Optimizing the NACA0015 airfoil which is widely applied in small-scale vertical axis wind turbine to make it has a better aerodynamic performance. In the optimization process, using CST parameterization method to perturb the airfoil geometry, the thickness and camber of the airfoil are selected as the constraint, and the value of the maximum tangential force coefficient is chosen as the objecti...

Nylon (PA) netting is widely used in purse seines and other fishing gears due to its high strength and good sinking performance. However, hydrodynamic properties of nylon netting of different characteristics are poorly understood. This study investigated hydrodynamic characteristics of nylon netting of different knot types and solidity ratios under different attack angles and flow velocities. I...

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...

The Breguet range equation indicates that to the first order of approximation range will be maximized by maximizing ML/D, where M is the Mach number and L/D is the lift/drag ratio. Since the drag coefficient increases very rapidly as the Mach number approaches one, this leads to the design of a long range aircraft which fly at high subsonic speeds, typically in the range Mach 0.8 to 0.85, just ...

This paper mainly researched on influence of vortex generator on lift coefficient and drag coefficient, when vortex generator is mounted on a flat plate. Vented cylinders were used as vortex generators which intensify vortex shedding in the wake of the vented cylinder as compared to base line circular cylinder which ensures more attached flow and increases lift force of the system. Firstly vent...

The morphology, kinematics and stiffness properties of lifting surfaces play a key role in the aerodynamic performance of vertebrate flight. These surfaces, as a result of their flexible nature, may move both actively, owing to muscle contraction, and passively, in reaction to fluid forces. However, the nature and implications of this fluid-structure interaction are not well understood. Here, w...

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...

Aerodynamic force generation and power requirements in forward flight in a fruit fly with modeled wing motion were studied using the method of computational fluid dynamics. The Navier-Stokes equations were solved numerically. The solution provided the flow velocity and pressure fields, from which the vorticity wake structure and the unsteady aerodynamic forces and torques were obtained (the ine...

We discuss a new numerical scheme involving adaptive boundary conditions which allows to compute, at very low Reynolds numbers, drag and lift of airfoils with rough surfaces efficiently with great precision. As an example we present the numerical implementation for an airfoil consisting of a line segment. The solution of the NavierStokes equations is singular at the leading and the trailing edg...

In this paper, two-dimensional computational fluid dynamics analyses were conducted to examine the rib effect on performance of NACA 0018 plain flapped airfoil. A mesh independence study was carried out and Spalart-Allmaras turbulence model selected for validation. Four various airfoil models designed: M1 (airfoil without flap structure), M2 with M3 a flap) M4 structure flap). The designed airf...