Design and Motion Performance Analysis of Turbulent AUV Measuring Platform

Yunli Nie; Dalei Song; Zhenyu Wang; Yan Huang; Hua Yang

doi:10.3390/s22020460

Design and Motion Performance Analysis of Turbulent AUV Measuring Platform

Sensors (Basel). 2022 Jan 8;22(2):460. doi: 10.3390/s22020460.

Authors

Yunli Nie¹, Dalei Song^{2

3}, Zhenyu Wang⁴, Yan Huang⁴, Hua Yang⁵

Affiliations

¹ College of Ocean Science and Engineering, Shandong University of Science and Technology, No. 579 Qianwangang Rd., Qingdao 266590, China.
² College of Engineering, Ocean University of China, No. 238 Songling Rd., Qingdao 266100, China.
³ Institute for Advanced Ocean Study, Ocean University of China, No. 238 Songling Rd., Qingdao 266100, China.
⁴ Shenyang Institute of Automation Chinese Academy of Sciences, Shenyang 110016, China.
⁵ College of Information Science and Engineering, Ocean University of China, No. 238 Songling Rd., Qingdao 266100, China.

Abstract

The use of a multi-functional autonomous underwater vehicle (AUV) as a platform for making turbulence measurements in the ocean is developed. The layout optimization of the turbulence package and platform motion performance are limitation problems in turbulent AUV design. In this study, the computational fluid dynamics (CFD) method has been used to determine the optimized layout position and distance of the shear probe integrated into an AUV. When placed 0.8 D ahead of the AUV nose along the axis, the shear probe is not influenced by flow distortion and can contact the water body first. To analyze the motion of the turbulence AUV, the dynamic model of turbulence AUV for planar flight is obtained. Then, the mathematical equations of speed and angle of attack under steady-state motion have also been obtained. By calculating the hydrodynamic coefficients of the turbulence AUV and given system parameters, the simulation analysis has been conducted. The simulation results demonstrated that the speed of turbulent AUV is 0.5-1 m/s, and the maximum angle of attack is less than 6.5°, which meets the observation requirements of the shear probe. In addition, turbulence AUV conducted a series of sea-trials in the northern South China Sea to illustrate the validity of the design and measurement. Two continuous profiles (1000 m) with a horizontal distance of 10 km were completed, and numerous high-quality spatiotemporal turbulence data were obtained. These profiles demonstrate the superior flight performance of turbulence AUV. Analysis shows that the measured data are of high quality, with the shear spectra being in very good agreement with the Nasmyth spectrum. Dissipation rates are consistent with background shear. When shear velocity is weak, the measurement of dissipation rate is 10^-10 W Kg^-1. All indications are that the turbulence AUV is suitable for long-term, contiguous ocean microstructure measurements, which will provide data needed to understand the temporal and spatial variability of the turbulent processes in the oceans.

Keywords: AUV; CFD; motion simulation; sea-trials; sensor integration; turbulence measurements.

Abstract

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