Hydrodynamic Analysis Of A Flying Wing Underwater Glider

In the current situation of the Marine Science's development in the world,application of underwater glider is more and more widely as the underwater moving platform,with advantages of low noise,strong endurance,low cost,energy saving and so on.At present,the development of the underwater glider is in various ways.Since 1989 the concept of underwater glider was put forward,research institutions around the world have developed a variety of underwater glider of different functions and performance.Flying wing underwater glider is a sort of new underwater glider in recent years,its difference from other underwater glider is,combine with the aerial design of blended wing body and flying wing,improving hydrodynamic performance through a configuration of highly integration of the body and the wing.This paper will design the configuration of a flying wing underwater glider,and do the hydrodynamic calculation and analysis of its movement,laying some foundation for the manufacturing of flying wing underwater glider prototype.With reference to the process and methods of flying wing aircraft's aerodynamic design,the flying wing underwater glider is divided into inner wing part and outer wing part to design.It's referred to the hydrodynamic design of legacy underwater gliders,make integrated design,then get some design plans.Use the CFD software FLUENT to calculate the lift and drag of each plan,compare the lift to drag ratio curves at design speed and different angle of attack,select the design plan with maximum lift to drag ratio for the final design.The detailed hydrodynamic performance,that the lift and drag characteristics of different speeds,different net buoyancy and different attack angle of the final design is analysed.The mathematical model of flying wing underwater glider's vertical movement is according to the six degree of freedom motion equation.The dynamic grid technology and UDF function in FLUENT is used to simulate the PMM test and obtain the hydrodynamic coefficients in the motion equations.Finally,the simulation program is built by VC++,the saw-tooth motion simulated through input of the flying wing underwater glider's hydrodynamic coefficients and control of net buoyancy.The size and position of net buoyancy,the range of gliding depth is adjusted to simulate the motion under various conditions,then contrast.The final result shows that flying wing underwater glider's hydrodynamic performance is better than legacy underwater glider,proving that the advantage of flying wing configuration.