On the use of general elements in fluid dynamics simulations

Chalasani, Satish; Senguttuvan, V.; Thompson, David S.; Luke, Edward A.

doi:10.1002/cnm.1017

Cited by 31 publications

(10 citation statements)

References 28 publications

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“…10 Loci/CHEM numerical models have been demonstrated to be at least second order accurate in space and time through rigorous verification using the Method of Manufactured Solutions (MMS). 11 Loci/CHEM supports adaptive mesh refinement, 12 simulations of complex equations-of-state including cryogenic fluids, 13 multiphase simulations of dispersed liquid and solid particulates using both Lagrangian and Eulerian approaches, 14 conjugate heat transfer through solids, 15 fluid structure interaction modeling, 16 and non-gray radiative heat transfer associated with both, gas and particulate phases. 17 The Loci/CHEM solver infrastructure supports overset meshes for efficient simulation of flows over complex geometry and moving boundary problems.…”

Section: Overview Of Loci Framework and Loci/chem Flow Solvermentioning

confidence: 99%

Towards a Predictive Capability for Multiple-Body Proximate-Flight in High-Speed Air-Delivered Systems

Harris

Liever

Luke

et al. 2012

42nd AIAA Fluid Dynamics Conference and Exhibit

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Multiple-body high-speed air-delivered systems are subjected to a complex flow environment characterized by inter-body collisions, large interference pressures, and strong moving shock systems. These unique physics are prevalent in the strong interaction phase early in the projectile deployment, and have a first-order effect on the resulting projectile dispersion pattern. Since classical engineering-level simulation methods cannot predict these patterns with adequate confidence, highfidelity methods that include all relevant physics are necessary to accurately predict the projectile trajectories at the conclusion of the interference-dominated flight phase. Newly developed capabilities in the Loci/CHEM framework have enabled multiple-body proximate flight simulations including high-fidelity aerodynamics with six degrees of freedom modeling and collision response that are well-suited for simulation of large numbers of projectiles. Unlike many approaches for moving body simulation, the approach presented here utilizes unstructured overset grids with fully automatic grid assembly and no ancillary preprocessing requirements beyond those necessary for static body simulation. The solution methodology and collision modeling capabilities are described in detail. Results are presented for supersonic air-delivered systems with dozens of projectiles in close-proximity released from a carrier vehicle under several different deployment configurations. The results demonstrate the effectiveness of the developed capabilities for simulation of high-speed proximate-flight among many projectiles including strong aerodynamic interference effects and frequent inter-body collisions.

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Section: Overview Of Loci Framework and Loci/chem Flow Solvermentioning

confidence: 99%

Towards a Predictive Capability for Multiple-Body Proximate-Flight in High-Speed Air-Delivered Systems

Harris

Liever

Luke

et al. 2012

42nd AIAA Fluid Dynamics Conference and Exhibit

View full text Add to dashboard Cite

show abstract

“…In addition, the algorithms have been extended to Loci/CHEM numerical models have been demonstrated to be at least second order accurate in space and time through rigorous verification using the Method of Manufactured Solutions (MMS). 10 Loci/CHEM supports adaptive mesh refinement, 11 simulations of complex equations-of-state including cryogenic fluids, 12 multiphase simulations of dispersed liquid and solid particulates using both Lagrangian and Eulerian approaches, 13 conjugate heat transfer through solids, 14 fluid structure interaction modeling, 15 and non-gray radiative heat transfer associated with both, gas and particulate phases. 16 For complex geometry and object motion problems, the Loci/CHEM solver infrastructure supports overset meshes.…”

Section: Overview Of Loci Framework and Loci/chem Flow Solvermentioning

confidence: 99%

Development of Modeling Capabilities for Launch Pad Acoustics and Ignition Transient Environment Prediction

West

Strutzenberg

Putnam³

et al. 2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

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This paper presents the development effort to establish modeling capabilities for launch vehicle liftoff acoustics and ignition transient environment predictions. Peak acoustic loads experienced by the launch vehicle occur during liftoff with strong interaction between the vehicle and the launch facility. Acoustic prediction engineering tools based on empirical models are of limited value in efforts to proactively design and optimize launch vehicles and launch facility configurations for liftoff acoustics. Modeling approaches are needed that capture the important details of the plume flow environment including the ignition transient, identify the noise generation sources and allow assessment of the effects of launch pad geometric details and acoustic mitigation measures such as water injection. This paper will present a status of the CFD tools developed by the Marshall Space Flight Center (MSFC) Fluid Dynamics Branch featuring relevant advanced multi-physics modeling capabilities and related efforts to establish a hybrid acoustic environment modeling capability combining CFD with a Boundary Element Method (BEM) acoustic field propagation model.The CFD analysis software program utilized at the MSFC Fluid Dynamics Branch is Loci/CHEM. Loci is a highly scalable computational framework with automatic parallelization for computational field simulations [1,2]. Loci was developed at Mississippi State University by Dr. Ed Luke. Loci/CHEM is a density-based Navier-Stokes solver [3] implemented in the Loci framework with the following features:Generalized unstructured grids RANS, URANS, DES, Hybrid RANS/LES turbulence modeling Eulerian multiphase models for particulates and droplets Lagrangian multiphase models for particulates and droplets with particle vaporization, condensation, combustion Real fluids EOS for cryogenic injection and combustion analysis Non-gray radiation transport models (particle and gas phase radiation) Solution adaptive mesh refinement with various error estimators available Mesh deformation for fluid-structure deformation and fuel burn-back surface Overset moving body with prescribed motion and 6-DOF Body Collision 6-DOF modeling Loci/CHEM has been extensively verified using the Method of Manufactured Solutions (MMS) Technique. The numerical algorithms are verified to be 2 nd order space and 2 nd order time accurate, but do not feature low dispersion and low dissipation algorithms at this point of development. Production simulations are routinely executed with up to 300M mesh cells on more than 3000 processors on the NASA NAS Pleiades supercomputer. The advances in CFD simulation capability and fidelity in the Fluid Dynamics Branch at MSFC have resulted in CFD modeling of complete launch vehicles with multiple plumes interacting with detailed launch pad geometric models ( Figure 1). These analyses have become invaluable in defining liftoff environments for Shuttle and future NASA heavy lift launch vehicle designs. Simulations with these tools are capable of capturing the sources of acoustic waves o...

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“…We employ the isotropic mesh refinement strategy described in Chalasani et al [9]. In this approach, an n-sided face is subdivided into n faces by inserting a node at the centroid of the face and connecting it to the mid point of each edge.…”

Section: Adaptive Mesh Refinementmentioning

confidence: 99%

“…In the current effort, regions near the core line, near the extent surface, or inside the extent surface can be identified and employed to mark mesh nodes located in these regions. Once the nodes are marked, the strategy described in Chalasani et al [9] is employed to refine the mesh in the specified regions. The flow solver we use is the Loci/CHEM code [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Feature‐based adaptive mesh refinement for wingtip vortices

Kasmai

Thompson

Luke

et al. 2011

Numerical Methods in Fluids

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SUMMARYFeature-based solution-adaptive mesh refinement is an attractive strategy when it is known a priori that the resolution of certain key features is critical to achieving the objectives of a simulation. In this paper, we apply vortex characterization techniques, which are typically employed to visualize vortices, to identify regions of the computational domain for mesh refinement. We investigate different refinement strategies that are facilitated by these vortex characterization techniques to simulate the flow past a wing in a wind tunnel. Our results, which we compare with experimental data, indicate that it is necessary to refine the region within and near the vortex extent surface to obtain an accurate prediction. Application of the identified mesh refinement strategy also produced observed improvement in the results predicted for a spinning missile with deflected canards.

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On the use of general elements in fluid dynamics simulations

Cited by 31 publications

References 28 publications

Towards a Predictive Capability for Multiple-Body Proximate-Flight in High-Speed Air-Delivered Systems

Towards a Predictive Capability for Multiple-Body Proximate-Flight in High-Speed Air-Delivered Systems

Development of Modeling Capabilities for Launch Pad Acoustics and Ignition Transient Environment Prediction

Feature‐based adaptive mesh refinement for wingtip vortices

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