Effects of vorticity field traces of an ovoid object in a uniform water body on the infrared characteristics of the water surface

• Published in: Ocean engineering Vol. 308; p. 118229
• Main Authors: Wang, Cheng-An, Li, Yu, Wang, Xin-Sheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.09.2024
• Subjects: Hot skin layer; Infrared signature; Particle image velocimetry; Underwater vehicle; Vorticity wake; Hot skin layer; Particle image velocimetry; Underwater vehicle; Vorticity wake; Infrared signature
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2024.118229

Underwater movement of objects can generate hydrodynamic and thermal wakes. Inverting these wake signals can provide information about underwater vehicles, making it essential to understand the characteristics and laws of those hydrodynamic and thermal signals. This study experimentally explored the evolution of vorticity wake of underwater vehicles in a uniform water body and their influence on the infrared characteristics of surface wakes. First, we analyzed the background noise of the water surface flow field and then studied the evolution of the vorticity wake, the coupling relationship between the thermal and hydrodynamic signals of the wake, and the influence of depth and speed on the intensity of the wake signal. The experimental results showed that the water above the vehicle has a strong suppression of vorticity. When the vorticity owes sufficient intensity and duration, the vortical structure is found to be the primary cause of the thermal signal, which destroys the hot skin layer on the water surface. The superposition of waves generated by the ovoid body leads to a non-monotonic variation in the intensity of the wake signal with motion speed. The findings of this study can provide experimental support for infrared detection of underwater vehicles. •The evolution laws of vortex wake generated by underwater vehicle were studied experimentally.•The coupling relationship between the vortex and thermal wake was studied experimentally.•The variation laws of the vortex and thermal wakes with diving depth and speed of ovoid body were investigated.•The impact of wave superposition on wake signals was investigated.