From Introduction: "For the analysis reported herein, the same hypothetical 12-stage compressor discussed in reference 6 was chosen, and the effects of inlet-stage stall characteristics and stage interactions were estimated by arbitrary adjustment of the stall characteristics and stage interactions were estimated by arbitrary adjustment of the stalled characteristics of the individual stages."
From Summary: "A limited investigation of a 1/24-scale dynamically similar model of the Navy Bureau of Aeronautics DR-77 design was conducted in Langley tank no. 2 to determine the calm-water take-off and the rough-water landing characteristics of the design with particular regard to the take-off resistance and the landing accelerations. During the take-off tests, resistance, trim, and rise were measured and photographs were taken to study spray. During the landing tests, motion-picture records and normal-acceleration records were obtained."
Report presenting the incremental lift and pitching moments produced by 20-percent-chord split flaps of various spans at various spanwise positions on two 45 degree sweptback wings of aspect ratio 8.02 as obtained by pressure-distribution testing. Inboard flaps were found to be far more effective in producing lift than outboard flaps. Results regarding spanwise loading and pitching moment are provided.
Report presenting an investigation at Mach numbers 1.88 and 2.93 to determine the performance characteristics of a conical external-compression side inlet model with a swept-leading-edge boundary-layer-removal scoop. Two other boundary-layer-removal systems were also investigated, which used a deflection wedge and cowl-lip scoops. Results regarding swept-scoop inlets, scoop performance, alternative boundary-layer-removal systems at Mach 1.88, and a comparison of the boundary layer removal systems are provided.
An empirical relation is presented which represents a boundary between no vacuum sparking and possible vacuum sparking. Metal electrodes and r.f. or d.c. voltages are used. The criterion fits several orders of surface gradient, voltage, gap, and frequency. Current due to field emission is considered necessary for sparking but in addition, energetic particles are required to initiate a cascade process which increases the field emission currents to the point of sparking. An elementary cascade process is outlined, but the data upon which it is based is not fully stated.
Abstract: "Differential thermal-expansion effects in brazed joints involving Type 310 stainless steel and GE-62 brazing alloy were investigated. The work included dilation and modulus-of-elasticity measurements using homogenous cast specimens and observations on bimetallic cantilevers made of the two constituents. No anomalies were found, although there were irregularities in the expansion of the brazing alloy which were ascribed to a solubility phenomenon. The elastic modulus of the brazing alloy was determined. Cantilever deflections with temperature and with load were measured, and the results were interpreted using equations which treat the specimens as true bimetals consisting of two homogeneous components. The difference in thermal-expansion coefficients obtained in this way from the temperature-deflection data was consistent with the dilation measurements. The load measurements yielded an average elastic modulus for the bimetal which was about two-thirds of what would have been expected from knowledge of the components. This discrepancy probably arose from porosity which was observed in the braze components."
The investigation reported in this document concerns itself with studies of the mechanism of corrosion on the exterior of process tubes and with studies of the protective qualities of anodic films which might prevent corrosion on the exterior of process tubes. Sections of process tubing coated with Aqua-Dag, a colloidal graphite suspension, were included in these tests for comparison purposes as present operating procedures call for the application of Aqua-Dag to the exterior of process tubes for lubrication purposes during the charging of tubes into the piles.
Report presenting an investigation to develop screech instrumentation and study the mechanism of screech in a simulated afterburner. Results regarding the screech mechanism, effect of system variables on screech, speculation regarding screech mechanism, and suggested techniques for elimination or control of screech are provided.
Report presenting an investigation using a number of systematic configuration modifications to an afterburner to determine their effect on screech characteristics. The modifications included changes in the afterburner diffuser, the fuel system, and the flame holder. Results regarding some of the characteristics of screeching combustion, effect of diffuser flow conditions, and effect of fuel system and flame holder are provided.
"Three rocket-propelled buffet-research models have been flight tested to determine the buffeting characteristics of a swept-wing- airplane configuration with the horizontal tail operating near the wing wake. The models consisted of parabolic bodies having 45 deg sweptback wings of aspect ratio 3.56, at aspect ratio of 0.3, NACA 64A007 airfoil sections, and tail surfaces of geometry and section identical to the wings. Two tests were conducted with the horizontal tail located in the wing chord plane with fixed incidence angles of -1.5deg on one model and 0deg on the other model" (p. 1).
Memorandum presenting an eight-stage high-pressure-ratio axial-flow compressor designed for use as a research unit in which the problems associated with design and off-design performance of transonic stages combined with highly loaded subsonic stages could be studied. The report discusses the design procedure and presents the experimentally determined overall performance of the compressor.
Report presenting an investigation to determine, by experiments within the scope of air-entry-hole geometry, design criteria for tubular combustors with good low-pressure performance. Combustion efficiency, operable fuel-air-ratio and pressure ranges, and minimum ignition pressures were determined for several combustor configurations at conditions simulating a 5.2-pressure-ratio turbojet engine operating at 85 percent of rated rotor speed, a flight Mach number of 0.6, and altitudes from 56,000 to 80,000 feet.
Report presenting the design and performance of a turbine with nontwisted rotor blades designed to drive a high-speed, high-specific-mass-flow supersonic compressor. Results regarding turbine performance, entrance Mach number, radial temperature surveys, and loading are provided.
This technical report is a summary of unclassified theoretical work on propagation of one-dimensional shock waves and on the propagation of spherical shock waves in gases.
Various organizations in the Biophysics Section of the Radiological Sciences Department participated in evaluating local radioactive particle fallout as influenced by the nuclear explosions at the Nevada Proving Grounds during the early part of 1953. Data collected from approximately 50 air monitoring stations operated by the Regional Survey forces were used to determine the trend of radioactive particle concentrations in the atmosphere between March and June. These measurements were supplemented with the findings of associated organizations in the Biophysics Section during and immediately after the peak influx on May 26.
In obtaining the results reported here a double focusing magnetic type spectrometer was used. Momentum spread was about 1%, and in most cases 2560 counts per point were taken. An end window Geiger tube was used as a detector. The window was of mica with areal density of 1.6 mg/cm2.
Report presenting an investigation of the effects of adding leading-edge roughness to the surfaces of an unswept, untapered, 6-percent-thick, circular-arc-airfoil wing equipped with a full-span, 0.2-chord, plain, trailing-edge aileron. Results regarding the rolling-effectiveness data, addition of roughness on a wing, and variation of drag coefficient are provided.
Flight-test measurements, related analytical studies, and corresponding pilots' opinions of the speed stability of tandem-rotor helicopter are presented. An undesirable instability, evidenced by rearward stick motion with increasing forward speed at constant power, is indicated to be caused by variations with speed of the front-rotor downwash at the rear rotor. An analytical expression for predicting changes in speed stability caused by changes in rotor geometry is derived and constants for use with the analytical expression are presented in chart form. Means for improving stability with speed are studied both analytically and experimentally. The test results also give some information as to the flow conditions at the rear rotor.
The susceptibleness of certain "ceramic" substances to extreme radiation damage (such as that observed in graphite) as indicated by changes in dimensions and heat content is discussed in terms of the experimental evidence which is available.
Two xenon extraction runs were made this month. It appears that a small design change in Trap #2 will be necessary so that a dry ice-trichloroethylene slurry can be used for coolant rather than liquid freon. For each of the runs this month the enriched generator was exposed for four hours in the est pile operating at 100 watts. A period of eight hours for cooling and xenon builidup was allowed before the collection and separation runs were started.
In this report, a brief discussion is given for each of the following activities under study during this period: xenon generator; C{sup 12} cross sections; critical mass problems (for process vessels in Bldg. 231); neutron beam catcher design; neutron diffraction spectrometer; beta spectrometer; hollow slug program; instrumentation; blackness corrections; exponential pile measurements with small slug size; critical lattice experiments; lattice theory; and radiation damage.
Memorandum presenting the aerodynamic characteristics of the NACA 0010-1.50 40/1.051 airfoil section as determined from wind-tunnel tests at Mach numbers from 0.3 to 0.9. The results are compared with those of the effects of leading-edge-radius variation from 0.27 to 1.10 percent of the chord on the characteristics of a 10-percent-thick, symmetrical airfoil section at high subsonic Mach numbers. Results regarding the lift characteristics, drag characteristics, and pitching-moment characteristics are provided.
Report presenting an investigation in the low-turbulence pressure tunnel to determine the lift, drag, and pitching-moment characteristics of two unswept wings, one with airfoil sections designed for high maximum lift at low speeds (NACA 2-006) and one with NACA 65A006 airfoil sections. Results regarding lift and pitching-moment, effects of roughness, drag, and wings with flaps are provided for high- and low-speed performance.
Report presenting measurements of wing loads made on the left wing of the Bell X-1 research airplane. Data are presented within a wing-panel normal-force coefficient and Mach number range. Results regarding span load distributions, wing-panel aerodynamic characteristics, and wing-to-fuselage carry over are provided.
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