555 research outputs found

    A rapid numerical solution to subsonic flow over planar and axisymmetric profiles at an angle of attack of 0 deg

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    A numerical solution is presented for the incompressible flow over thin planar and axisymmetric profiles at an angle of attack of 0 degrees. The method uses a finite-difference field solution to the governing equation with a Gauss-Seidel successive overrelaxation scheme. However, the use of a simple Cartesian grid system restricts this method to slender profiles. Results are presented for a cambered airfoil, airfoil in wall effect (two-dimensional flowthrough inlet), body of revolution, and flowthrough nacelle. A computer program is presented which can be used for any of the previously mentioned cases with simple input changes. Results for compressible flow are available with the use of the appropriate two-dimensional or axisymmetric compressibility corrections. Computational time for a typical field calculation of 3000 grid points and 200 cycles through the field is less than 1 minute with less than 50,000 octal storage on the Control Data Corporation 6600 computing system

    Aerodynamic Performance Studies for Supersonic Cruise Aircraft

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    Technical progress made in each of the disciplinary research areas affecting the design of supersonic cruise aircraft is discussed. The NASA Supersonic Cruise Aircraft Research program has supported an expanded research program in aerodynamics including an ever growing experimental data base, methodology development across the Mach number range, and sonic boom. Progress in the aerodynamics area could facilitate the choice of the highly swept subsonic leading edge, arrow wing, known for superior supersonic cruise efficiency

    Making Inclusive Schooling Part of Our Daily Journey

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    Introduction by: Jackie Czamanske, Regional Field Facilitator, NYSED S3TAIR Project As a School Improvement Specialist, I’ve facilitated numerous discussions over the years on how a school district may address the various challenges it faces. During these conversations, teams often voice their fears on how including students with disabilities may negatively affect a school\u27s overall performance. The Rochester City School District’s World of Inquiry School provides a solid illustration on how high expectations and inclusion can lock arms in a large urban environment to achieve a performance-enhanced setting for all students. “Are We There Yet?” gives building administrators and leaders an intimate illustration of one school\u27s journey to create an inclusive environment. Concrete guidance on structures, culture, collaboration and a developmental implementation model provide navigational tools on how to “Get the world for EVERY student!

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

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    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

    187 - Modeling the Dynamics of Chromosomal Alteration Progression in Cervical Cancer: A Computational Model

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    Cervical cancer is a complex disease characterized by unpredictable genetic alterations of cells. Computational modeling may be applied to simulate the growth and behavior of cervical cancer within a tissue and the progression of the disease throughout the body. In our computational model, individual cells have the ability to transform behavior between the following states: healthy, precursor lesion (CN1, CN2, CN3), and cancer. Each cell state has a different mutation rate, reproductive rate, and cell life span. Our model simulates the transformation of cells into these different states. The data from our computational model shows the day-to-day growth of cancer within a tissue, and the progression of a cell evolving from healthy to cancerous. Our model suggests how cancer cells become dominant over time within a system and outgrow healthy tissue. Alterations to this model may help determine effectiveness of treatments on individual cells

    Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft

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    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

    A preliminary study of the performance and characteristics of a supersonic executive aircraft

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    The impact of advanced supersonic technologies on the performance and characteristics of a supersonic executive aircraft was studied in four configurations with different engine locations and wing/body blending and an advanced nonafterburning turbojet or variable cycle engine. An M 2.2 design Douglas scaled arrow-wing was used with Learjet 35 accommodations. All four configurations with turbojet engines meet the performance goals of 5926 km (3200 n.mi.) range, 1981 meters (6500 feet) takeoff field length, and 77 meters per second (150 knots) approach speed. The noise levels of of turbojet configurations studied are excessive. However, a turbojet with mechanical suppressor was not studied. The variable cycle engine configuration is deficient in range by 555 km (300 n.mi) but nearly meets subsonic noise rules (FAR 36 1977 edition), if coannular noise relief is assumed. All configurations are in the 33566 to 36287 kg (74,000 to 80,000 lbm) takeoff gross weight class when incorporating current titanium manufacturing technology

    Method for the Calculation of DPA in the Reactor Pressure Vessel of Atucha II

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    One of the limiting factors of the life of a nuclear power plant (NPP) is the state of the reactor pressure vessel (RPV). Embrittlement is the most important effect affecting RPV aging. The irradiation with neutrons, especially fast neutrons, is the primary cause of this embrittlement. NPP safe operation requires to ensure RPV integrity over its lifetime, threatened by the neutron radiation-induced embrittlement. In this paper, we identify the areas where the RPV neutron radiation is maximum and perform calculations of the displacement-per-atom (DPA) rate in those areas using the MCNP5 code. It was determined that the maximum DPA rate in the RPV wall with fresh fuel element (FE) is 3.76(3) × 10-12 s-1, it takes place in front of FEs BA42 and BL43, and it is symmetrical about the central channel, LG04, and LH03
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