19 Matching Results

Search Results

Investigation of Pressure Losses in Several Turbosupercharger Nozzle Hoses

Description: Memorandum presenting surveys of the impact pressure of the flow to obtain information for determining pressure losses in four different turbosupercharger nozzle boxes. The data indicated substantial differences in total head loss among the boxes and the existence of sharply defined high-loss regions in portions of the nozzle annulus.
Date: February 11, 1947
Creator: Lord, Albert M. & Donnola, Joseph
Partner: UNT Libraries Government Documents Department

Calculation of Wing Bending Moments and Tail Loads Resulting from the Jettison of Wing Tips During a Symmetrical Pull-Up

Description: A preliminary analytical investigation was made to determine the feasibility of the basic idea of controlled failure points as safety valves for the primary airplane structure. The present analysis considers the possibilities of the breakable wing tip which, in failing as a weak link, would relieve the bending moments on the wing structure. The analysis was carried out by computing the time histories of the wing and stabilizer angle of attack in a 10g pull-up for an XF8F airplane with tips fixed and comparing the results with those for the same maneuver, that is, elevator motion but with tips jettisoned at 8g. The calculations indicate that the increased stability accompanying the loss of the wing tips reduces the bending moment an additional amount above that which would be expected from the initial loss in lift and the inboard shift in load. The vortex shed when the tips are lost may induce a transient load requiring that the tail be made stronger than otherwise.
Date: December 11, 1947
Creator: Boshar, John
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines I - Effects of Addition of Fins to Blade Tips and Rotor, Admission of Cooling Air Through Part of Nozzles, and Change in Thermal Conductivity of Turbine Components

Description: An analysis was developed for calculating the radial temperature distribution in a gas turbine with only the temperatures of the gas and the cooling air and the surface heat-transfer coefficient known. This analysis was applied to determine the temperatures of a complete wheel of a conventional single-stage impulse exhaust-gas turbine. The temperatures were first calculated for the case of the turbine operating at design conditions of speed, gas flow, etc. and with only the customary cooling arising from exposure of the outer blade flange and one face of the rotor to the air. Calculations were next made for the case of fins applied to the outer blade flange and the rotor. Finally the effects of using part of the nozzles (from 0 to 40 percent) for supplying cooling air and the effects of varying the metal thermal conductivity from 12 to 260 Btu per hour per foot per degree Farenheit on the wheel temperatures were determined. The gas temperatures at the nozzle box used in the calculations ranged from 1600F to 2000F. The results showed that if more than a few hundred degrees of cooling of turbine blades are required other means than indirect cooling with fins on the rotor and outer blade flange would be necessary. The amount of cooling indicated for the type of finning used could produce some improvement in efficiency and a large increase in durability of the wheel. The results also showed that if a large difference is to exist between the effective temperature of the exhaust gas and that of the blade material, as must be the case with present turbine materials and the high exhaust-gas temperatures desired (2000F and above), two alternatives are suggested: (a) If metal with a thermal conductivity comparable with copper is used, then the blade temperature can be reduced ...
Date: February 11, 1947
Creator: Brown, Byron
Partner: UNT Libraries Government Documents Department

Computed Temperature Distribution and Cooling of Solid Gas-Turbine Blades

Description: Computations were made to determine the temperature distribution and cooling of solid gas-turbine blades.A range of temperatures was used from 1500 degrees to 2500 degrees F, blade-root temperatures from 100 degrees to 1000 degrees F, blade thermal conductivity from 8 to 220 BTU/(hr)(sq ft)(degrees F/ft), and net gas to metal heat transfer coefficients from 75 to 250 BTU/(hr)(sq ft)(degrees F).
Date: February 11, 1947
Creator: Reuter, J. George & Gazley, Carl, Jr.
Partner: UNT Libraries Government Documents Department

Results of Flight Test of an Automatically Stabilized Model C (Swept Back) Four-Wing Tiamat

Description: The results of the first flight test of a swept-back four-wing version of Tiamat (MX-570 model C) which was launched at the NACA Pilotless Aircraft Research Station at W4110PB Island, Va. are presented. In general, the flight behavior was close to that predicted by calculations based an stability theory and oscillating table tests of the autopilot. The flight test thus indicates that the techniques employed to predict automatic stability are valid and practical from an operational viewpoint. The limitations of the method used to predict flight behavior arise from the fact that the calculations assume no coupling among roll, pitch, and yaw, while in actual flight some such coupling does exist.
Date: June 11, 1947
Creator: Seacord, Charles L., Jr. & Teitelbaum, J. M.
Partner: UNT Libraries Government Documents Department

Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method

Description: A 1/12-scale model of a horizontal tail of a fighter airplane was tested through the transonic speeds in the high-speed flow over an airplane wing, the surface of which served as a reflection plane for the model. Measurements of lift, elevator-hinge moment, angle of attack, and elevator angle were made in the Mach number range from 0.75 to 1.04 for elevator deflections ranging from 10 degrees to minus 10 degrees, and for angles of attack of minus 1.2 degrees, 0.4 degrees, and 3.4 degrees. The equipment used to measure the hinge moments of the model proved to be unsatisfactory, and for this reason the hinge-moment data are considered to be only qualitative.
Date: April 11, 1947
Creator: Adams, Richard E. & Silsby, Norman S.
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines, 3, Analysis of Rotor and Blade Temperatures in Liquid-Cooled Gas Turbines

Description: A theoretical analysis of the radial temperature distribution through the rotor and constant cross sectional area blades near the coolant passages of liquid cooled gas turbines was made. The analysis was applied to obtain the rotor and blade temperatures of a specific turbine using a gas flow of 55 pounds per second, a coolant flow of 6.42 pounds per second, and an average coolant temperature of 200 degrees F. The effect of using kerosene, water, and ethylene glycol was determined. The effect of varying blade length and coolant passage lengths with water as the coolant was also determined. The effective gas temperature was varied from 2000 degrees to 5000 degrees F in each investigation.
Date: February 11, 1947
Creator: Brown, W. Byron & Livingood, John N. B.
Partner: UNT Libraries Government Documents Department

Knock-Limited Performance of Triptane and 28-R Fuel Blends as Affected by Changes in Compression Ratio and in Engine Operating Variables

Description: From Summary: "A knock-limited performance investigation was conducted on blends of triptane and 28-P fuel with a 12-cylinder, V-type, liquid-cooled aircraft engine of 1710-cubic-inch displacement at three compression ratios: 6.65, 7.93, and 9.68. At each compression ratio, the effect of changes in temperature of the inlet air to the auxiliary-stage supercharger and in fuel-air ratio were investigated at engine speeds of 2280 and. 3000 rpm. The results show that knock-limited engine performance, as improved by the use of triptane, allowed operation at both take-off and cruising power at a compression ratio of 9.68."
Date: March 11, 1947
Creator: Brun, Rinaldo J.; Feder, Melvin S. & Fisher, William F.
Partner: UNT Libraries Government Documents Department

Development of inboard nacelle for the XB-36 airplane

Description: From Summary: "A series of investigations of several 1/14-scale models of an inboard nacelle for the XB-36 airplane was made in the Langley two-dimensional low-turbulence tunnels. The purpose of these investigations was to develop a low-drag wing-nacelle pusher combination which incorporated an internal air-flow system. As a result of these investigations, a nacelle was developed which had external drag coefficients considerably lower than the original basic form with the external nacelle drag approximately one-half to two-thirds of those of conventional tractor designs. The largest reductions in drag resulted from sealing the gaps between the wing flaps and nacelle, reducing the thickness of the nacelle training-edge lip, and bringing the under-wing air inlet to the wing leading edge."
Date: February 11, 1947
Creator: Nuber, Robert J.
Partner: UNT Libraries Government Documents Department

Theoretical Evaluation of Methods of Cooling the Blades of Gas Turbines

Description: A study was made of heat transfer in turbine blades and the effects on blade temperature of cooling the blade root and tip, changing the dimensions of the blades, raising the cycle temperatures, insulating with ceramics, and cooling by circulation of air or water through hollow blades.
Date: February 11, 1947
Creator: Sanders, J. C. & Mendelson, Alexander
Partner: UNT Libraries Government Documents Department

Investigation of the I-40 Jet-Propulsion Engine in the Cleveland Altitude Wind Tunnel. V - Operational Characteristics, 5, Operational Characteristics

Description: An investigation has been conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of the I-40 jet-propulsion engine over a range of pressure altitudes from 10,000 to 50,000 feet and ram-pressure ratios from 1.00 to 1.76. Engine operational data were obtained with the engine in the standard configuration and with various modifications of the fuel system, the electrical system, and the combustion chambers. The effects of altitude and airspeed on operating speed range, starting, windmilling, acceleration, speed regulation, cooling, and vibration of the standard and modified engines were determined, and damage to parts was noted.
Date: July 11, 1947
Creator: Golladay, Richard L. & Gendler, Stanley L.
Partner: UNT Libraries Government Documents Department

Supersonic wave drag of sweptback tapered wings at zero lift

Description: An analysis has been made of airfoil data taken on several NACA 16-series propeller airfoils from tests of 5-inch-chord models in the Langley 24 inch high-speed tunnel and l2-inch-chord models in the Langley 8 foot high-speed tunnel, This analysis has shown that the combined effects of Reynolds number changes and variations in airfoil characteristics resulting from differences in models and tunnels are such that when 5 inch-chord and l2-inch-chord data are applied to full-scale propeller design at or near the design condition, differences of less than 1 percent in efficiency will be involved.
Date: June 11, 1947
Creator: Margolis, Kenneth
Partner: UNT Libraries Government Documents Department

Preliminary tests to determine the maximum lift of wings at supersonic speeds

Description: Report presenting the results of a test program in a supersonic tunnel to determine the maximum lift of wings operating at supersonic speeds. A variety of wing plan forms of several thickness distributions were tested at a range of Mach numbers, Reynolds numbers, and angles of attack. The lift results, drag results, and Schileren photographs are described.
Date: December 11, 1947
Creator: Gallagher, James J. & Mueller, James N.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of wing inlets for a four-engine airplane

Description: Report presenting an investigation in the propeller-research tunnel to develop wing-leading-edge inlets for locations between the inboard and outboard nacelles on each wing of a four-engine airplane. Testing was performed on the basic wing and original inlet as well as NACA-developed inlets for two versions of the airplane.
Date: March 11, 1947
Creator: Bartlett, Walter A., Jr. & Goral, Edwin B.
Partner: UNT Libraries Government Documents Department

Altitude-wind-tunnel investigation of thrust augmentation of a turbojet engine 3: performance with tail-pipe burning in standard-size tail pipe

Description: From Introduction: "Evaluation of tail-pipe burning in this engine with a larger tail-pipe combustion chamber is discussed in reference 1. Results of investigations on tail-pipe burning in this engine at static sea-level conditions are presented in reference 2. An investigation of thrust augmentation by means of injecting water at the inlet of an axial-flow compressor engine is discussed in reference 3."
Date: August 11, 1947
Creator: Fleming, William A. & Golladay, Richard L.
Partner: UNT Libraries Government Documents Department

Observations on an aileron-flutter instability encountered on a 45 degree swept-back wing in transonic and supersonic flight

Description: Report presenting a flight test of a supersonic research pilotless aircraft in which large-amplitude aileron oscillations, most likely aileron compressibility flutter, were encountered in the transonic and supersonic speed ranges. Results regarding power-on flight and coasting flight are provided.
Date: April 11, 1947
Creator: Pitkin, Marvin; Gardner, William N. & Curfman, Howard J., Jr.
Partner: UNT Libraries Government Documents Department

A comparison with flight data of vertical-tail loads in various maneuvers estimated from sideslip angles and rudder deflections

Description: Report presenting a comparison of the vertical-tail loads determined from pressure-distribution measurements in flight in various maneuvers with the corresponding vertical-tail loads. Some of the maneuvers investigated included slow rolls, steady sideslips, fishtails, and rolling pull-outs.
Date: December 11, 1947
Creator: Turner, Howard L.
Partner: UNT Libraries Government Documents Department