Performance Analysis On The Seabed Sediment Fidelity Sampler Based On ANSYS And FLUENT

The seabed sediment sample is one of the basic means to the marine environment and resource investigation, sampling reliable largely lies on the fidelity of grabbed sample, and high performance requirements for seabed sampling equipment are presented. According to the shortages of seabed sediment sampler home and abroad, the design of a new seabed sediment fidelity sampler is put forward, the injection sample performance, thermal insulation and pressurize performance with flushing induced by ocean current and hydrodynamic performance are further researched by ANSYS and FLUENT, a series of parameters optimized for design of seabed sediment sampler are obtained, which are of importance for technicians to higher seabed sediment fidelity sampler's design. The contents are as follows:1. Based on having some ideas on seabed sediment engineering geological properties, according to the theory of expansion of spherical cavities, the mechanical model during injecting sample process is established, the influencing factors on the status of the samples during injecting sample process are analyzed, the depth and the drag computing formulas during injecting sample process are derived, which lay the theoretical foundation for high fidelity sampler's design.2. According to the theory of the conversation of energy and the transient heat transfer, the temperature field of finite element model of fidelity structure during sampler's recovery is developed and numerically calculated, the temperature field of sampler's fidelity structure and sample are shown, three thermal insulation methods of the sample tube are acquired, the influencing factors on thermal insulation distribution are analyzed, based on simulation and experiments, the relative coefficients of the thermal layer of the sample tube are optimized, the value scope of the thermal layer thickness thermal coefficient of heat conductivity satisfied with design criteria is presented, which afford the theoretical foundation for thermal insulating device.3. In terms of fluid dynamic theory, the Reynolds Average Navier-Stokes equations of incompressible fluid are solved by finite element method, the hydrodynamic performance during the free falling process and injection sampling process are numerically calculated with FLUENT 6.2, the influencing factors on the numerical results such as turbulence model and mesh size et al are analyzed, compared with relative experiments and data, the difference among the numerical results of the various models is got, five different mesh sizes applied in each model are analyzed, influencing on the numerical results adopted different wall mesh size is compared, the turbulence model and mesh size suitable for sampler are given finally. On condition that the sampler is in a different velocity, a different diving angle attack and a different geological state, the viscous fluid field distribution and drag performance of the sampler are researched, the pressure and velocity field distribution and lift and drag coefficients are obtained, compared with theoretical formula and empirical equations, the numerical results are approximately in accordance with the practical cases, and the research on hydrodynamic performance of the sampler has a high application value.