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 (RANS) equations are used as a flow model together with the Spalart-Allmaras turbulence model to account for high Reynolds number effects. Using a viscous continuous adjoint formulation, the necessary ...

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 (RANS) equations are used as a flow model together with the Spalart-Allmaras turbulence model to account for high Reynolds number effects. Using a viscous continuous adjoint formulation, the necessary ...

Article history: Received: 25.10.2014. Received in revised form: 19.03.2014. Accepted: 20.03.2014. To analyze the air flow interference between upper and lower wings in axial ring wing configuration, NASA SC(2)-1006 supercritical airfoil is chosen as the basic airfoil. Flow field around the doublewing structure with different relative distances between upper and lower wings is numerically simul...

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...

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 ...

For a century, researchers have used the standard lift coefficient C(L) to evaluate the lift, L, generated by fixed wings over an area S against dynamic pressure, ½ρv(2), where v is the effective velocity of the wing. Because the lift coefficient was developed initially for fixed wings in steady flow, its application to other lifting systems requires either simplifying assumptions or complex ad...

A new set of higher-order analytic solutions is introduced for the critical cases of: (a) ballistic skip trajectories with initial speed greater than the circular orbital speed (supercircular case); (b) shallow ballistic entry with entry speed less than the circular orbital speed (subcircular case); and (c) shallow ballistic entry from low circular orbits (circular case). Both non-circular case...

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...

The cylindrical flow around a cylinder is present in several engineering problems. Moreover, the pattern rotating more complex than that cylinder. In this paper, at different speed ratios investigated by means of large-eddy simulations. particular, lift coefficient CL, drag CD, lift-to-drag ratio k, Strouhal number St, field each section, and three-dimensional eddy structure are compared ratios...