Flow Testing of a Digital Sonic Anemometer for Martian and Stratospheric Environments

TY - GEN

T1 - Flow Testing of a Digital Sonic Anemometer for Martian and Stratospheric Environments

AU - White, Robert D.

AU - Chaudhary, Rishabh

AU - Cheng, Tim J.

AU - Fisher, Benjamin

AU - Huckaby, Julia

AU - Banfield, Don

AU - Colaprete, Anthony

AU - Cook, Amanda

AU - Dave, Arwen

AU - Jha, Vandana

AU - Rademacher, Abraham

AU - Shimada, Jared

AU - White, Bruce

AU - Yoder, Christopher

AU - Ian Neeson, Neeson

AU - Merrison, Jonathan P.

AU - Iversen, Jens Jacob

N1 - Publisher Copyright: © 2024, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

PY - 2024

Y1 - 2024

N2 - Reported here are the results of wind tunnel tests for a digital sonic anemometer targeted at the Martian surface and Earth’s stratosphere. The anemometer system uses ultrasound in the 35 to 55 kHz band to measure three-dimensional wind velocity and the speed of sound. The instrument has been designed to operate in low pressure environments, specifically at 6 mbar in CO2 of relevance to the surface of Mars, and dry air at pressures as low as 2 mbar of relevance to Earth’s stratosphere at altitudes up to 42 km. Advantages to the system include high accuracy and resolution, high update rate, and low power consumption. The current prototype produces 4.2 three-dimensional wind speed measurements per second and has a “no windflow” RMS noise level of 1.4 cm/s in 6 mbar CO2 and 2.5 cm/s in 4 mbar air. The sensor head has an acoustic path length of 19 cm and a total mass of 400g. The primary challenge that had to be overcome in designing the instrument was operation in low pressure environments with the correspondingly low acoustic signal level. Electronics had to be carefully designed to avoid electrical and structural cross-talk, and to reduce noise. Secondary challenges for calibration include transducer pressure and temperature sensitivity, and self wind-shadowing produced by the wake of the flow over the sensor head. In this paper we report on system architecture and test results in the Mars Simulation Wind Tunnel at the University of Aarhus, Denmark. Testing was performed both in 6 mbar dry CO2 and in 4 or 11 mbar dry air at flow speeds from 0 to 11 m/s in various orientations at temperatures between 10 oC and 23 oC. The system produced measurements in three dimensions that agreed well with a laser doppler anemometry system, providing wind speeds that were within expectations. Differential phase measurements and cross-correlation techniques using linear chirps and multi-tone windowed bursts were explored. Both methods perform comparably.

AB - Reported here are the results of wind tunnel tests for a digital sonic anemometer targeted at the Martian surface and Earth’s stratosphere. The anemometer system uses ultrasound in the 35 to 55 kHz band to measure three-dimensional wind velocity and the speed of sound. The instrument has been designed to operate in low pressure environments, specifically at 6 mbar in CO2 of relevance to the surface of Mars, and dry air at pressures as low as 2 mbar of relevance to Earth’s stratosphere at altitudes up to 42 km. Advantages to the system include high accuracy and resolution, high update rate, and low power consumption. The current prototype produces 4.2 three-dimensional wind speed measurements per second and has a “no windflow” RMS noise level of 1.4 cm/s in 6 mbar CO2 and 2.5 cm/s in 4 mbar air. The sensor head has an acoustic path length of 19 cm and a total mass of 400g. The primary challenge that had to be overcome in designing the instrument was operation in low pressure environments with the correspondingly low acoustic signal level. Electronics had to be carefully designed to avoid electrical and structural cross-talk, and to reduce noise. Secondary challenges for calibration include transducer pressure and temperature sensitivity, and self wind-shadowing produced by the wake of the flow over the sensor head. In this paper we report on system architecture and test results in the Mars Simulation Wind Tunnel at the University of Aarhus, Denmark. Testing was performed both in 6 mbar dry CO2 and in 4 or 11 mbar dry air at flow speeds from 0 to 11 m/s in various orientations at temperatures between 10 oC and 23 oC. The system produced measurements in three dimensions that agreed well with a laser doppler anemometry system, providing wind speeds that were within expectations. Differential phase measurements and cross-correlation techniques using linear chirps and multi-tone windowed bursts were explored. Both methods perform comparably.

UR - http://www.scopus.com/inward/record.url?scp=85203173820&partnerID=8YFLogxK

U2 - 10.2514/6.2024-3933

DO - 10.2514/6.2024-3933

M3 - Article in proceedings

AN - SCOPUS:85203173820

SN - 9781624107160

BT - AIAA Aviation Forum and ASCEND, 2024

PB - American Institute of Aeronautics and Astronautics Inc. (AIAA)

CY - Las Vegas

T2 - AIAA Aviation Forum and ASCEND, 2024

Y2 - 29 July 2024 through 2 August 2024

ER -