The Green's function approach of Giles and Pierce ( J. Fluid Mech. , vol. 426, 2001, pp. 327–345) is used to build the lift drag based analytic adjoint solutions for two-dimensional incompressible Euler equations around irrotational base flows. drag-based solution turns out have a very simple closed form in terms flow variables smooth throughout domain, while lift-based singular at rear stagnat...

The Direct Simulation Monte-Carlo technique (DSMC) is used for numerical analysis of rarefied-gas hypersonic flows near a blunt plate, wedge, two side-by-side plates and cylinders, sphere, torus, and rotating cylinder. Important kinetic effects that are specific for the transition flow regime have been found: nonmonotonic lift of plates, strong repulsive force between side-by-side plates and cy...

This article discusses the enhanced lift-drag ratio of a geometrically modified National Advisory Committee for Aeronautics 0012 aerofoil at low Reynolds number 40000. The study involves validating Averaged Navier Stokes Transition Shear Stress Transport model analysis flow around subject with profile angles attack ranging from 0 to 10°. coefficient lift drag increased by 70% an angle 6°. exten...

The research on tidal-current energy-capture technology mainly focuses the conditions of high flow velocity, focusing use differential pressure lift, while average velocity in most sea areas China is less than 1.5 m/s, especially marine aquaculture area, where energy needed to provide green locally. Due low this type it seriously affects effect which conducive exerting impact resistance. In reg...

Flapping flight is an increasingly popular area of research, with applications to micro-unmanned air vehicles and animal flight biomechanics. Fast, but accurate methods for predicting the aerodynamic loads acting on flapping wings are of interest for designing such aircraft and optimizing thrust production. In this work, the unsteady vortex lattice method is used in conjunction with three load ...

This note studies the accuracy of Isogeometric Analysis (IGA) applied in the simulation of incompressible flows around a cylinder in two and three dimensions. Quantities of interest, like the drag coefficient, the lift coefficient, and the difference of the pressure between the front and the back of the cylinder are monitored. Results computed with standard finite element methods are used for c...

In this study, the boundary element method is formulated to evaluate hydrodynamic characteristics of bodies including free surface effect. The method is based on two equations, the perturbation potential boundary integral and the pressure Kutta condition, which are solved simultaneously. The method uses isoparametric elements for both quantity and geometric on the boundary. The method is first ...

Supersonic channel airfoil design techniques have been shown to significantly reduce drag in high-speed flows over diamond shaped airfoils by Ruffin and colleagues. The effect of applying these techniques to a NACA 66-206 airfoil is presented. The design domain entails channel heights of 8-16.6% thickness-to-chord and speeds from Mach 1.5-3.0. Numerical simulations show an increase in the lift-...

Scour is a phenomenon that occurs as a result of natural erosion by ground water flow and transport of seabed material. In this research, scour around the legs of marine structures is simulated using the FLOW3D.V.9.3™ commercial software. The general scour model consists of two components, namely, the lift and thrust forces. The drag force, that is inserted to the structure, is a combination of...

Flow separation at the vehicle’s rear end is the major cause of an aerodynamic drag in a car. In order to delay the flow separation at the rear, bump-shaped vortex generators at the roof end of a car are tested in this paper for two different types of car models Sedan and Hatchback. The aerodynamic analysis is carried out using GAMBIT and FLUENT for Sedan and Hatchback models. Vortex Generators...