Year: 2024
Type: article
Abstract: Vehicles travelling underwater experience drag and the frictional drag costs 60% of the total energy consumption. Using trapped air serving as a lubricant is a promising way to reduce drag. The trapped air plays a significant role in drag reduction, and most failures in drag reduction are related to instability, escape, and dissolution of the trapped air. In this work, discrete grooves are employed to trap air and reduce drag. Through the analysis of the trapped air stability, the groove length and width are believed to be the main factors that influence the air escape and instability, and thus they are limited in this work to avoid these problems. The air dissolution is inevitable. The effective way to mitigate the air dissolution is to deepen the groove depth. The groove depth in this work varies from 0.5 mm to 4 mm. The numerical simulation is employed to analyze the flow field, reveal the drag reduction mechanism, and optimize the groove length. The experimental measurements are conducted to verify our design. The result confirms our design that the discrete grooves successfully avoid air escape and instability, mitigate air dissolution, and reduce drag. This work is meaningful for underwater vehicles to travel with low energy consumption and high speed.
DOI: 10.3390/jmse12122224
Authors: You Nie, Ding Weng, Jiadao Wang
Institutions: State Key Laboratory of Tribology, Tsinghua University
Language: English
Subfield: Ocean Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,955
Award: G5665243559
OpenAlex ID: W4404993697