The present paper investigates the case of an airfoil placed in a turbulent jet. The Reynolds number based on the chord length is equal to 36,000 and the Mach number to 0.04. The unsteady, threedimensional incompressible flow around the airfoil is first computed with the LES module of the commercial solver FLUENT. An innovative procedure is then proposed to compute from the CFD computation, the...

It is well known that the addition of small amounts of long chain polymers produces dramatic effects on flowing fluids. A remarkable effect, recently observed experimentally, is the onset of ”elastic turbulence” in the limit of very low Reynolds number Re, provided elasticity is high enough [1]. In this regime, the polymer solution displays features typical of turbulent flows. Consequently, ela...

Classic models of fish schools and flying formations of birds are built on the hypothesis that the preferred locations of an individual are determined by the flow left by its upstream neighbor. Lighthill posited that arrangements may in fact emerge passively from hydroor aerodynamic interactions, drawing an analogy to the formation of crystals by intermolecular forces. Here, we carry out physic...

The complex and unsteady aerodynamics of vertical axis wind turbines (VAWTs) pose significant challenges for simulation tools. Recently, significant research efforts have focused on the development of new methods for analysing and optimising the aerodynamic performance of VAWTs. This paper presents an electric circuit model for Darrieus-type vertical axis wind turbine (DT-VAWT) rotors. The nove...

by Jacob Allen Cress The relationship between optical aberrations and coherent structures in the turbulent boundary layer is investigated in a series of experiments. A statistical model is derived using the “extended” Strong Reynolds Analogy that allows the total temperature to vary and also presumes pressure fluctuations in the boundary layer are negligible compared to temperature fluctuations...

Abstract Aerodynamic heating and temperature distribution are one of the problems that must be considered in design hypersonic rocket sled. In order to evaluate aerodynamic environment sled, typical monorail sled with cone cylinder combination is taken as research object, calculation methods such Modified Newton Theory, Reynolds Analogy Reference Enthalpy Method Fourier’s Law Heat Conduction us...

The drag and noise reduction of the flow around a cylinder is one important topics in hydrodynamics acoustics. In this paper, three typical bionic cylinders are designed based on serrated structure surface shark skin. Using Large eddy turbulence model Lighthill’s acoustic analogy method, characteristics smooth kinds at different Reynolds numbers were compared, was optimized. results show that m...

thinkers and philosophers have constantly benefited from different         approaches of reasoning to explore and justify their ideas. theses reasoning            approaches are considered as the principle instruments in speculative activities of the thinkers. to this end to achieve the procedure of thinking and the way philosophers achieve objectives, it is necessary to recognize their reasoni...