Toward the Environmental Design of Library Buildings

published or submitted for publicatio

Split digraphs

We generalize the class of split graphs to the directed case and show that these split digraphs can be identified from their degree sequences. The first degree sequence characterization is an extension of the concept of splittance to directed graphs, while the second characterization says a digraph is split if and only if its degree sequence satisfies one of the Fulkerson inequalities (which determine when an integer-pair sequence is digraphic) with equality.Comment: 14 pages, 2 figures; Accepted author manuscript (AAM) versio

Vortex-lift roll-control device

A wing is described for aircraft of cropped, arrow-type planform with thin leading and side edges. The wing has a pivotable tip to alter the crop angle of the wing during flight. Increasing the crop angle causes the wing side edge to become a trailing edge which reduces the strength of the side edge vortex flow. Decreasing the crop angle causes opposite results, in particular the side edge is now a leading edge and can generate a leading edge vortex flow. The wing constitutes a roll control device for aircraft of the stated design particularly effective at higher angles of attack

Modified Multhopp lifting surface loading program

Computer program determines the longitudinal subsonic aerodynamic characteristics of composite wings. The program uses the basic theoretical method of Multhopp in predicting the loading data

Modified Multhopp mean camber computer program

Computer program which determines the mean camber surface required to support a given set of loadings on a composite wing in subsonic compressible flow has been developed

Americans Have a Right to Review Any Healthcare Bill before Congress Acts

The final version of the legislation should be posted on the Internet for at least 72 hours so that anybody who wants to can read the bill.Lamar Alexander, health care reform, healthcare reform, healthcare, health care, Tennessee, insurance

A New Manhattan Project for Clean Energy Independence

Seven “grand challenges” for the next five years: plug-in electric cars and trucks, carbon capture, solar power, nuclear waste, advanced biofuels, green buildings, and fusionalternative energy, plug-in electric cars, carbon capture, solar power, nuclear waste, viofuels, green, fusion, Oak Ridge

The Most Important Legislation You've Never Heard Of

Keeping our brainpower advantage — and our jobs from going overseasAmerica COMPETES Act, Lamar Alexander

Minimum trim drag design for interfering lifting surfaces using vortex-lattice methodology

A new method has been developed by which the mean camber surface can be determined for trimmed noncoplanar planforms with minimum vortex drag under subsonic conditions. The method uses a vortex lattice and overcomes previous difficulties with chord loading specification; it uses a Trefftz plane analysis to determine the optimum span loading for minimum drag, then solves for the mean camber surface of the wing which will provide the required loading. Pitching-moment or root-bending-moment constraints can be employed as well at the design lift coefficient. Sensitivity studies of vortex-lattice arrangement have been made with this method and are presented. Comparisons with other theories show generally good agreement. The versatility of the method is demonstrated by applying it to (1) isolated wings, (2) wing-canard configurations, (3) a tandem wing, and (4) a wing-winglet configuration

In-flight and wind tunnel leading-edge vortex study on the F-106B airplane

The vapor screen technique was successfully applied to an F-106B fighter aircraft during subsonic and transonic maneuvers. This system has allowed the viewing of multiple vortex systems on the wing upper surface at angles of attack less than 19 deg. In addition, similarities as well as differences were determined to exist between the vortex systems for a full scale semispan model and the flight vehicle at 20 deg incidence. Furthermore, variations in Reynolds number and Mach number were identified as to how they affect vortex system details at flight conditions