problem using a parameter-free methodology developed for high Reynolds numbers, external aerodynamics and aeroacoustics applications.

##### MSC:

76Q05 | Hydro- and aero-acoustics |

76M10 | Finite element methods applied to problems in fluid mechanics |

##### Keywords:

landing gear noise; computational fluid dynamics; computational aeroacoustics; adaptive finite element methods; Turbulence; CAA; CFD; FEM
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\textit{R. Vilela de Abreu} et al., Comput. Fluids 124, 136--146 (2016; Zbl 1390.76831)

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##### References:

[1] | Vilela de Abreu, R.; Jansson, N.; Hoffman, J., Adaptive computation of aeroacoustic sources for a rudimentary landing gear, Int J Numer Meth Fluids, 74, 6, 406-421, (2014) |

[2] | Spalart, P. R.; Mejia, K., Analysis of experimental and numerical studies of the rudimentary landing gear, Proceedings for 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Orlando, Florida, (2011) |

[3] | Schumann, U., Subgrid-scale model for finite difference simulation of turbulent flows in plane channels and annuli, J Comput Phys, 18, 376-404, (1975) · Zbl 0403.76049 |

[4] | Casalino, D., Pdcc-nlg, Proceedings for the Second Benchmark problems for Airframe Noise Computations (BANC-II), Colorado Springs, CO, 7-8, (June 2012) |

[5] | Ueno, Y., Results of ddes with layered grid (using khis modified “cflow”), Proceedings for the Second Benchmark problems for Airframe Noise Computations (BANC-II), Colorado Springs, CO, 7-8, (June 2012) |

[6] | Vatsa, V. N.; Khorrami, M.; Lockard, D., Application of adaptive gridding in fun3d for simulation of flow over a nose landing gear, Proceedings for the Second Benchmark problems for Airframe Noise Computations (BANC-II), Colorado Springs, CO, 7-8, (June 2012) |

[7] | Hoffman, J., Computation of mean drag for bluff body problems using adaptive dns/LES, SIAM J Sci Comput, 27(1), 184-207, (2005) · Zbl 1149.65318 |

[8] | Hoffman, J., Adaptive simulation of the turbulent flow past a sphere, J Fluid Mech, 568, 77-88, (2006) · Zbl 1177.76157 |

[9] | Hoffman, J.; Johnson, C., A new approach to computational turbulence modeling, Comput Methods Appl Mech Engrg, 195, 2865-2880, (2006) · Zbl 1176.76065 |

[10] | Hoffman, J., Efficient computation of mean drag for the subcritical flow past a circular cylinder using general Galerkin g2, Int J Numer Meth Fluids, 59(11), 1241-1258, (2009) · Zbl 1409.76062 |

[11] | Neuhart, D. H.; Khorrami, M. R.; Choudhari, M. M., Aerodynamics of a gulfstream g550 nose landing gear model, Proceedings for the 15th AIAA/CEAS Aeroacoustics Conference (30th AIAA Aeroacoustics Conference), Miami, FL, (May 2009) |

[12] | Fidkowski, K. J.; Darmofal, D. L., Review of output-based error estimation and mesh adaptation in computational fluid dynamics, AIAA Journal, 49, 4, 673-694, (2011) |

[13] | Jansson, N.; Hoffman, J.; Nazarov, M., Adaptive simulation of turbulent flow past a full car model, Proc SC’11 State of the practice reports, (2011) |

[14] | Lighthill, M. J., On sound generated aerodynamically, Proc R Soc Lond A, 211, 564-587, (1952) · Zbl 0049.25905 |

[15] | Vilela de Abreu, R.; Jansson, N.; Hoffman, J., Adaptive computation of aeroacoustic sources for a rudimentary landing gear using lighthill’s analogy, Proceedings for the 17th AIAA/CEAS Aeroacoustics Conference (32nd AIAA Aeroacoustics Conference), Portland, OR, (June 2011) |

[16] | Spalart, P. R.; Shur, M. L.; Strelets, M. K.; Travin, A. K., Initial noise predictions for rudimentary landing gear, J Sound and Vib, 330, 17, 4180-4195, (2011) |

[17] | Spalart, P. R.; Shur, M. L.; Strelets, M. K.; Travin, A. K., Sensitivity of landing-gear noise predictions by large-eddy simulation to numerics and resolution, Proceedings for the 50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Nashville, Tennessee, (January 2012) |

[18] | Hoffman, J.; Johnson, C., Computational Turbulent Incompressible Flow, Applied Mathematics: Body and Soul, vol. 4, (2007), Springer |

[19] | Hoffman, J.; Jansson, N., A Computational Study of Turbulent Flow Separation for a Circular Cylinder Using Skin Friction Boundary Conditions, Ercoftac, Vol. 16, (2010), Springer |

[20] | Hoffman, J.; Johnson, C., Resolution of d’alembert’s paradox, J Math Fluid Mech, 10, (December 2008) |

[21] | Hoffman, J.; Jansson, J.; Vilela de Abreu, R.; Degirmenci, N. C.; Jansson, N.; Müller, K., Unicorn: parallel adaptive finite element simulation of turbulent flow and fluid-structure interaction for deforming domains and complex geometry, Comput Fluids, (2012) |

[22] | Hoffman J, Jansson J, Nazarov M, Jansson N. Unicorn: a unified continuum mechanics solver. In: Automated Scientific Computing. Springer 2011. |

[23] | Hoffman J, Jansson J, Jansson N, Johnson C, Vilela de Abreu R. Turbulent flow and fluid-structure interaction. In: Automated Solution of Differential Equations by the Finite Element Method; ch. 28. Springer 2012. |

[24] | FEniCS, Fenics project, (2003) |

[25] | Vatsa, V. N.; Lockard, D. P.; Khorrami, M. R., Fun3d solutions for nose landing gear, Proceedings for the First Benchmark problems for Airframe Noise Computations (BANC-I), Stockholm, Sweden, (June 2010) |

[26] | King, A.; Arobone, E.; Baden, S. B.; Sarkar, S., The saaz framework for turbulent flow queries, Proceedings for the 7th IEEE International Conference on e-Science, Stockholm, Sweden, (December 2011) |

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