Modelling hydrodynamic characteristics of the underwater glider based on Computational Fluid Dynamics

Abstract

The underwater glider is buoyancy-propelled Autonomous Underwater Vehicle (AUV). Their propulsion relies upon changing their buoyancy with internal pumping systems enabling them upward and downward motion. In the presented paper, the forward gliding motions are generated by hydrodynamic lift forces exerted on a pair of hydroplanes attached to a glider hull. The hydrodynamic characteristics of a glider were determined using Computational Fluid Dynamics (CFD). A 3D model was created for the simulation of flow behaviour in the Baltic Sea. The lift and drag forces distribution at different angles of attack was studied for Reynolds number 105. The flow velocity was 0.5 m·s-1 and the angle of the attack varied from -30° to 30° in steps of 2°. Results from the CFD constitute the basis for the calculation the equations of motions of the glider in 6 degrees of freedom. The vehicle motion simulation will be achieved through numeric integration of the equations of motion. This work will contribute to dynamic modelling and three-dimensional motion simulation of the torpedo-shaped underwater glider.

Identification of particular hydrodynamic parameters for a modular type 4 DOF underwater vehicle by means of CFD method

“…However, the optimised shape of a vehicle is provided by a computer-aided geometric definition (CAGD). Therefore, the integration of CFD and CAGD determines the optimum parameters, such as resistance and pressure (Vasudev et al, 2014). Mitra et al (2019) proposed certain improvement principles in AUV design based on their numerical and experimental results on free streaming turbulence.…”

“…The CFD results were verified using water tunnel experimental tests. In another study (Stryczniewicz et al , 2019), the hydrodynamic properties of three-dimensional (3D) UUV models were determined using a CFD programme, and the validity of the model was proven by test drives in the Baltic Sea. Mitra et al (2020) conducted experimental and numerical studies on inclined channel beds to investigate the hydrodynamic properties of AUV bodies for flows of different R e s. It was tried to estimate the uncertainties in the field of turbulent velocity around AUVs by means of statistics of the measured values.…”