TY - GEN
T1 - Millimeter Wave Interferometry for Ejecta Concentration Measurements in Plume-Surface Interactions
AU - Rasmont, Nicolas
AU - Al-Rashdan, Hussein T.
AU - Elliott, Gregory S.
AU - Rovey, Joshua L.
AU - Villafañe, Laura
N1 - Funding Information:
This work is supported by the National Aeronautics and Space Administration (NASA) under Grant No. 80NSSC20K0304 issued through the Early Stage Innovation Program. We acknowledge the contributions of Dr. Danehy, NASA Research Collaborator, through fruitful comments and discussions. We also thank Professor Bernhard from the Department of Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign (UIUC) for her helpful suggestions and remarks regarding the instrument concept, the Visualisation Laboratory at UIUC for their material support in the development of the particle shadow counting system, the UIUC Aerospace Machine Shop for manufacturing many pieces of experimental hardware, as well as Professor Panerai and graduate student Cutler Philippe for their guidance in the implementation of the microCT technique for particle size measurement.
Publisher Copyright:
© 2022, American Institute of Aeronautics and Astronautics Inc.. All rights reserved.
PY - 2022
Y1 - 2022
N2 - A novel method to measure the concentration of ejecta generated by the impingement of rocket plumes on granular surfaces is presented. This method is based on the principle of millimeter wave interferometry, using a fully-integrated frequency modulated continuous-wave 60-64 GHz radar to measure the path-integrated ejecta concentration between the radar itself and a reflector. The instrument is capable of quantitative measurements of high path-integrated ejecta concentrations up to 0.317 ± 0.133 vol%.m, one order of magnitude higher than state-of-the-art optical methods, at a repetition rate of 10 kHz and independently of the particle size distribution of the material. The interferometer was calibrated using a particle shadow counting technique for path-integrated concentrations up to 0.0223 ± 0.0008 vol%.m (0.280 ± 0.010 × 109 particles.m−2 ) and demonstrated on a reduced-scale plume-surface interaction experiment using a 6.5 N cold gas thruster impinging on a bed of regolith simulant under lunar (6.67 Pa) and martian (800 Pa) ambient pressures. A glass microsphere regolith simulant with a mean particle diameter of 105 μm and a standard deviation of 17μm was used for calibration and demonstration. The instrument performed nominally in both demonstrations conditions, measuring a maximum path-integrated ejecta concentration of 0.0419 ± 0.0170 vol%.m (0.527 ± 0.214 × 109 particles.m−2 ) in the lunar case and 0.131 ± 0.053 vol%.m (1.65 ± 0.67 × 109 particles.m−2 ) in the martian case.
AB - A novel method to measure the concentration of ejecta generated by the impingement of rocket plumes on granular surfaces is presented. This method is based on the principle of millimeter wave interferometry, using a fully-integrated frequency modulated continuous-wave 60-64 GHz radar to measure the path-integrated ejecta concentration between the radar itself and a reflector. The instrument is capable of quantitative measurements of high path-integrated ejecta concentrations up to 0.317 ± 0.133 vol%.m, one order of magnitude higher than state-of-the-art optical methods, at a repetition rate of 10 kHz and independently of the particle size distribution of the material. The interferometer was calibrated using a particle shadow counting technique for path-integrated concentrations up to 0.0223 ± 0.0008 vol%.m (0.280 ± 0.010 × 109 particles.m−2 ) and demonstrated on a reduced-scale plume-surface interaction experiment using a 6.5 N cold gas thruster impinging on a bed of regolith simulant under lunar (6.67 Pa) and martian (800 Pa) ambient pressures. A glass microsphere regolith simulant with a mean particle diameter of 105 μm and a standard deviation of 17μm was used for calibration and demonstration. The instrument performed nominally in both demonstrations conditions, measuring a maximum path-integrated ejecta concentration of 0.0419 ± 0.0170 vol%.m (0.527 ± 0.214 × 109 particles.m−2 ) in the lunar case and 0.131 ± 0.053 vol%.m (1.65 ± 0.67 × 109 particles.m−2 ) in the martian case.
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U2 - 10.2514/6.2022-2421
DO - 10.2514/6.2022-2421
M3 - Conference contribution
AN - SCOPUS:85123836535
SN - 9781624106316
T3 - AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2022
BT - AIAA SciTech Forum 2022
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2022
Y2 - 3 January 2022 through 7 January 2022
ER -