Direct Numerical Simulation Of Turbulent Flow Over Biomimetic Non-smooth Surface And Drag Reduction Mechanism Analyses

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...