Latest content added for UNT Digital Library Collection: National Advisory Committee for Aeronautics (NACA)http://digital.library.unt.edu/explore/collections/NACA/browse/2015-02-26T16:50:55-06:00UNT LibrariesThis is a custom feed for browsing UNT Digital Library Collection: National Advisory Committee for Aeronautics (NACA)Some Recent Contributions to the Study of Transition and Turbulent Boundary Layers2015-02-26T16:50:55-06:00http://digital.library.unt.edu/ark:/67531/metadc172454/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172454/"><img alt="Some Recent Contributions to the Study of Transition and Turbulent Boundary Layers" title="Some Recent Contributions to the Study of Transition and Turbulent Boundary Layers" src="http://digital.library.unt.edu/ark:/67531/metadc172454/thumbnail/"/></a></p><p>None</p>Considerations of the Total Drag of Supersonic Airfoil Sections2015-02-26T16:50:55-06:00http://digital.library.unt.edu/ark:/67531/metadc172466/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172466/"><img alt="Considerations of the Total Drag of Supersonic Airfoil Sections" title="Considerations of the Total Drag of Supersonic Airfoil Sections" src="http://digital.library.unt.edu/ark:/67531/metadc172466/thumbnail/"/></a></p><p>The results of calculations of the viscous and pressure drags of some two-dimensional supersonic airfoils at zero lift are presented. The results indicate that inclusion of viscous drag alters many previous results regarding the desirability of certain airfoil shapes for securing low drags at supersonic speeds. At certain Reynolds and Mach numbers, for instance, a circular-arc airfoil may theoretically have less drag than the previously advocated symmetrical wedge-shape profile; although under different conditions, the circular-arc airfoil may have a higher drag.</p>Two-Dimensional Irrotational Transonic Flows of a Compressible Fluid2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172480/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172480/"><img alt="Two-Dimensional Irrotational Transonic Flows of a Compressible Fluid" title="Two-Dimensional Irrotational Transonic Flows of a Compressible Fluid" src="http://digital.library.unt.edu/ark:/67531/metadc172480/thumbnail/"/></a></p><p>The methods of NACA TN No. 995 have been slightly modified and extended in include flows with circulation by considering the alteration of the singularities of the incompressible solution due to the presence of the hypergeometric functions in the analytic continuation of the solution. It was found that for finite Mach numbers the only case in which the nature of the singularity can remain unchanged is for a ratio of specific heats equal to -1. From a study of two particular flows it seems that the effect of geometry cannot be neglected, and the conventional "pressure-correction" formulas are not valid, even in the subsonic region if the body is thick, especially if there is a supersonic region in the flow.</p>Bending Tests of Metal Monocoque Fuselage Construction2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172433/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172433/"><img alt="Bending Tests of Metal Monocoque Fuselage Construction" title="Bending Tests of Metal Monocoque Fuselage Construction" src="http://digital.library.unt.edu/ark:/67531/metadc172433/thumbnail/"/></a></p><p>Study of the bending stress in smooth skin, aluminum alloy, true monocoque fuselage sections of varying ratio of diameter to thickness.</p>Performance of B. M. W. 185-Horsepower Airplane Engine2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172405/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172405/"><img alt="Performance of B. M. W. 185-Horsepower Airplane Engine" title="Performance of B. M. W. 185-Horsepower Airplane Engine" src="http://digital.library.unt.edu/ark:/67531/metadc172405/thumbnail/"/></a></p><p>None</p>Aerodynamic Investigation of a Cup Anemometer2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172432/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172432/"><img alt="Aerodynamic Investigation of a Cup Anemometer" title="Aerodynamic Investigation of a Cup Anemometer" src="http://digital.library.unt.edu/ark:/67531/metadc172432/thumbnail/"/></a></p><p>Results of an investigation wherein the change of the normal force coefficient with Reynolds Number was obtained statically for a 15.5-centimeter hemispherical cup.</p>Tables and Charts of Flow Parameters Across Oblique Shocks2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172508/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172508/"><img alt="Tables and Charts of Flow Parameters Across Oblique Shocks" title="Tables and Charts of Flow Parameters Across Oblique Shocks" src="http://digital.library.unt.edu/ark:/67531/metadc172508/thumbnail/"/></a></p><p>Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy.</p>A Comparison of Theory and Experiment for High-Speed Free-Molecule Flow2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172515/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172515/"><img alt="A Comparison of Theory and Experiment for High-Speed Free-Molecule Flow" title="A Comparison of Theory and Experiment for High-Speed Free-Molecule Flow" src="http://digital.library.unt.edu/ark:/67531/metadc172515/thumbnail/"/></a></p><p>Comparison of free-molecule-flow theory with the results of wind-tunnel tests performed to determine the drag and temperature-rise characteristics of a transverse circular cylinder.</p>Two-Dimensional Subsonic Compressible Flows Past Arbitrary Bodies by the Variational Method2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc172521/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc172521/"><img alt="Two-Dimensional Subsonic Compressible Flows Past Arbitrary Bodies by the Variational Method" title="Two-Dimensional Subsonic Compressible Flows Past Arbitrary Bodies by the Variational Method" src="http://digital.library.unt.edu/ark:/67531/metadc172521/thumbnail/"/></a></p><p>Instead of solving the nonlinear differential equation which governs the compressible flow, an approximate method of solution by means of the variational method is used. The general problem of steady irrotational flow past an arbitrary body is formulated. Two examples were carried out, namely, the flow past a circular cylinder and the flow past a thin curved surface. The variational method yields results of velocity and pressure distributions which compare excellently with those found by existing methods. These results indicate that the variational method will yield good approximate solution for flow past both thick and thin bodies at both high and low Mach numbers.</p>Average Outside-Surface Heat-Transfer Coefficients and Velocity Distributions for Heated and Cooled Impulse Turbine Blades in Static Cascades2014-09-25T20:32:43-05:00http://digital.library.unt.edu/ark:/67531/metadc100824/<p><a href="http://digital.library.unt.edu/ark:/67531/metadc100824/"><img alt="Average Outside-Surface Heat-Transfer Coefficients and Velocity Distributions for Heated and Cooled Impulse Turbine Blades in Static Cascades" title="Average Outside-Surface Heat-Transfer Coefficients and Velocity Distributions for Heated and Cooled Impulse Turbine Blades in Static Cascades" src="http://digital.library.unt.edu/ark:/67531/metadc100824/thumbnail/"/></a></p><p>Heat-transfer investigation conducted on cooled as well heated impulse-type turbine blades in a static cascade to determine the effect of direction of heat flow on convective heat-transfer coefficients.</p>