Langley airfoil-research program

An overview of past, present, and future airfoil research activities at the Langley Research Center is given. The immediate past and future occupy most of the discussion; however, past accomplishments and milestones going back to the early NACA years are dealt with in a broad-brush way to give a better perspective of current developments and programs. In addition to the historical perspective, a short description of the facilities which are now being used in the airfoil program is given. This is followed by a discussion of airfoil developments, advances in airfoil design and analysis tools (mostly those that have taken place over the past 5 or 6 years), and tunnel-wall-interference predictive methods and measurements. Future research requirements are treated

Theoretical and experimental pressure distributions for a 71.2 degree swept arrow-wing configuration at subsonic, transonic, and supersonic speeds

A wind-tunnel test of an arrow-wing body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control-surface deflections, was conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using current state-of-the-art and newly developed attached- and separated-flow methods. Conditions were delineated under which these theories provide accurate basic and incremental aeroelastic loads predictions. Current state-of-the-art linear and nonlinear attached-flow methods were adequate only at small-angle-of-attack cruise conditions. Of the several separated-vortex methods evaluated, only the one utilizing a combination of linear source and quadratically varying doublet panels showed promise of yielding accurate loads distributions at moderate to large angles of attack

Semiempirical method for predicting vortex-induced rolling moments

A method is described for the prediction of rolling moments on a wing penetrating a vortex velocity field generated by a large aircraft. Rolling moments are determined from lifting pressure coefficients computed with an inviscid-flow linear panel method. Two empirical corrections are included to account for the lifting efficiency of an airfoil section and the local stall on the wing. Predicted rolling moments are compared with those from two windtunnel experiments. Results indicate that experimental rolling moments, for which the Reynolds number of the following wing is low, should be interpreted with caution

The prediction of pressure distributions on an arrow-wing configuration including the effect of camber, twist, and a wing fin

Wind tunnel tests of an arrow wing body configuration consisting of flat, twisted, and cambered twisted wings were conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. A variety of leading and trailing edge control surface deflections were included in these tests, and in addition, the cambered twisted wing was tested with an outboard vertical fin to determine its effect on wing and control surface loads. Theory experiment comparisons show that current state of the art linear and nonlinear attached flow methods were adequate at small angles of attack typical of cruise conditions. The incremental effects of outboard fin, wing twist, and wing camber are most accurately predicted by the advanced panel method PANAIR. Results of the advanced panel separated flow method, obtained with an early version of the program, show promise that accurate detailed pressure predictions may soon be possible for an aeroelasticity deformed wing at high angles of attack

Simulation of time-varying ascent loads on arrays of shuttle tiles in a large transonic tunnel

For abstract, see A82-24682

Results of correlations for transition location on a clean-up glove installed on an F-14 aircraft and design studies for a laminar glove for the X-29 aircraft accounting for spanwise pressure gradient

Results of correlative and design studies for transition location, laminar and turbulent boundary-layer parameters, and wake drag for forward swept and aft swept wings are presented. These studies were performed with the use of an improved integral-type boundary-layer and transition-prediction methods. Theoretical predictions were compared with flight measurements at subsonic and transonic flow conditions for the variable aft swept wing F-14 aircraft for which experimental pressure distributions, transition locations, and turbulent boundary-layer velocity profiles were measured. Flight data were available at three spanwise stations for several values of sweep, freestream unit Reynolds number, Mach numbers, and lift coefficients. Theory/experiment correlations indicate excellent agreement for both transition location and turbulent boundary-layer parameters. The results of parametric studies performed during the design of a laminar glove for the forward swept wing X-29 aircraft are also presented. These studies include the effects of a spanwise pressure gradient on transition location and wake drag for several values of freestream Reynolds numbers at a freestream Mach number of 0.9

Sonic Boom: Six Decades of Research

Sonic booms generated by aircraft traveling at supersonic speeds have been the subject of extensive aeronautics research for over 60 years. Hundreds of papers have been published that document the experimental and analytical research conducted during this time period. The purpose of this publication is to assess and summarize this work and establish the state-of-the-art for researchers just entering the field, or for those interested in a particular aspect of the subject. This publication consists of ten chapters that cover the experimental and analytical aspects of sonic boom generation, propagation and prediction with summary remarks provided at the end of each chapter. Aircraft maneuvers, sonic boom minimization, simulation techniques and devices as well as human, structural, and other responses to sonic booms are also discussed. The geometry and boom characteristics of various low-boom concepts, both large civil transports and smaller business-jet concepts, are included. The final chapter presents an assessment of civilian supersonic overland flight and highlights the need for continued research and a low-boom demonstrator vehicle. Summary remarks are provided at the end of each chapter. The studies referenced in this publication have been drawn from over 500 references

Leadership, the logic of sufficiency and the sustainability of education

The notion of sufficiency has not yet entered mainstream educational thinking, and it still has to make its mark upon educational leadership. However, a number of related concepts – particularly those of sustainability and complexity theory – are beginning to be noticed. This article examines these two concepts and uses them to critique the quasi-economic notion of efficiency, before arguing that the concept of sufficiency arises naturally from this discussion. This concept, originally derived from environmental thinking, has both metaphorical and practical impact for educational organizations and their leadership. An examination of three possible meanings suggests that while an embrace of an imperative concept of sufficiency seems increasingly necessary, its adoption would probably lead to a number of other problems, as it challenges some fundamental societal values and assumptions. Nevertheless, the article argues that these need to be addressed for the sake of both sustainable leadership and a sustainable planet

Cultural and serological analysis of the salmonella status of Australian pig production

The microbiological quality of food of animal origin is receiving widespread scrutiny as outbreaks of food-borne disease are increasingly reported in developed countries. In Australia, the pig industry has embarked on a national program to define and enhance the quality, including microbiological quality, of pig meat. The National Pig Meat Hygiene Program (PMHP) is part of this initiative, and aims to develop baseline data for microorganisms on pig meat, including public health pathogens, and to develop and implement management strategies to enhance the microbial quality of Australia\u27s pig meat production. The study reported here measured salmonella contamination on pig meat and carcases sampled nationwide, and adapted and validated an enzyme linked immunosorbent assay (ELISA) for evaluating the salmonella infection status of pig herds