【作者】 封云；

【导师】 丛茜；

【作者基本信息】 吉林大学 ， 农业机械化工程， 2005， 硕士

【摘要】 本论文从数值模拟角度结合仿生学相关理论用有限体积法来探索非光滑表面的减阻机理。设计了5 种沟槽型仿生非光滑表面,用大型有限元软件ANSYS和专业流体分析软件FLUENT 对36 种流场进行了数值模拟,验证了软件分析非光滑表面流场的精度及可靠性,为CFD 方法探索非光滑减阻问题提供依据,将工程分析人员从繁琐的编程中解放出来。从剪应力、速度场、湍流强度、湍流耗散率、雷诺应力和涡量等方面对计算结果进行分析,从沟槽壁面曲线斜率、湍流拟序结构、边界层厚度、层流底层厚度和二次涡等角度解释非光滑减阻机理及非光滑形态对减阻的影响,并提出优化的沟槽形态及减阻最佳的沟槽形状设计准则。上述研究工作及所取得的研究成果,为微观尺寸的非光滑表面减阻的理论研究提供良好的基础。更多还原

【Abstract】 Turbulent drag exists in the flow transport, aviation and navigation fields and isthe most energy consumation.There are some shortage and localization in existing drag redution technologiesincluding microbubbles drag reduction,ploymer drag reduction,bedload drag redutionand magnetism drag redution and so on. Riblets on the shark skin which is finedistance and arranged in flow direction are observed when shark swimming at highspeed. And similar non-smooth surface which can reduce drag also exist in whale andpig skin when they are swimming. Non-smooth surface on the biology skin which isdirectly related not only with descendiblity but also with biology habit andenvironment provides new idea for studying turbulence drag redution based onbiomimetic.Five riblet biomimetic non-smooth surfaces are designed and simulate thirty-sixflow fields with finite volume method in single computational domain. B-L in nearwall and RSM are applied. Hexahedron map mesh is applied in triangle and scallopriblet, but tetrahedron free mesh is applied in blade one.Twenty-six flow field over triangle riblet with α=60o, s=0.1mm andh=8.66×10-2mm are computed. Reliability and precision of simulation can be provedbecause the simulation result is in good agreement with existing experimental dataand with theory computation result, which provides feasibility for simulating flowfield over biomimetic non-smooth surface with software.It is educed through comparing flow field over triangle riblet with更多还原