Rerearch On Thermal Underwater Glider Experiment Basin And Design Of The Glider

Thermal underwater gliders are autonomous underwater vehicles driven by the energy from thermocline. The performance of thermal underwater gliders depends greatly on the temperature gradient of ocean. The test of existing thermal underwater gliders and electrical underwater gliders were undertaken in straits or ports. This method has several shortcomings. First, test cost is very high. Second, it is hard to observe the gliding of gliders in the water and the test environment is fixed. In the end, the glider may not be recovered. Thus, the purpose of this thesis is to construct a basin to simulate the thermocline for the tests of thermal underwater gliders. Besides, the configuration of the glider is designed.This thesis firstly validates the feasibility of test basin for thermal underwater gliders with FLUENT software. A test system is designed, based on the principle of generating temperature gradient. The strength and rigidity checkings of the basin are undertaken with finite element software ALGOR and the results are valid. After selecting other equipment, a basin which can regulate the velocity and flowrate of hot and cold water inflows is constructed.A math model of phase change process of PCM is made with enthalpy method. The computational domain is discretized with external nodes method and the control equation is discretized based on the method of controlling cubage. The algorithm of solving the math model of phase change process of the underwater glider's PCM is available at last. With this algorithm, the numerical simulations of the temperature gradients in the basin are conducted and 10℃/m is chosen as the control object. In the thermocline simulation experiment, the 10℃/m temperature gradient is obtained after programming the PLC with STEP7, which controls the hot and cold water inflows.Last, the hydrodynamic analysis on different types of underwater gliders'shape is made with Fluent. With the target of maximizing the lift-drag ratio to improve the efficiency of the glider, the shape of main body is designed and NACA wings are selected as appendages. Then, the configuration of the underwater glider prototype is obtained.After these researches, many kinds of ocean thermocline can be simulated in the thermal underwater glider basin and the outline of the glider prototype is designed, which supply a good preparation for the phase change experiments and the motion control experiments of the thermal underwater glider.