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On subsonic compressible flows by a method of correspondence II : application of methods to studies of flow with circulation about a circular cylinder

Description: A general method for studying the flow of a compressible fluid around a closed body was discussed in Part I of this report. Here, application is made to the specific case in which the linearized equation of state is used. For a given incompressible flow around a specific profile, a corresponding compressible flow is found. The flow at infinity remains unchanged. Detailed studies are made of the flow with circulation around a unit circle, and velocity distributions are found for a wide range of Mach number and angle of attack. Comparisons are made with other methods.
Date: April 1947
Creator: Gelbart, Abe & Bartnoff, Shepard
Partner: UNT Libraries Government Documents Department

On subsonic compressible flows by a method of correspondence I - methods for obtaining subsonic circulatory compressible flows about two-dimensional bodies

Description: From Summary: "By means of the general solutions of the hodograph equations for compressible fluids, certain solutions corresponding to solutions of the hodograph equations of an incompressible fluid are used to find flow patterns of compressible fluids. When the adiabatic equation of state is used, only a general method is outlined. The method appears to lead to the solution of the problem of subsonic flows with circulation around arbitrary bodies, as the method of Theodorsen does for incompressible fluids."
Date: March 1947
Creator: Gelbart, Abe
Partner: UNT Libraries Government Documents Department

On the Continuation of a Potential Gas Flow Across the Sonic Line

Description: "Simple, sufficient conditions are given under which a two-dimensional steady compressible flow can be continued across the line of Mach number 1 as a continuous supersonic flow. Methods for the actual computation of the flow are described. The problem is of importance in the theory of transonic flows past airfoils" (p. 1).
Date: April 1950
Creator: Bers, Lipman
Partner: UNT Libraries Government Documents Department

Velocity Distribution on Wing Sections of Arbitrary Shape in Compressible Potential Flow 3: Circulatory Flows Obeying the Simplified Density-Speed Relation

Description: "The method of computing velocity and pressure distributions along wing profiles under the assumption of the simplified density-speed relation, outlined in NACA Technical Note 1006, is extended to the case of a nonsymmetrical profile and a flow with circulation. The shape of the profile, the speed of the undisturbed flow, and a parameter determining the angle of attack may be prescribed. The problem is reduced to a nonlinear integral equation which can be solved numerically by an iteration method" (p. 1).
Date: March 1950
Creator: Bers, Lipman
Partner: UNT Libraries Government Documents Department

A method of computing subsonic flows around given airfoils

Description: From Summary: "An extremely simple computational method is established for obtaining circulatory flows around given bodies to a high degree of accuracy for flows satisfying the linear pressure and specific-volume equation of state. The method depends not on an integral equation but on the transformation from the holograph to the physical plane involving the determination of an arbitrary analytic function. The determination of the arbitrary analytic function by elementary means results in a close approximation of the given body."
Date: March 1950
Creator: Gelbart, Abe & Resch, Daniel
Partner: UNT Libraries Government Documents Department

Thermodynamics and Kinetics in Hydrate Systems

Description: From Introduction and Summary: "This report presents the results of one year of experimental work performed under an Office of Saline Water Grant to study various aspects of the hydrate process for demineralizing sea water. Work is continuing on all phases of the subjects reported here."
Date: January 1965
Creator: Kass, Jeffrey R.; Fernandez-Martin, Remigio; Embpie, Howard L. & Barduhn, Allen J.
Partner: UNT Libraries Government Documents Department

Investigation of Stresses Due to Thermal Gradients in Typical Aircraft Structures

Description: Memorandum presenting an investigation of a series of five 75S-T6 aluminum-alloy elementary skin and spar-cap combinations with skin varying from 0.051 to 0.500 inch in thickness to determine the temperature and stress gradients resulting from the application of heat to the surface. The data are presented in the form of tables of the measured temperatures and stresses calculated from the measured strains.
Date: January 25, 1952
Creator: Barzelay, Martin E. & Boison, James C.
Partner: UNT Libraries Government Documents Department

Interface Thermal Conductance of Twenty-Seven Riveted Aircraft Joints

Description: Note presenting testing of twenty-seven structural joint specimens of 2024-T3 and 2024-T4 aluminum alloy consisting of a T-stringer riveted to a 10- by 10-inch skin surface under simulated aerodynamic heating with no external loading applied. Rivet size and pitch were found to influence the conductance but the rivet materials tested had no observable effect.
Date: July 1957
Creator: Barzelay, Martin E. & Holloway, George F.
Partner: UNT Libraries Government Documents Department

Effect of an Interface on Transient Temperature Distribution in Composite Aircraft Joints

Description: Note presenting testing of geometrically related structural joints representing typical skin-stringer cross sections under radiant heating to simulate the effects of aerodynamic heating. The presence of an interface was found to have a significant effect on the temperature distribution in all geometries tested and thus must be considered in temperature calculations. Interface conductance values were computed for each of the 15 fabricated specimens.
Date: April 1957
Creator: Barzelay, Martin E. & Holloway, George F.
Partner: UNT Libraries Government Documents Department

Parallel phase model : a programming model for high-end parallel machines with manycores.

Description: This paper presents a parallel programming model, Parallel Phase Model (PPM), for next-generation high-end parallel machines based on a distributed memory architecture consisting of a networked cluster of nodes with a large number of cores on each node. PPM has a unified high-level programming abstraction that facilitates the design and implementation of parallel algorithms to exploit both the parallelism of the many cores and the parallelism at the cluster level. The programming abstraction will be suitable for expressing both fine-grained and coarse-grained parallelism. It includes a few high-level parallel programming language constructs that can be added as an extension to an existing (sequential or parallel) programming language such as C; and the implementation of PPM also includes a light-weight runtime library that runs on top of an existing network communication software layer (e.g. MPI). Design philosophy of PPM and details of the programming abstraction are also presented. Several unstructured applications that inherently require high-volume random fine-grained data accesses have been implemented in PPM with very promising results.
Date: April 1, 2009
Creator: Wu, Junfeng (Syracuse University, Syracuse, NY); Wen, Zhaofang; Heroux, Michael Allen & Brightwell, Ronald Brian
Partner: UNT Libraries Government Documents Department

Electroabsorption and Transport Measurements and Modeling Research in Amorphous Silicon Based Solar Cells; Annual Report; 24 March 1999-23 March 2000

Description: We have performed computer calculations to explore effects of the p/i interface on the open-circuit voltage in a-Si:H based pin solar cells. The principal conclusions are that interface limitation can occur for values of VOC significantly below the built-in potential of VBI of a cell, and that the effects can be understood in terms of thermionic emission of electrons from the intrinsic layer into the p-layer. We compare measurements of VOC and electroabsorption estimates of VBI with the model calculations. We conclude that p/i interface limitation is important for current a-Si:H based cells, and that the conduction band offset between the p and i layers is as important as the built-in potential for future improvements to VOC.
Date: February 14, 2001
Creator: Schiff, E.A.; Kopidakis, N.; Lyou, J.; Rane, S.; Yuan, Q. & Zhu, K. (Syracuse University)
Partner: UNT Libraries Government Documents Department

Effect of Pressure on Thermal Conductance of Contact Joints

Description: Technical note presenting tests conducted to determine the factors influencing the thermal conductance across the interface formed between stationary plane surfaces of 75S-T6 aluminum-alloy and AISI Type 416 stainless-steel blocks. The types of joints investigated included bare metal-to-metal contact, contact surfaces separated by a good conductor (brass), and contact surfaces separated by a thin sheet of insulation (asbestos). Results regarding the effect of surface roughness, pressure, mean interface temperature, temperature drop, sandwich material, time as a factor in conductance, and effect of test reassembly and interface matching are provided.
Date: May 1955
Creator: Barzelay, Martin E.; Tong, Kin Nee & Holloway, George F.
Partner: UNT Libraries Government Documents Department

Research on High-Bandgap Materials and Amorphous Silicon-Based Solar Cells, Final Technical Report, 15 May 1994-15 January 1998

Description: This report describes work performed by Syracuse University under this subcontract. Researchers developed a technique based on electroabsorption measurements for obtaining quantitative estimates of the built-in potential Vbi in a-Si:H-based heterostructure solar cells incorporating microcrystalline or a-SiC:H p layers. Using this new electroabsorption technique, researchers confirmed previous estimates of Vbi {yields} 1.0 V in a-Si:H solar cells with ''conventional'' intrinsic layers and either microcrystalline or a-SiC:H p layers. Researchers also explored the recent claim that light-soaking of a-Si:H substantially changes the polarized electroabsorption associated with interband optical transitions (and hence, not defect transitions). Researchers confirmed measurements of improved (5') hole drift mobilities in some specially prepared a-Si:H samples. Disturbingly, solar cells made with such materials did not show improved efficiencies. Researchers significantly clarified the relationship of ambipolar diffusion-length measurements to hole drift mobilities in a-Si:H, and have shown that the photocapacitance measurements can be interpreted in terms of hole drift mobilities in amorphous silicon. They also completed a survey of thin BP:H and BPC:H films prepared by plasma deposition using phosphine, diborane, trimethylboron, and hydrogen as precursor gases.
Date: December 28, 1998
Creator: Schiff, E. A.; Gu, Q.; Jiang, L.; Lyou, J.; Nurdjaja, I. & Rao, P. (Department of Physics, Syracuse University)
Partner: UNT Libraries Government Documents Department