333 research outputs found

    High-speed flow calculations past 3-D configurations based on the Reynolds averaged Navier-Stokes equations

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    A computational fluid dynamics tool has been developed capable of analyzing the viscous supersonic/hypersonic flow about realistic configurations. This techniques can predict the flow in regions of canopies, wings, and canards in addition to the usual simple symmetric configurations. It also allows for interactions between aerodynamic surfaces such as the vortex interaction between canards and wings

    User's manual for three-dimensional analysis of propeller flow fields

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    A detailed operating manual is presented for the prop-fan computer code (in addition to supporting programs) recently developed by Kutler, Chaussee, Sorenson, and Pulliam while at the NASA'S Ames Research Center. This code solves the inviscid Euler equations using an implicit numerical procedure developed by Beam and Warming of Ames. A description of the underlying theory, numerical techniques, and boundary conditions with equations, formulas, and methods for the mesh generation program (MGP), three dimensional prop-fan flow field program (3DPFP), and data reduction program (DRP) is provided, together with complete operating instructions. In addition, a programmer's manual is also provided to assist the user interested in modifying the codes. Included in the programmer's manual for each program is a description of the input and output variables, flow charts, program listings, sample input and output data, and operating hints

    Numerical simulation of the hypersonic flow around lifting vehicles

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    A method for solving the viscous hypersonic flow field around realistic configurations is presented. The numerical procedure for generating the required finite difference grid and the two-factored implicit flow solver are described. Results are presented for the shuttle orbiter and a generic wing-body configuration at hypersonic Mach numbers

    A supersonic three-dimensional code for flow over blunt bodies: Program documentation and test cases

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    The use of a computer code for the calculation of steady, supersonic, three dimensional, inviscid flow over blunt bodies is illustrated. Input and output are given and explained for two cases: a pointed code of 20 deg half angle at 15 deg angle of attack in a free stream with M sub infinite = 7, and a cone-ogive-cylinder at 10 deg angle of attack with M sub infinite = 2.86. A source listing of the computer code is provided

    Prediction of high speed propeller flow fields using a three-dimensional Euler analysis

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    To overcome the limitations of classical propeller theory, a computer program, NASPROP-E, was developed which solves for the flow field surrounding a multibladed propeller and axisymmetric nacelle combination using a finite difference method. The governing equations are the three dimensional unsteady Euler equations written in a cylindrical coordinate system. They are marched in time until a steady state solution is obtained. The Euler equations require no special treatment to model the blade work vorticity. The equations are solved using an implicit approximate factorization method. Numerical results are presented which have greatly increased the understanding of high speed propeller flow fields. Numerical results for swirl angle downstream of the propeller and propeller power coefficient are higher than experimental results. The radial variation of coefficient are higher than experimental results. The radial variation of swirl angle, however, is in reasonable agreement with the experimental results. The predicted variation of power coefficient with blade angle agrees very well with data

    Assessment of Omaha Public School\u27s Magnet School Objectives of Integration and Academic Excellence

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    Twenty-five sixth graders are working in a classroom, with several different groups involved in a plethora of activities. A large group is working on software that is displayed on a big-screen monitor which has been hooked up to a computer via a coaxial cable, another group is working on a worksheet generated from a computer, still another group is being helped by the teacher, and the remaining individuals are independently working. Every single student is involved and interested. Learning is taking place. Half the children are black and the other half are mostly white. This is the type of classroom that teachers envisioned for the future while in college. The kind that teachers can look around the room and feel proud of what is going on, feel good that they are part of it, and responsible for it

    Numerical simulation of viscous supersonic flow over a generic fighter configuration

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    A procedure is presented, as well as some results, to calculate the flow over a generic fighter configuration. A parabolized marching Navier-Stokes code is used to obtain the solution over a wing-canopy body. The flow conditions simulate supersonic cruise with a freestream Mach number of 2.169 and angles of attack of 4 and 10 deg. The body surface is considered to be an adiabatic wall and the flow is assumed to be turbulent for the given Reynolds number

    Use of a hyperbolic grid generation scheme in simulating supersonic viscous flow about three-dimensional winged configuration

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    The present paper describes a numerical mesh generation technique to be used with an implicit finite difference method for simulating visous supersonic flow about low-aspect-ratio wing body configurations using a single grid strategy. The computational domain is segmented into multiple regions, with borders located in supersonic areas to avoid the otherwise costly interfacing procedure between adjacent segments. The numerical procedure is applied to calculate the turbulent flow around the shuttle orbiter and a canard projectile at supersonic free stream Mach number

    The effects of single-gender math classroom activities on the achievement and behavior outcomes of fifth-grade girls and boys at a public elementary school

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    The purpose of this study was to examine single-gender schools and/or classes as a method of improving student achievement and gaining greater satisfaction in school. The paper will further examine the effects of single-gender classes on student achievement, the academic gender gap, and the attitudes of students and teachers. It will also look at the legal implications of such a practice. In addition, it will examine a variety of school district\u27s past methods and structures in order to implement a single-gender school or single-gender classes within a coed school including other programs within schools
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