The unsteady flow characteristics of a supercritical OAT15A airfoil with shock control bump were numerically studied by wall-modeled large eddy simulation. numerical method was first validated the buffet and nonbuffet cases baseline airfoil. Both pressure coefficient velocity fluctuation coincided well experimental data. Then, four different bumps tested. A height h/c = 0.008 location xB/c 0.55...

The efficiency of an airfoil can be improved by adjusting its surface. CFD software was used to investigate a 2D with and without spanwise semicircular groove on the upper NACA0012 airfoils grooves were analyzed using k-ω turbulence model. lift drag coefficients compared. To effect location efficiency, added in various locations compared smooth airfoil. flow velocity remained constant at 20 m/s...

The performance of a generic surfboard fin is investigated in a cavitation tunnel to gain basic understanding of the viscous flows involved for future systematic experimental and computational studies. Measurements of lift and drag forces, pitching moment and results of flow visualisation are presented. Surface flow visualisation studies reveal relatively complex boundary layer transition and s...

ROYAL AIRCRAFT ESTABLISHMENT Some simple conical c~mbcr shapes to produce low lift-depend,cnt drag on a slender delta wing G. G. Brebner This note presents some of the theoretical aerodynamic characteristics of narrow delta wings having flat csntre portions and two types of simple conical camber designed to produce zero load at the leading edge at the design C,.,. Slender wing theory is used in...

An orthogonal experiment was conducted to study the effects of aspect ratio, camber fore wing, and gap ratio front rear wing panels on hydrodynamic performance double-vane otter boards. The design comprised three factors (each having levels), namely (1.0, 1.5, 2.0), (0.12, 0.14, 0.16), (0.25, 0.30, 0.35), drag coefficient Cx lift Cy nine board models obtained in a wind tunnel experiment, lift–d...

In this paper, 3D flow past a long tapered tower is examined. A tapered tower is described by the taper ratio. Tapered cylinders are a good description of many structures, like wind turbine tower e.t.c. Similar to the flow around cylinders, the Reynolds number is the important flow parameter, and the Strouhal number represents the shedding frequency. These flow patterns are difficult to predict...

In this article, we introduce a computational methodology for golf disc shape optimization that employs novel parameterization by cubic B-splines. Through application of batch Computational Fluid Dynamics simulations and Machine Learning, the yields functional relationships—so-called surrogate models—between flying rotating its flight characteristics. The models facilitate free constrained in b...

For golfers, the length of flight distance is very important for improving scores. Therefore, surface a golf ball provided with innumerable dents called dimples to improve distance. These can be characterized by dimple occupancy and volume ratio. we manufactured model balls in which was changed diameter number dimples, depth change Fifteen were designed using 3D CAD then printed. Using these ba...