Entry, Descent and Landing Systems Analysis: Exploration Class Simulation Overview and Results

Dwyer-Cianciolo, Alicia M.; Davis, Jody L.; Shidner, Jeremy D.; Powell, Richard W.

doi:10.2514/6.2010-7970

Cited by 18 publications

(8 citation statements)

References 9 publications

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“…The size of this initial sample set, generated using Latin hypercube sampling, is taken as the size N t , given by Eq. (2) because this would be the minimum number of samples required to obtain a total-order expansion. Note that generating large sample sets of the uncertain parameters is not computationally expensive compared with the cost of evaluating the deterministic model.…”

Section: Uncertainty Quantification Methodologymentioning

confidence: 99%

“…With HIAD geometries this large, radiative heating can potentially be a significant fraction of the convective heating. Proposed insulated thermal protection system (TPS) materials [2,3] to protect the inflatable structure have relatively low heating limits (∼60 W∕cm 2 ), whereas flexible ablative TPS materials have higher heat flux limits (up to 115 W∕cm 2 for flexible silicone impregnated reusable ceramic ablators and up to 450 W∕cm 2 for flexible phenolic impregnated ceramic ablators). Accurate prediction of the radiative and convective heating of the HIAD surface with low-level heating requirements presents numerical simulation challenges.…”

Section: Introductionmentioning

confidence: 99%

“…Architecture-level assessments from entry, descent, and landing (EDL) systems analysis [1,2] and exploration feed-forward [3] (EFF) studies have established that a hypersonic inflatable aerodynamic decelerator (HIAD), coupled with supersonic retropropulsion and subsonic propulsive descent technologies, are enabling for safe and reliable landing at Mars. The inflatable technology has the capability to provide more options for planetary missions by allowing heavier and larger payloads and offering flexibility in landing site selection at higher altitudes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Uncertainty Analysis of Mars Entry Flows over a Hypersonic Inflatable Aerodynamic Decelerator

Brune

West

Hosder

et al. 2015

Journal of Spacecraft and Rockets

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A detailed uncertainty analysis for high-fidelity flowfield simulations over a fixed aeroshell of hypersonic inflatable aerodynamic decelerator scale for Mars entry is presented for fully laminar and turbulent flows at peak stagnationpoint heating conditions. This study implements a sparse-collocation approach based on stochastic expansions for efficient and accurate uncertainty quantification under a large number of uncertainty sources in the computational model. The convective and radiative heating and shear stress uncertainties are computed over the hypersonic inflatable aerodynamic decelerator surface and are shown to vary due to a small fraction of 65 flowfield and radiation modeling parameters considered in the uncertainty analysis. The main contributors to the convective heating uncertainty near the stagnation point are the CO 2 -CO 2 , CO 2 -O, and CO-O binary collision interactions, freestream density, and freestream velocity for both boundary-layer flows. In laminar flow, exothermic recombination reactions are more important at the shoulder. The main contributors to radiative heating at the nose and flank were the CO 2 dissociation rate and CO heavy-particle excitation rates, whereas the freestream density showed importance toward the shoulder. The CO 2 -CO 2 interaction and freestream velocity and density control the wall shear stress uncertainty. Nomenclature D = statistical variance N s = number of samples N t = number of terms in a total-order polynomial chaos expansion N TP = number of test points n = number of random dimensions p = order of polynomial expansion S e = percent absolute error S T = total Sobol index T e = test point error α = deterministic coefficient in polynomial chaos expansion α = generic uncertain function δ = truncation error μ e = mean error ξ = standard input random variable Ψ = random basis function Ω 1;1 = diffusion collision integral Ω 2;2 = viscosity collision integral

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Section: Uncertainty Quantification Methodologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Uncertainty Analysis of Mars Entry Flows over a Hypersonic Inflatable Aerodynamic Decelerator

Brune

West

Hosder

et al. 2015

Journal of Spacecraft and Rockets

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show abstract

“…= specific heat ratio θ = angle between geometry local surface normal and velocity vector θ 1 ,θ 2 = angles for Hammerhead geometry 1 st and 2 nd cones segments ρ ∞ = free stream density (kg/m 3 ) µ ∞ = free stream viscosity (kg/m/s)…”

Section: Nomenclaturementioning

confidence: 99%

Laminar, Transitional, and Turbulent Heating on Mid Lift-to-Drag Ratio Entry Vehicles

Hollis

Hollingsworth²

2013

Journal of Spacecraft and Rockets

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The boundary-layer transition characteristics and convective aeroheating levels on mid lift-to-drag ratio entry vehicle configurations have been studied through wind tunnel testing. Several configurations were investigated, including elliptically-blunted cylinders with both circular and elliptically-flattened cross sections, biconic geometries based on launch vehicle dual-use shrouds, and parametrically-optimized analytic geometries. Vehicles of this class have been proposed for high-mass Mars missions, such as sample return and crewed exploration, for which the conventional sphere-cone entry-vehicle geometries of previous Mars missions are insufficient. Testing was conducted at Mach 6 over a range of Reynolds numbers sufficient to generate laminar, transitional, and turbulent flow. Transition onset locations -both straight-line and cross-flow -and heating rates were obtained through global phosphor thermography. Supporting computations were performed to obtain heating rates for comparison with the data. Laminar data and predictions agreed to well within the experimental uncertainty. Fully-turbulent data and predictions also agreed well. However, in transitional flow regions, greater differences were observed. Additional aerodynamic performance data were also generated through Modified-Newtonian analyses of the geometries. Nomenclature

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“…Details of nominal reference trajectories and sensitivity studies for all architectures are presented elsewhere 3 . This paper focuses only on the simulation of the atmospheric entry portion of the trajectory.…”

Section: Tmentioning

confidence: 99%

Guidance and Control Algorithms for the Mars Entry, Descent and Landing Systems Analysis

Davis

CwyerCianciolo

Powell

et al. 2010

AIAA/AAS Astrodynamics Specialist Conference

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The purpose of the Mars Entry, Descent and Landing Systems Analysis (EDL-SA) study was to identify feasible technologies that will enable human exploration of Mars, specifically to deliver large payloads to the Martian surface. This paper focuses on the methods used to guide and control two of the contending technologies, a mid-lift-to-drag (L/D) rigid aeroshell and a hypersonic inflatable aerodynamic decelerator (HIAD), through the entry portion of the trajectory. The Program to Optimize Simulated Trajectories II (POST2) is used to simulate and analyze the trajectories of the contending technologies and guidance and control algorithms. Three guidance algorithms are discussed in this paper: EDL theoretical guidance, Numerical Predictor-Corrector (NPC) guidance and Analytical Predictor-Corrector (APC) guidance. EDL-SA also considered two forms of control: bank angle control, similar to that used by Apollo and the Space Shuttle, and a center-of-gravity (CG) offset control. This paper presents the performance comparison of these guidance algorithms and summarizes the results as they impact the technology recommendations for future study.

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Entry, Descent and Landing Systems Analysis: Exploration Class Simulation Overview and Results

Cited by 18 publications

References 9 publications

Uncertainty Analysis of Mars Entry Flows over a Hypersonic Inflatable Aerodynamic Decelerator

Uncertainty Analysis of Mars Entry Flows over a Hypersonic Inflatable Aerodynamic Decelerator

Laminar, Transitional, and Turbulent Heating on Mid Lift-to-Drag Ratio Entry Vehicles

Guidance and Control Algorithms for the Mars Entry, Descent and Landing Systems Analysis

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