This paper reports the results of a computational study that was conducted to explore the effect of various Variable Camber Continuous Trailing Edge Flap (VCCTEF) configurations on the lift and drag of a NASA Generic Transport Model (GTM) wing section at a span-wise location called the break station that marks a sharp change in the wing trailing edge slope. The OVERFLOW solver with the the one-...

The influences of the leader in a group of V – flight formation are dealt with. The investigation is focused on the effect of its position and shape on aerodynamics performances of a given V – flight formation. Vortices generated the wing tip of the leader moves downstream forming a pair of opposite rotating line vortices. These vortices are generally undesirable because they create a downwash ...

This paper summarizes and discusses some critical aspects of flying hypersonically. The first is the L/D (lift over drag) ratio determining thrust that in turn depends on slenderness Küchemann’s τ parameter. second parameter found to depend relative importance wave versus friction drag. Ultimately, all engineering drag argued vorticity formed at expense vehicle kinetic energy, thus requiring wo...

In this study, we show how a novel self-adjusting, semi-pelagic otter board have high hydrodynamic efficiency and reduce seabed contact. The boards two adjustable flaps, which are controlled by on-board altimeters actuators, modifying their lift drag altering position in the water column. actuators governed Proportional Integral Derivative feedback system, uses altimeter data to maintain at pre...

The overwing nacelle (OWN) concept refers to aircraft designs where the engine is installed above wing. OWN configuration offers several advantages over conventional underwing (UWN) vehicles, which include improved fuel-burn and propulsive efficiencies due feasibility of ultrahigh-bypass-ratio turbofans, as well reduced noise. However, a nonoptimal design can result in large transonic drag pena...

1. Summary Nonplanar wings offer the possibility of reduced drag compared with planar wings of the same span and lift. However, aircraft are not compared on the basis of drag with fixed span and lift, making the integration and assessment of nonplanar wing concepts complex. This paper deals with some of these issues. A brief review of several concepts from winglets to ring wings is followed by ...

In this study, surface features such as dimples and bumps are introduced to the of a NACA 0012 airfoil study their effect on boundary layer separation, particularly at high angles attack. Six modified airfoils were designed with spherical pyramidical shapes. A computational fluid dynamics (CFD) analysis was conducted these models subsonic flow using Ansys Fluent. The used Shear Stress Transport...

Implications for flow resistance and sediment transport Michael P. Lamb* , Fanny Brun and Brian M. Fuller Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125 *[email protected] Key Points: 1. Direct measurements of lift and drag forces were made on cobbles in steep flume experiments with shallow, rough flow over a planar bed 2. As flows shall...

An adjoint-based Navier–Stokes design and optimization method for two-dimensional multi-element high-lift configurations is derived and presented. The compressible Reynolds-averaged Navier–Stokes equations are used as a flow model together with the Spalart–Allmaras turbulence model to account for high Reynolds number effects. When a viscous continuous adjoint formulation is used, the necessary ...

The northern spearnose poacher, Agonopsis vulsa, is a benthic, heavily armored fish that swims primarily using pectoral fins. High-speed kinematics, whole-body lift measurements, and flow visualization were used to study how A. vulsa overcomes substantial negative buoyancy while generating forward thrust. Kinematics for five freely swimming poachers indicate that individuals tend to swim near t...