Heating analysis for a Lunar Transfer Vehicle at near-equilibrium flow conditions

A seven-species hypersonic flow solver that independently tracks vibrational energies of diatomic species has been coupled with SPRADIAN for the purposes of developing a spectrally accurate coupled radiation / flowfield solution. Results are presented for the FIRE-II and RAM-C geometries, and compared to experiment results where available. Shortfalls of the method are identified, along with avenues of further research. It is desired to eventually develop the capability to use a complete air chemistry set with ablation byproducts for a total assessment of the radiation environment around an arbitrary shape.

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“…al. 3 was used. Grid adaptation was executed multiple time during the course of a computational run.…”

Section: Coupling Methodologymentioning

confidence: 99%

Development of Coupled Flowfield - Radiation Solution Methods in Ablative Environments

Jerey¹,

Komives²,

Greendyke³

2009

47th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…Requirements for a grid-converged solution are problem dependent. Following LAURA best practices and based on previous grid convergence studies on closely related problems [16][17][18][19][20][21][22] we would expect a maximum change in surface heating distribution on the forebody of less than 8% (usually lower for attached flow). Risk in the migration from LAURA to FUN3D has been mitigated through extensive re-use of modules currently in LAURA.…”

Section: Functional Equivalence Overviewmentioning

confidence: 99%

Functional Equivalence Acceptance Testing of FUN3D for Entry, Descent, and Landing Applications

Gnoffo

Wood

Kleb

et al. 2013

21st AIAA Computational Fluid Dynamics Conference

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The functional equivalence of the unstructured grid code FUN3D to the the structured grid code LAURA (Langley Aerothermodynamic Upwind Relaxation Algorithm) is documented for applications of interest to the Entry, Descent, and Landing (EDL) community. Examples from an existing suite of regression tests are used to demonstrate the functional equivalence, encompassing various thermochemical models and vehicle configurations. Algorithm modifications required for the node-based unstructured grid code (FUN3D) to reproduce functionality of the cell-centered structured code (LAURA) are also documented. Challenges associated with computation on tetrahedral grids versus computation on structured-grid derived hexahedral systems are discussed.

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“…The normal distribution is dened with a cell Reynolds number equal to 1 at the surface and a stretching function in which roughly half the available cells are assigned to the boundary layer and the remainder are equally spaced across the shock layer. 34 Normal grid distribution is periodically updated as the solution evolves. Some grid renement studies are implemented using an 81 x 41 point surface grid.…”

Section: Computational Gridmentioning

confidence: 99%

Effects of sonic line transition on aerothermodynamics of the Mars Pathfinder Probe

Peter

James²,

Robert³

et al. 1995

13th Applied Aerodynamics Conference

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Floweld solutions over the Mars Pathnder Probe spanning the trajectory through the Martian atmosphere at angles of attack from 0 to 11 degrees are obtained. Aerodynamic coecients derived from these solutions reveal two regions where the derivative of pitching moment with respect to angle of attack is positive at small angles of attack. The behavior is associated with the transition of the sonic line location between the blunted nose and the windside shoulder of the 70 degree half-angle cone in a gas with a low eective ratio of specic heats. The transition rst occurs as the shock layer gas chemistry evolves from highly nonequilibrium to near equilibrium, above approximately 6.5 km/s and 40 km altitude, causing the eective specic heat ratio to decrease. The transition next occurs in an equilibrium ow regime as velocities decrease through 3.5 km/s and the specic heat ratio increases again with decreasing enthalpy. The eects of the expansion over the shoulder into the wake are more strongly felt on the fustrum when the sonic line sits on the shoulder. The transition also produces a counter-intuitive trend in which windside heating levels decrease with increasing angle of attack resulting from an increase in the effective radius of curvature. Six-degree-of-freedom trajectory analyses utilizing the computed aerodynamic coecients predict a moderate, 3 to 4 degree increase in total angle of attack as the probe, spinning at approximately 2 revolutions per minute, passes through these regions.

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Heating analysis for a Lunar Transfer Vehicle at near-equilibrium flow conditions

Cited by 19 publications

References 6 publications

Development of Coupled Flowfield - Radiation Solution Methods in Ablative Environments

Development of Coupled Flowfield - Radiation Solution Methods in Ablative Environments

Functional Equivalence Acceptance Testing of FUN3D for Entry, Descent, and Landing Applications

Effects of sonic line transition on aerothermodynamics of the Mars Pathfinder Probe

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