Numerical investigation of a pair of self-propelled AUVs operating in tandem

Abstract

This paper investigates the influence of the propeller race on upstream and downstream self-propelled AUVs. Initially simulations of a self-propelled hull are performed at the Reynolds Number 3.2 × 10 6 with the commercial RANS code ANSYS CFX 12.1, utilising a body force model to replicate the impact of the propeller utilising momentum source terms. This is then extended to consider a fleet of two self-propelled vehicles operating at a range of longitudinal offset and transverse separations. The results highlight that operation in close proximity to another self-propelled vessel has a significant impact of both the flow around the hull and drag experienced by the vehicle. A propeller race deduction is proposed to account for the increase in vehicle drag due to the propulsors of other vehicles. The propeller race deduction is dependent upon both longitudinal and transverse separation. From a vehicle or mission design perspective, it is important to correctly understand the true propulsive energy budget of the vehicle and its impact on both range and endurance. This study highlights the importance of considering both thrust deduction and any propeller race deductions when calculating the propulsive power consumption of an individual or fleet of vehicles.

Experimental and Numerical Investigation of a Longfin Inshore Squid’s Flow Characteristics

“…SST k-ω model known as a hybrid two equation model utilizes both k-ε and k-ω turbulent models for boundary layer and main flows, respectively. Besides, this model was verified to be suitable for high-Reynolds-number flows with separation (Menter (1994), Moshfeghi et al (2012), Shereena et al (2013), Vasudev et al (2014), Rattanasiri et al (2015), Tabatabaei et al (2015), Malazi and Olcay (2016)). …”

Study on the Motion Stability of the Autonomous Underwater Helicopter

“…CFD commercial software ANSYS Fluent is widely used to calculate the hydrodynamic performance of submersible vehicles [18,22,35,36] and provides a large number of turbulence models, among which the RANS model provides the most economical method for complex turbulent flow calculation. The two-equation model is the most widely used turbulence model in industrial CFD [29,[37][38][39]. This model solves two transport equations and simulates Reynolds stress by the eddy viscosity method.…”

A review on the hydrodynamic characteristics of autonomous underwater vehicles

“…Rattanasiri et al 44 performed numerical simulations on a pair of self-propelled AUV operating in tandem. Their principal purpose was to find the optimal distance between two vehicles for safer operations in multiple vehicles’ missions.…”