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Ovalization of tubes under bending and compression

Description: An empirical equation has been developed that gives the approximate amount of ovalization for tubes under bending loads. Tests were made on tubes in the d/t range from 6 to 14, the latter d/t ratio being in the normal landing gear range. Within the range of the series of tests conducted, the increase in ovalization due to a compression load in combination with a bending load was very small. The bending load, being the principal factor in producing the ovalization, is a rather complex function of the bending moment, d/t ratio, cantilever length, and distance between opposite bearing faces. (author).
Date: March 1944
Creator: Demer, L. J. & Kavanaugh, E. S.
Partner: UNT Libraries Government Documents Department

Performance of axial-flow fan and compressor blades designed for high loadings

Description: Report presenting an investigation to determine the effects of loading on the performance of axial-flow fan and compressor blades in a test blower. Results regarding verification of the two-dimensional design data and effects of blade roughness are provided.
Date: February 1947
Creator: Bogdonoff, Seymour M. & Herrig, L. Joseph
Partner: UNT Libraries Government Documents Department

Theory of aircraft structural models subject to aerodynamic heating and external loads

Description: Report examining the problem of investigating the simultaneous effects of transient aerodynamic heating and external loads on aircraft structures for the purpose of determining the ability of the structure to withstand flight to supersonic speeds.
Date: September 1957
Creator: O'Sullivan, William J., Jr.
Partner: UNT Libraries Government Documents Department

Aerodynamic problems in the design of efficient propellers

Description: From General Analysis: "The purpose of part I of this paper is to show how the loading that gives the minimum induced energy loss can be obtained from rather elementary considerations and to present design charts from which such a plan form can be quickly obtained for any set of design conditions."
Date: August 1942
Creator: Feldman, Lewis
Partner: UNT Libraries Government Documents Department

Torsion of wing trusses at diving speeds

Description: The purpose of this report is to indicate what effect the distortion of a typical loaded wing truss will have upon the load distribution. The case of high angle of incidence may be dismissed immediately from consideration as the loads on the front and rear trusses are balanced, and consequently there will be little angular distortion. A given angular distortion will have the maximum effect upon load distribution in the region of the angle of no-lift, because the slope of the lift curve is highest here, and it is here that the greatest angular distortion will occur, because the load on the front truss acts downward while the load on the rear truss acts upward.
Date: 1921
Creator: Miller, Roy G.
Partner: UNT Libraries Government Documents Department

Low-speed yawed-rolling characteristics and other elastic properties of a pair of 26-inch-diameter, 12-ply-rating, type VII aircraft tires

Description: Report presenting an investigation of the low-speed cornering characteristics of two 26 x 6.6, type VII, 12-ply-rating tires under straight-yawed rolling over a range of inflation pressures and yaw angles for two vertical loads. Static testing and vibration testing were also carried out. The quantities measured included lateral or cornering force, drag force, torsional moment or self-alining torque, pneumatic caster, vertical tire deflection, lateral tire deflection, wheel torsion or yaw angle, rolling radius, and relaxation length.
Date: May 1956
Creator: Horne, Walter B.; Smiley, Robert F. & Stephenson, Bertrand H.
Partner: UNT Libraries Government Documents Department

The effect of high loading on landing technique and distance, with experimental data for the B-26 airplane

Description: Report presenting an analysis of the effect of wing loading of the landing flare, which indicated that it had an important effect on landing technique and distance. Results regarding the approach and flare path and ground run are provided.
Date: January 1945
Creator: O'Sullivan, William J., Jr.
Partner: UNT Libraries Government Documents Department

Method for calculating the aerodynamic loading on an oscillating finite wing in subsonic and sonic flow

Description: A method is presented for calculating the loading on a finite wing oscillating in subsonic or sonic flow. The method is applicable to any plan form and may be used for determining the loading on deformed wings. The procedure is approximate and requires numerical integration over the wing surface.
Date: March 14, 1956
Creator: Runyan, Harry L. & Woolston, Donald S.
Partner: UNT Libraries Government Documents Department

Theoretical symmetric span loading at subsonic speeds for wings having arbitrary plan form

Description: A method is shown by which the symmetric span loading for a certain class of wings can be simply found. The geometry of these wings is limited only to the extent that they must have symmetry about the root chord, must have a straight quarter-chord line over the semispan, and must have no discontinuities in twist. A procedure is shown for finding the lift-curve slope, pitching moment, center of lift, and induced drag from the span load distribution. A method of accounting for the effects of Mach number and for changes in section lift-curve slope is also given. Charts are presented which give directly the characteristics of many wings. Other charts are presented which reduce the problem of finding the symmetric loading on all wings falling within the prescribed limits to the solution of not more than four simultaneous equations. The loadings and wing characteristics predicted by the theory are compared to those given by other theories and by experiment. It is concluded that the results given by the subject theory are satisfactory. The theory is applied to a number of wings to exhibit the effects of such variables as sweep, aspect ratio, taper, and twist. The results are compared and conclusions drawn as to the relative effects of these variables.
Date: 1948
Creator: DeYoung, John & Harper, Charles W.
Partner: UNT Libraries Government Documents Department

Generalized performance selection charts for single-engine pursuit airplanes

Description: Report presenting an investigation of the effect of wing loading, power loading, and aspect ratio on the performance of pursuit airplanes. The study is based on data combined from specifications, wind-tunnel, and flight tests of various airplanes and presented in graphs.
Date: February 1943
Creator: Ivey, H. Reese; Stickle, George W. & Brevoort, Maurice J.
Partner: UNT Libraries Government Documents Department

Flight measurements and calculations of wing loads and load distributions at subsonic, transonic, and supersonic speeds

Description: From Summary: "Presented in this report is a summary of local and net angle-of-attack wing-panel loads measured in flight on six airplanes. In addition, a comparison of these loads measured in flight with calculations based on simple theory is presented."
Date: July 2, 1957
Creator: Malvestudo, Frank S.; Cooney, Thomas V. & Keener, Earl R.
Partner: UNT Libraries Government Documents Department

The effect of spanwise mass distribution upon the spin characteristics of airplanes as determined by model tests conducted in the free-spinning wind tunnel

Description: Report presenting an investigation to determine whether the difference in the spanwise loading of the two types of aircraft were responsible for the differences in spin characteristics, particularly in regards to angle of attack.
Date: August 1942
Creator: Kamm, Robert W.
Partner: UNT Libraries Government Documents Department

Investigation of the variation of maximum lift for a pitching airplane model and comparison with flight results

Description: Report presenting the use of an apparatus utilizing a pitching airplane model to determine maximum wing loads as a function of the rate of change of angle of attack. A wind-tunnel and flight investigation were carried out and the results were compared.
Date: October 1948
Creator: Harper, Paul W. & Flanigan, Roy E.
Partner: UNT Libraries Government Documents Department

Metabolic Engineering in Plants to Control Source/sink Relationship and Biomass Distribution

Description: Traditional methods like pruning and breeding have historically been used in crop production to divert photoassimilates to harvested organs, but molecular biotechnology is now poised to significantly increase yield by manipulating resource partitioning. It was hypothesized that metabolic engineering in targeted sink tissues can favor resource partitioning to increase harvest. Raffinose Family Oligosaccharides (RFOs) are naturally occurring oligosaccharides that are widespread in plants and are responsible for carbon transport, storage and protection against cold and drought stress. Transgenic plants (GRS47, GRS63) were engineered to generate and transport more RFOs through the phloem than the wild type plants. The transgenic lines produced more RFOs and the RFOs were also detected in their phloem exudates. But the 14CO2 labeling and subsequent thin layer chromatography analysis showed that the RFOs were most likely sequestered in an inactive pool and accumulate over time. Crossing GRS47 and GRS63 lines with MIPS1 plants (that produces more myo-inositol, a substrate in the RFO biosynthetic pathway) did not significantly increase the RFOs in the crossed lines. For future manipulation of RFO degradation in sink organs, the roles of the endogenous α-galactosidases were analyzed. The alkaline α-galactosidases (AtSIP1 and AtSIP2 in Arabidopsis) are most likely responsible for digesting RFOs in the cytoplasm and may influence the ability to manipulate RFO levels in engineered plants. Atsip1/2 (AtSIP1/AtSIP2 double-knockout plants) were generated and phenotypically characterized based on seed germination patterns, flowering time, and sugar content to observe the impact on RFO sugar levels. The observations and analysis from these lines provide a basis for further insight in the manipulation of resource allocation between source and sink tissues in plants for future research.
Date: August 2013
Creator: Lahiri, Ipsita
Partner: UNT Libraries

Wake surveys in the slipstream of a full-scale supersonic-type three-blade propeller at Mach numbers to 0.96

Description: Report presenting an investigation of the thrust loading by wake surveys in the slipstream of a full-scale supersonic-type three-blade propeller (the Curtiss-Wright 109622) that was conducted in the transonic tunnel. Integrated-thrust coefficient values were found to be in good agreement with the force data. Results regarding thrust loading at constant advance ratios, at advance ratios for maximum efficiency, and lift-coefficient distribution are also provided.
Date: October 30, 1953
Creator: Swihart, John M. & Norton, Harry T., Jr.
Partner: UNT Libraries Government Documents Department

Water-landing investigation of a model having heavy beam loadings and 0 degrees angle of dead rise

Description: Report presenting testing of a model with heavy beam loadings and an angle of dead rise of 0 degrees subjected to smooth-water impacts at a range of fixed trims and flight-path angles. Results regarding the time histories of horizontal and vertical displacements, vertical velocity, vertical acceleration, and pitching moment are provided.
Date: April 1951
Creator: McArver, A. Ethelda
Partner: UNT Libraries Government Documents Department

A deflection formula for single-span beams of constant section subjected to combined axial and transverse loads

Description: In this paper there is presented a deflection formula for single-span beams of constant section subjected to combined axial and transverse loads of the types commonly encountered in airplane design. The form of the equation is obtainable by dimensional analysis. Tables and curves of the non dimensional coefficients are appended to facilitate the use of the formula. The equation is applied to the determination of the spring constant of a beam. Tables and curves are presented to show the variation of the spring constant with changes in the axial load and position along the beam.
Date: September 1935
Creator: Burke, Walter F.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation at high subsonic speeds of the effects of wing-mounted external stores on the loading and aerodynamic characteristics in pitch of a 45 degree sweptback wing combined with a fuselage

Description: Report presenting an investigation of the effect of wing-mounted external stores on the loading and aerodynamic characteristics in pitch of a 45 degree sweptback wing combined with a fuselage. Store arrangements investigated consisted of stores mounted at the wing tips, stores mounted inboard on the wing undersurface at 46-percent semispan, and stores in both the tip and inboard locations.
Date: March 23, 1954
Creator: Silvers, H. Norman & King, Thomas J., Jr.
Partner: UNT Libraries Government Documents Department

Manipulating Sucrose Proton Symporters to Understand Phloem Loading

Description: Phloem vascular tissues transport sugars synthesized by photosynthesis in mature leaves by a process called phloem loading in source tissues and unloading in sink tissues. Phloem loading in source leaves is catalyzed by Suc/H+ symporters (SUTs) which are energized by proton motive force. In Arabidopsis the principal and perhaps exclusive SUT catalyzing phloem loading is AtSUC2. In mutant plants harboring a T-DNA insertion in each of the functional SUT-family members, only Atsuc2 mutants demonstrate overtly debilitated phloem transport. Analysis of a mutant allele (Atsuc2-4) of AtSUC2 with a T-DNA insertion in the second intron showed severely stunted phenotype similar to previously analyzed Atsuc2 null alleles. However unlike previous alleles Atsuc2-4 produced viable seeds. Analysis of phloem specific promoters showed that promoter expression was regulated by Suc concentration. Unlike AtSUC2p, heterologous promoter CoYMVp was not repressed under high Suc conc. Further analysis was conducted using CoYMVp to test the capacity of diverse clades in SUT-gene family for transferring Suc in planta in Atsuc2 - / - mutant background. AtSUC1 and ZmSUT1 from maize complemented Atsuc2 mutant plants to the highest level compared to all other transporters. Over-expression of the above SUTs in phloem showed enhanced Suc loading and transport, but against expectations, plants were stunted. The implications of SUT over-expression to enhance phloem transport and loading are discussed and how it induces a perception of phosphate imbalance is presented.
Date: August 2013
Creator: Dasgupta, Kasturi
Partner: UNT Libraries

Wing-load measurements at supersonic speeds of the Douglas D-558-II research airplane

Description: From Summary: "Flight measurements of the aerodynamic wing loads on the D-558-II airplane have been made in the Mach number range from 1.0 to 2.0. Nonlinear wing-panel characteristics occurred with variations in angle of attack. These nonlinear characteristics were apparent primarily at the lower supersonic speeds."
Date: March 30, 1955
Creator: Robinson, Glenn H.; Cothren, George E., Jr. & Pembo, Chris
Partner: UNT Libraries Government Documents Department

A wind-tunnel investigation of the wing loads due to deflected inboard ailerons on a 45 degree sweptback wing at transonic speeds

Description: Report presenting an investigation of the effects of deflected inboard ailerons on the wing loads of a 45 degree sweptback wing-body combination. The model had a wing of aspect ratio 3, a taper ratio of 0.2, and NACA 65A004 airfoil sections. Results regarding chordwise pressure distributions, the effect of ailerons on wing section loadings, the effect of aileron on wing loading, and the effects of a deflected aileron on opposite-wing loading are presented.
Date: July 21, 1958
Creator: Heath, Atwood R., Jr. & Igoe, Ann W.
Partner: UNT Libraries Government Documents Department

Aerodynamic loading characteristics of a wing-fuselage combination having a wing of 45 degrees sweepback measured in the Langley 8-foot transonic tunnel

Description: Report presenting an investigation of the aerodynamic loading characteristics of a wing-fuselage combination in the slotted test section of the transonic tunnel. The test was part of a systematic investigation of the effects of varying the amount of sweepback on wings in order to determine their suitability for transonic flight. Results regarding span load characteristics, normal-force characteristics, wing-tip angle of twist, spanwise distribution of section pitching-moment coefficient, pitching-moment characteristics, and fuselage characteristics in presence of wing are provided.
Date: May 19, 1952
Creator: Loving, Donald L. & Williams, Claude V.
Partner: UNT Libraries Government Documents Department

Aerodynamic loads on an external store adjacent to a 45 degree sweptback wing at Mach numbers from 0.70 to 1.96, including an evaluation of techniques used

Description: From Summary: "Aerodynamic forces and moments have been obtained in the Langley 9- by 12-inch blowdown tunnel on an external store and on a 45 degree swept-back wing-body combination measured separately at Mach numbers from 0.70 to 1.96. The wing was cantilevered and had an aspect ratio of 4.0; the store was independently sting-mounted and had a Douglas Aircraft Co. (DAC) store shape. The angle of attack range was from -3 degrees to 12 degrees and the Reynolds number (based on wing mean aerodynamic chord) varied from 1.2 x10(6) to 1.7 x 10(6). Wing-body transonic forces and moments have been compared with data of a geometrically similar full-scale model tested in the Langley 16-foot and 8-foot transonic tunnels in order to aid in the evaluation of transonic-tunnel interference."
Date: November 15, 1955
Creator: Guy, Lawrence D. & Hadaway, William M.
Partner: UNT Libraries Government Documents Department