X-38 Experimental Aerothermodynamics

Horvath, Thomas J.; Berry, Scott A.; Merski, N. Ronald; Fitzgerald, Steve

doi:10.2514/1.9198

Cited by 35 publications

(9 citation statements)

References 26 publications

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“…With temperature maps acquired at different times during the run, global heat transfer images can be computed, assuming an one-dimensional semi-infinite heat conduction model. Scaled hypersonic models of X-33 [97], X-34 [98], X-38 [99, 100] and X-43 [101] have all been tested in wind tunnels using phosphor thermometry at Mach 6 and 10 in air, and some have been tested at Mach 20 in Helium [97]. Further details can be found in the references.…”

Section: Survey Of Recent Applications Using Thermographic Phosphormentioning

confidence: 99%

“…This is somewhat similar to that of thin films. Repeatability was found to be generally better, around 4% [100]. Merski [102] notes that the total uncertainties associated with the phosphor technique is shown to be approximately 7–10% in NASA's 31-Inch Mach 10 Tunnel and 8–10% in the 20-Inch Mach 6 Tunnel.…”

Section: Survey Of Recent Applications Using Thermographic Phosphormentioning

confidence: 99%

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Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications

Khalid

Kontis

2008

Sensors

336

172

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This paper reviews the state of phosphor thermometry, focusing on developments in the past 15 years. The fundamental principles and theory are presented, and the various spectral and temporal modes, including the lifetime decay, rise time and intensity ratio, are discussed. The entire phosphor measurement system, including relative advantages to conventional methods, choice of phosphors, bonding techniques, excitation sources and emission detection, is reviewed. Special attention is given to issues that may arise at high temperatures. A number of recent developments and applications are surveyed, with examples including: measurements in engines, hypersonic wind tunnel experiments, pyrolysis studies and droplet/spray/gas temperature determination. They show the technique is flexible and successful in measuring temperatures where conventional methods may prove to be unsuitable.

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Section: Survey Of Recent Applications Using Thermographic Phosphormentioning

confidence: 99%

Section: Survey Of Recent Applications Using Thermographic Phosphormentioning

confidence: 99%

Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications

Khalid

Kontis

2008

Sensors

336

172

View full text Add to dashboard Cite

show abstract

“…The idea of thermographic phosphors for temperature measurements dates back to 1938 [1], and has seen a wide range of application areas since then, ranging from turbo-machinery [2][3][4][5], pyrolysis [6][7][8], supersonic [9], hypersonic and space re-entry studies [10][11][12]. Khalid and Kontis [13] recently reviewed developments in the past 15 years and provided a good theoretical background to phosphor thermometry.…”

Section: Introductionmentioning

confidence: 99%

Progress towards absolute intensity measurements of emissions from high temperature thermographic phosphors

Khalid

Kontis

2011

Journal of Luminescence

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“…One such optical acquisition method is two-color relative-intensity phosphor thermography 48,49,50 which has been utilized in several aeroheating tests conducted in the hypersonic wind tunnels of NASA LaRC 10, 51,52 . The process surrounding this global technique is shown in Fig.…”

Section: Test Techniquementioning

confidence: 99%

Shuttle Damage/Repair from the Perspective of Hypersonic Boundary Layer Transition - Experimental Results

Horvath

Berry

Merski

et al. 2006

9th AIAA/ASME Joint Thermophysics and Heat Transfer Conference

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An overview is provided of the experimental wind tunnel program conducted at the NASA Langley Research Center Aerothermodynamics Laboratory in support of an agency-wide effort to prepare the Shuttle Orbiter for Return-to-Flight. The effect of an isolated protuberance and an isolated rectangular cavity on hypersonic boundary layer transition onset on the windward surface of the Shuttle Orbiter has been experimentally characterized. These experimental studies were initiated to provide a protuberance and cavity effects database for developing hypersonic transition criteria to support on-orbit disposition of thermal protection system damage or repair. In addition, a synergistic experimental investigation was undertaken to assess the impact of an isolated mass-flow entrainment source (simulating pyrolysis/outgassing from a proposed tile repair material) on boundary layer transition. A brief review of the relevant literature regarding hypersonic boundary layer transition induced from cavities and localized mass addition from ablation is presented. Boundary layer transition results were obtained using 0.0075-scale Orbiter models with simulated tile damage (rectangular cavities) of varying length, width, and depth and simulated tile damage or repair (protuberances) of varying height. Cavity and mass addition effects were assessed at a fixed location (x/L = 0.3) along the model centerline in a region of near zero pressure gradient. Cavity length-to-depth ratio was systematically varied from 2.5 to 17.7 and length-to-width ratio of 1 to 8.5. Cavity depth-to-local boundary layer thickness ranged from 0.5 to 4.8. Protuberances were located at several sites along the centerline and port/starboard attachment lines along the chine and wing leading edge. Protuberance height-to-boundary layer thickness was varied from approximately 0.2 to 1.1. Global heat transfer images and heating distributions of the Orbiter windward surface using phosphor thermography were used to infer the state of the boundary layer (laminar, transitional, or turbulent). Test parametrics include angles-of-attack of 30 deg and 40 deg, sideslip angle of 0 deg, freestream Reynolds numbers from 0.02x10 6 to 7.3x10 6 per foot, edge-to-wall temperature ratio from 0.4 to 0.8, and normal shock density ratios of approximately 5.3, 6.0, and 12 in Mach 6 air, Mach 10 air, and Mach 6 CF 4 , respectively. Testing to simulate the effects of ablation from a proposed tile repair concept indicated that transition was not a concern. The experimental protuberance and cavity databases highlighted in this report were used to formulate boundary layer transition correlations that were an integral part of an analytical process to disposition observed Orbiter TPS damage during STS-114.

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X-38 Experimental Aerothermodynamics

Abstract: The

Cited by 35 publications

References 26 publications

Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications

Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications

Progress towards absolute intensity measurements of emissions from high temperature thermographic phosphors

Shuttle Damage/Repair from the Perspective of Hypersonic Boundary Layer Transition - Experimental Results

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