The Analysis On Hydrodynamic Performances Of An Underwater Towed System

Underwater towed vehicle is a widely used underwater marine monitoring environme nta ldynamic monitoring system, which has a special purpose in oceans, lakes and inland underwaterenvironmental monitoring and inspection of hydraulic structures, marine resources and otheraspects of the investigation. Drag the underwater environment monitoring sensors mounted invivo nature of the work requires a stable posture while dragging the body of work, and has fastand flexible attitude and depth of regulation and control, hence the group members put forwardtwo kinds of underwater towed vehicle model.The paper drag the power factor of underwater towed vehicle, cable and controlmechanism as a whole, considering the influence between their each other, establis hingcomplete hydrodynamic mathematical model of multi-degree of freedom can be controlledunderwater towed system, and do hydrodynamic response numerical calculation of the twounderwater towed vehicle design model based on this mathematical model.First, the paper propose and establish a hydrodynamic mathematical model of underwatertowed system. In this model, Ablow and Schechter model be used as the control equations ofcable, six degrees of freedom motion equations be used to describe the state of the underwatertowed vehicle, which is first put forward by Gertler and Hagen and improved by Abkowitz,and composite the mathematical model of the entire underwater hydrodynamic towed systemby coupling the control cable, towed vehicle equations and boundary conditions at theconnection point.Secondly, the paper build physical models of the two underwater towed vehicle designmodel, which can be used to calculate, and describe some of the key technologies of the Fluentsoftware, some of the key process and technology of both mixed Fortran programs involved inin this article, to prepare for later calculations.Once again, the paper do numerical simulation calculate about ducted propeller, which isthe main control mechanism of underwater towed vehicle. The numerical simulation involvingopen water test, single propeller yaw motion, with a towed vehicle yaw motion, thus get the influence on the towed vehicle to the ducted propeller flow field, which can made a goodfoundation and bedding for the calculation of the underwater towed system.Finally, the paper do hydrodynamic response numerical calculation of the two underwatertowed vehicle design model based on the mathematical model. Steering control mechanis msuch as hydrofoil, rudder and propeller duct, control the depth and posture of towed vehicle,and calculate the hydrodynamic response of underwater towed system.