Noise and performance calibration study of a Mach 2.2 supersonic cruise aircraft

The baseline configuration of a Mach 2.2 supersonic cruise concept employing a 1980 - 1985 technology level, dry turbojet, mechanically suppressed engine, was calibrated to identify differences in noise levels and performance as determined by the methodology and ground rules used. In addition, economic and noise information is provided consistent with a previous study based on an advanced technology Mach 2.7 configuration, reported separately. Results indicate that the difference between NASA and manufacturer performance methodology is small. Resizing the aircraft to NASA groundrules results in negligible changes in takeoff noise levels (less than 1 EPNdB) but approach noise is reduced by 5.3 EPNdB as a result of increasing approach speed. For the power setting chosen, engine oversizing resulted in no reduction in traded noise. In terms of summated noise level, a 6 EPNdB reduction is realized for a 5% increase in total operating costs

Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft

NASA computer codes in the areas of preliminary sizing and enroute performance, takeoff and landing performance, aircraft noise prediction, and economics were used in a preliminary noise tradeoff study for a Mach 2.7 design supersonic cruise concept. Aerodynamic configuration data were based on wind-tunnel model tests and related analyses. Aircraft structural characteristics and weight were based on advanced structural design methodologies, assuming conventional titanium technology. The most advanced noise prediction techniques available were used, and aircraft operating costs were estimated using accepted industry methods. The 4-engines cycles included in the study were based on assumed 1985 technology levels. Propulsion data was provided by aircraft manufacturers. Additional empirical data is needed to define both noise reduction features and other operating characteristics of all engine cycles under study. Data on VCE design parameters, coannular nozzle inverted flow noise reduction and advanced mechanical suppressors are urgently needed to reduce the present uncertainties in studies of this type

IN-FLIGHT SHOCK-WAVE PRESSURE MEASUREMENTS ABOVE AND BELOW A BOMBER AIRPLANE AT MACH NUMBERS FROM 1.42 TO 1.69

In-flight shock wave pressure measurements above and below bomber aircraft at mach 1.42 to 1.6

Variability in sonic-boom signatures measured along an 8000-foot linear array

Variability in sonic boom signatures measured along 8000 foot linear microphone arra

Ground measurements of shock-wave pressure for fighter airplanes flying at very low altitudes and comments on associated response phenomena

Ground measurements of shock wave pressure for fighter aircraft at very low altitude

Noise measurement evaluations of various takeoff-climbout profiles of a four-engine turbojet transport airplane

Noise measurement evaluations of various takeoff-climbout profiles of four engine turbojet transport airplan

Wolf-like or dog-like? A comparison of gazing behaviour across three dog breeds tested in their familiar environments

Human-directed gazing, a keystone in dog\u2013human communication, has been suggested to derive from both domestication and breed selection. The influence of genetic similarity to wolves and selective pressures on human-directed gazing is still under debate. Here, we used the \u2018unsolvable task\u2019 to compare Czechoslovakian Wolfdogs (CWDs, a close-to-wolf breed), German Shepherd Dogs (GSDs) and Labrador Retrievers (LRs). In the \u2018solvable task\u2019, all dogs learned to obtain the reward; however, differently from GSDs and LRs, CWDs rarely gazed at humans. In the \u2018unsolvable task\u2019, CWDs gazed significantly less towards humans compared to LRs but not to GSDs. Although all dogs were similarly motivated to explore the apparatus, CWDs and GSDs spent a larger amount of time in manipulating it compared to LRs. A clear difference emerged in gazing at the experimenter versus owner. CWDs gazed preferentially towards the experimenter (the unfamiliar subject manipulating the food), GSDs towards their owners and LRs gazed at humans independently from their level of familiarity. In conclusion, it emerges that the artificial selection operated on CWDs produced a breed more similar to ancient breeds (more wolf-like due to a less-intense artificial selection) and not very human-oriented. The next step is to clarify GSDs\u2019 behaviour and better understand the genetic role of this breed in shaping CWDs\u2019 heterospecific behaviour

Sonic boom and drag evaluation of supersonic jet concepts

This paper evaluates three different class supersonic airliners (Concorde, Cranfield E-5, and NASA QueSST X-plane) in a multidisciplinary design analysis optimization (MDAO) environment in terms of their sonic boom intensities and aerodynamic performance. The aerodynamic analysis and sonic boom prediction methods are key to this research. The panel method PANAIR is integrated to perform automated aerodynamic analysis. The drag coefficient is corrected by the Harris wave drag formula and form factor method. For sonic boom prediction, the near-field pressure is predicted through the Whitham F-function method. The F-function is decomposed to the F-function due to volume and the F-function due to lift to see their individual effect on sonic boom. The near-field signature propagates in a stratified windy atmosphere using the waveform parameter method. The aerodynamic results are compared with experimental data and the sonic boom prediction results are validated by the NASA PCBoom program. Through the evaluation, we find a direct link between the wave drag and the first derivative of the volume distribution. The sonic boom intensity is influenced by the lift distribution and the volume change rate. The study helps to study the feasibility of low-boom and low-drag supersonic airliners

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior