Surface Catalyzed Reaction Efficiencies in Oxygen Plasmas from Laser-Induced Fluorescence Measurements

Fletcher, Douglas G.; Meyers, Jason M.

doi:10.2514/1.t4923

Cited by 26 publications

(11 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other efforts have been devoted to develop alternative methods using subtraction of the convective contribution, obtained from a correlation, from the total measured heat flux [16] or near-surface diagnostic techniques [17].…”

Section: Enthalpy Rebuilding and Catalytic Property Determinationmentioning

confidence: 99%

Quantification of uncertainty on the catalytic property of reusable thermal protection materials from high enthalpy experiments

Sanson

Villedieu

Panerai

et al. 2017

Experimental Thermal and Fluid Science

View full text Add to dashboard Cite

An accurate determination of the catalytic property of thermal protection materials is crucial to design reusable atmospheric entry vehicles. This property is determined by combining experimental measurements and simulations of the reactive boundary layer near the material surface. The inductively-driven Plasmatron facility at the von Karman Institute for Fluid Dynamics provides a test environment to analyze gas-surface interactions under effective hypersonic conditions. In this study, we develop an uncertainty quantification methodology to rebuild values of the gas enthalpy and material catalytic property from Plasmatron experiments. A non-intrusive spectral projection method is coupled with an in-house boundarylayer solver, to propagate uncertainties and provide error bars on the rebuilt gas enthalpy and material catalytic property, as well as to determine which uncertainties have the largest contribution to the outputs of the experiments. We show * Corresponding author. that the uncertainties computed with the methodology developed are significantly reduced compared to those determined using a more conservative engineering approach adopted in the analysis of previous experimental campaigns.

show abstract

Section: Enthalpy Rebuilding and Catalytic Property Determinationmentioning

confidence: 99%

Quantification of uncertainty on the catalytic property of reusable thermal protection materials from high enthalpy experiments

Sanson

Villedieu

Panerai

et al. 2017

Experimental Thermal and Fluid Science

View full text Add to dashboard Cite

show abstract

“…The laser linewidth ∆λ L is determined to be 2.26 pm in this study by fitting a spectral model of the transition line shape at the known temperature of 824 K. The relative number density was obtained from the spectral integrals of the TALIF signals. Taking into account the population of the J = 2 level, the number density was proportional to [16]…”

Section: Laboratory Evaluation Methodsmentioning

confidence: 99%

“…It can be seen from figure 4(a) that the diameter of the fluorescence is close to 0.15 mm. The fluorescence beam diameter is slightly larger than the 0.1-mm measurement step size, but this will not significantly degrade the spatial resolution, since the two-photon LIF signal is dominated by the central portion of the Gaussian laser intensity profile, as pointed out by Fletcher and Meyers [16]. The choice of y = 3.6mm was because the TALIF signals were consistent at this point as long as the plasma environment remained unchanged, regardless of the existence of the material specimen.…”

Section: Laboratory Evaluation Methodsmentioning

confidence: 99%

“…In this way, the accuracy of the results was highly influenced by the theoretical equations. More recently, Fletcher and his team [16,17] conducted LIF measurements in the UVM 30 kW ICP Torch Facility and proposed a mole fraction gradient theory to determine the catalytic coefficient. This theory took advantage of the relationships of the LIF signal to the atomic oxygen densities and temperatures, providing a direct determination method of the catalytic coefficient.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of atomic oxygen catalytic coefficient of ZrB₂–SiC by laser-induced fluorescence up to 1473 K

Meng¹,

Zeng²,

Jin³

et al. 2018

Meas. Sci. Technol.

View full text Add to dashboard Cite

The atomic oxygen catalytic coefficient, as a key parameter for evaluating the catalytic heat contribution of thermal protection materials, requires thorough and principled experimental studies. In this study, a laboratory-based catalytic coefficient evaluation method based on laser-induced fluorescence diagnosis in radiofrequency inductively coupled plasma and mole fraction gradient theory was investigated. Using this method, the atomic oxygen catalytic coefficients were determined for water-cooled copper, quartz of different temperatures, and, for the first time to our knowledge, ZrB2–SiC ceramics up to 1473 K. The validity of the proposed method is compared with the results from published studies using optical emission spectroscopy and laser-induced fluorescence methods.

show abstract

“…The temperature of the gas entering the test chamber is controlled through the electrical current to the coil where only a fraction of the supplied power is converted to thermal energy in the gas. Traditionally, using laser-induced fluorescence (LIF), critical flow parameters including translational temperature and species number densities can be measured at various points in the chamber [27,28]. These profiles can be used to calibrate the simulation conditions relative to the torch electrical current setting.…”

Section: Plasma Torch Experimentsmentioning

confidence: 99%

Evaluation of Computational Models for Electron Transpiration Cooling

et al. 2021

View full text Add to dashboard Cite

Recent developments in the world of hypersonic flight have brought increased attention to the thermal response of materials exposed to high-enthalpy gases. One promising concept is electron transpiration cooling (ETC) that provides the prospect of a passive heat removal mechanism, rivaling and possibly outperforming that of radiative cooling. In this work, non-equilibrium CFD simulations are performed to evaluate the possible roles of this cooling mode under high-enthalpy conditions obtainable in plasma torch ground-test facilities capable of long flow times. The work focuses on the test case of argon gas being heated to achieve enthalpies equivalent to post-shock conditions experienced by a vehicle flying through the atmosphere at hypersonic speed. Simulations are performed at a range of conditions and are used to calibrate direct comparisons between torch operating conditions and resulting flow properties. These comparisons highlight important modeling considerations for simulating long-duration, hot chamber tests. Simulation results correspond well with the experimental measurements of gas temperature, material surface temperature as well as measured current generated in the test article. Theoretical methods taking into consideration space charge limitations are presented and applied to provide design suggestions to boost the ETC effect in future experiments.

show abstract

Surface Catalyzed Reaction Efficiencies in Oxygen Plasmas from Laser-Induced Fluorescence Measurements

Cited by 26 publications

References 27 publications

Quantification of uncertainty on the catalytic property of reusable thermal protection materials from high enthalpy experiments

Quantification of uncertainty on the catalytic property of reusable thermal protection materials from high enthalpy experiments

Evaluation of atomic oxygen catalytic coefficient of ZrB₂–SiC by laser-induced fluorescence up to 1473 K

Evaluation of Computational Models for Electron Transpiration Cooling

Contact Info

Product

Resources

About

Surface Catalyzed Reaction Efficiencies in Oxygen Plasmas from Laser-Induced Fluorescence Measurements

Cited by 26 publications

References 27 publications

Quantification of uncertainty on the catalytic property of reusable thermal protection materials from high enthalpy experiments

Quantification of uncertainty on the catalytic property of reusable thermal protection materials from high enthalpy experiments

Evaluation of atomic oxygen catalytic coefficient of ZrB2–SiC by laser-induced fluorescence up to 1473 K

Evaluation of Computational Models for Electron Transpiration Cooling

Contact Info

Product

Resources

About

Evaluation of atomic oxygen catalytic coefficient of ZrB₂–SiC by laser-induced fluorescence up to 1473 K