Boeing Commercial Airplanes

About: Boeing Commercial Airplanes is a based out in . It is known for research contribution in the topics: Noise & Turbulence. The organization has 1623 authors who have published 1711 publications receiving 50715 citations. The organization is also known as: BCA & Boeing Commercial Airplanes, BCA.

A new version of detached-eddy simulation, resistant to ambiguous grid densities

Abstract: Detached-eddy simulation (DES) is well understood in thin boundary layers, with the turbulence model in its Reynolds-averaged Navier–Stokes (RANS) mode and flattened grid cells, and in regions of massive separation, with the turbulence model in its large-eddy simulation (LES) mode and grid cells close to isotropic. However its initial formulation, denoted DES97 from here on, can exhibit an incorrect behavior in thick boundary layers and shallow separation regions. This behavior begins when the grid spacing parallel to the wall Δ∥ becomes less than the boundary-layer thickness δ, either through grid refinement or boundary-layer thickening. The grid spacing is then fine enough for the DES length scale to follow the LES branch (and therefore lower the eddy viscosity below the RANS level), but resolved Reynolds stresses deriving from velocity fluctuations (“LES content”) have not replaced the modeled Reynolds stresses. LES content may be lacking because the resolution is not fine enough to fully support it, and/or because of delays in its generation by instabilities. The depleted stresses reduce the skin friction, which can lead to premature separation.

An overview on the use of titanium in the aerospace industry

Abstract: Titanium and titanium alloys are excellent candidates for aerospace applications owing to their high strength to weight ratio and excellent corrosion resistance. Titanium usage is, however, strongly limited by its higher cost relative to competing materials, primarily aluminum alloys and steels. Hence the advantages of using titanium must be balanced against this added cost. The titanium alloys used for aerospace applications, some of the characteristics of these alloys, the rationale for utilizing them, and some specific applications of different types of actual usage, and constraints, are discussed as an expansion of previous reviews of β alloy applications. [1,2]