Combustion-enabled underwater vehicles (CUVs) in dynamic fluid environment

Underwater vehicles have opened a unique path to multifunctionality and environmental adaptability. However, inadequate studies have been conducted to investigate the dynamic principle and performance of underwater vehicles in real applications with complex external conditions. Here, we propose a type of combustion-enabled underwater vehicles that can perform stable high-speed motions under dynamic fluid environment. Experiments are conducted to test the kinematic performance. Numerical simulations are developed to investigate the fluid–solid interaction phenomenon, and theoretical modeling is derived to study the dynamic principle of the combustion actuation process. The experimental, numerical, and theoretical results are compared with satisfactory agreements. The underwater vehicles perform ~3.4 body-length distance within 0.2 s and a maximum speed of ~30 body-length per second in horizontal direction. Parametric studies are conducted to investigate the sensitivity of the key factors to the kinematic performance of the reported underwater vehicles. In the end, we report the hybrid combustion-enabled underwater vehicles (CUVs) that combined with propeller to realize continuous driving for multi-mode operations. The experimental, numerical, and theoretical results indicate that hybrid CUVs can achieve more flexible and controllable motion performance.