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  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Memorandum Report
Single-cylinder oil-control tests of porous chrome plated cylinder barrels for radial air-cooled engines
No Description digital.library.unt.edu/ark:/67531/metadc279560/
Wind-tunnel investigation of the effects of spoilers on the characteristics of a low-drag airfoil equipped with a 0.25-chord slotted flap
No Description digital.library.unt.edu/ark:/67531/metadc279657/
An investigation of a thermal ice-prevention system for a C-46 cargo airplane V : effect of thermal system on airplane cruise performance
No Description digital.library.unt.edu/ark:/67531/metadc279663/
Effect of the performance of a turbosupercharged engine of an exhaust-gas-to-air heat exchanger for thermal ice prevention
No Description digital.library.unt.edu/ark:/67531/metadc279594/
Tests of a thermal ice-prevention system for a wing leading-edge landing-light installation
No Description digital.library.unt.edu/ark:/67531/metadc279556/
Effect of Maximum Cruise-Power Operation at Ultra-Lean Mixture and Increased Spark Advance on the Mechanical Condition of Cylinder Components
A continuous 50-hour test was conducted to determine the effect of maximum cruise-power operation at ultra-lean fuel-air mixture and increased spark advance on the mechanical conditions of cylinder components. The test was conducted on a nine-cylinder air-cooled radial engine at the following conditions:brake horsepower, 750; engine speed, 1900 rpm; brake mean effective pressure, 172 pounds per square inch; fuel-air ratio, 0.052; spark advance, 30 deg B.T.C.; and maximum rear-spark-plug-bushing temperature, 400 F. In addition to the data on corrosion and wear, data are presented and briefly discussed on the effect of engine operation at the conditions of this test on economy, knock, preignition, and mixture distribution. Cylinder, piston, and piston-ring wear was small and all cylinder component were in good condition at the conclusion of the 50-hour test except that all exhaust-valve guides were bellmouthed beyond the Army's specified limit and one exhaust-valve face was lightly burned. It is improbable that the light burning in one spot of the valve face would have progressed further because the burn was filled with a hard deposit so that the valve face formed an unbroken seal and the mating seat showed no evidence of burning. The bellmouthing of the exhaust-valve guides is believed to have been a result of the heavy carbon and lead-oxide deposits, which were present on the head end of the guided length of the exhaust-valve stem. Engine operational the conditions of this test was shown to result In a fuel saving of 16.8 percent on a cooled-power basis as compared with operation at the conditions recommended for this engine by the Army Air Forces for the same power. digital.library.unt.edu/ark:/67531/metadc61884/
Measurements of the flying qualities of a Bell P-39D-1 airplane (AAF NO. 41-28378)
No Description digital.library.unt.edu/ark:/67531/metadc61077/
Attainment of a straight-line trajectory for a preset guided missile with special reference to effect of wind or target motion
No Description digital.library.unt.edu/ark:/67531/metadc62433/
Rubber conductors for aircraft ignition cables
No Description digital.library.unt.edu/ark:/67531/metadc62514/
Two-dimensional wind-tunnel investigation of 0.20-airfoil-chord plain ailerons of different contour on an NACA 65(sub 1)-210 airfoil section
No Description digital.library.unt.edu/ark:/67531/metadc61394/
Cooling of Gas Turbines, 2, Effectiveness of Rim Cooling of Blades
An analysis of rim cooling, which cools the blade by condition alone, was conducted. Gas temperatures ranged from 1300 degrees to 1900 degrees F and rim temperatures from 0 degrees to 1000 degrees F below gas temperatures. Results show that gas temperature increases up to 200 degrees F are permissible provided that the blades are cooled by 400 degrees to 500 degrees F below the gas temperature. Relatively small amounts of blade cooling, at constant gas temperature, give large increases in blade life. Dependence of rim cooling on heat-transfer coefficient, blade dimensions, and thermal conductivity is determined by a single parameter. digital.library.unt.edu/ark:/67531/metadc65597/
An Experimental Investigation of NACA Submerged-Duct Entrances
The results of an investigation of submerged-duct entrances are presented. It is shown that this type of entrance possesses the following characteristics: 1) very high-critical-compressibility speeds throughout the range of high-speed inlet velocity ratios; 2) very low pressure losses for the air entering the duct at all inlet-velocity ratios; and, 3) low external drag. These characteristics are obtained by the proper shaping of the contour of the upstream approach to the submerged inlets and by proper alignment of the duct lip. Design data are presented and the application of these data to a specific high-speed fighter-airplane design is discussed. digital.library.unt.edu/ark:/67531/metadc65007/
Wind-Tunnel Tests of a Portion of a PV-2 Helicopter Rotor Blade
A portion of a PV-2 helicopter rotor blade has been tested in the 6- by 6-foot test section of the Langley stability tunnel to determine if the aerodynamic characteristics were seriously affected by cross flow or fabric distortion. The outer portion of the blade was tested as a reflection plane model pivoted about the tunnel wall to obtain various angles of cross flow over the blade. Because the tunnel wall acts as a plane of sy~try, the measured aerodynamic characteristics correspond to those of an airfoil having various angles of sweepforward and sweepback. Tests were made with the vents on the lower surface open and also with the vents sealed and the internal pressure held at -20 inches of water producing an internal pressure coefficient of -1.059. The change in contour resulting from the range of internal pressures used had very little effect on the aerodynamic characteristics of the blade. The test methods were considered to simulate inadequately the flow conditions over the rotor blade because the effects of cross flow were limited to conditions corresponding to sweep of the blade. The results indicated that this type of cross flow had only minor effects on the aerodynamic characteristics of the blade. It is believed, therefore, that future tests to determine the effects on the aerodynamic characteristics of cross flow should utilize complete rotors. digital.library.unt.edu/ark:/67531/metadc65602/
Tests of a 1/7-Scale Semispan Model of the XB-35 Airplane in the Langley 19-Foot Pressure Tunnel
A 1/7 scale semispan model of the XB-35 airplane was tested in the Langley 10 foot pressure tunnel, primarily for the purpose of investigating the effectiveness of a leading-edge slot for alleviation of stick-fixed longitudinal instability at high angles of attack caused by early tip stalling and a device for relief of stick-free instability caused by elevon up-floating tendencies at high angles of attack. Results indicated that the slot was not adequate to provide the desired improvement in stick-fixed stability. The tab-flipper device provided improvement in stick-free stability abd two of the linkage combinations tested gave satisfactory variations of control force with airspeed for all conditions except that in which the wing-tip "pitch-control" flap was fully deflected. However, the improvement in control force characteristics was accompanied by a detrimental effect on stick-fixed stability because of the pitching moments produced by the elevon tab deflection. digital.library.unt.edu/ark:/67531/metadc64054/
Wind-Tunnel Tests of a 1/6-Scale Model of Republic XF-12 Vertical Tail with Stub Fuselage and Stub Horizontal Tail
A 1/6-scale model of the Republic XF-12 vertical tail with stub fuselage and stub horizontal tail was tested in the Langley stability tunnel to determine the aerodynamic characteristics of the model, The investigation included a study of the effects of boundarylayer thickness, rudder area, and cover-plate alinement on the aerodynamic characteristics. Tuft studies were made in the vicinity of the junction of the vertical and stub horizontal tails. The results of the investigation indicated that the flow in the vicinity of the junction of the vertical and stub horizontal tails was only slightly improved by the addition of a fillet. An increase in boundary-layer thickness produced a slight decrease in rudder effectiveness. The increase in lift of the combined rudders over that of the upper rudder alone was not proportional at low deflections and was approximately proportional at high deflections to the increase in rudder area. When the balance-chamber cover plates were bowed out, the change in rudder hinge moment with rudder angle was less negative. The variation of the lift coefficient with angle of attack and the variation, at small values of angle of attack, of rudder hinge-noment coefficient with angle of attack was approximately the same for all model configurations tested. The upper rudder used in conjunction with a tab was found to satisfy the Army specifications regarding asymmetric power on a multiengine airplane. digital.library.unt.edu/ark:/67531/metadc64933/
Wind-Tunnel Tests of a 1/5-Scale Semispan Model of the Republic XF-12 Horizontal Tail Surface
Wind-tunnel tests of a 1/5-scale semispan model of the Republic XF-12 horizontal tail surface equipped with an internally balanced elevator were conducted in the 6- by 6-foot test section of the Langley stability tunnel. The tests included measurements of the aerodynamic characteristics of the horizontal tail with and without a beveled trailing edge and also included measurements of the tab characteristics. The variation of the aerodynamic characteristics with boundary-layer conditions and leakage in the internal-balance chambers, measurements of the boundary-layer displacement thickness near the elevator hinge axis, and pressure distributions at the mean geometric chord were also obtained. The results showed that the hinge-moment characteristics of the elevator were critical to boundary-layer conditions and internal-balance leakage. Increasing the boundary-layer displacement thickness by use of roughness strips reduced the rate of change of elevator hinge moments with tab deflection by about 20 percent. The present horizontal tail appears to be unsatisfactory for longitudinal stability with power on, however, an increase in horizontal-tail lift effectiveness should correct this difficulty. The maneuvering stick force per unit acceleration will be extremely critical to minor variations of the elevator hinge moments if the elevator is linked directly to the stick. digital.library.unt.edu/ark:/67531/metadc64935/
Aerodynamic Characteristics of Four Republic Airfoil Sections from Tests in Langley Two-Dimensional Low-Turbulence Tunnels
Four airfoils sections, designed by the Republic Aviation Corporation for the root and tip sections of the XF-12 airplane, were tested in the Langley two-dimensional low-turbulence tunnels to obtain their aerodynamic characteristics. Lift characteristics were obtained at Reynolds numbers of 3,000,000, 6,000,000, 9,000,000, and 14,000,000, whereas drag characteristics were obtained at Reynolds numbers of 3,000,000, 6,000,000, and 9,000,000. Pressure distributions were obtained for one of the root sections for several angles of attack at a Reynolds number of 2,600,000. Comparison of the root section that appeared best from the tests with the corresponding NACA 65-series section shows the Republic section has a higher maximum lift and higher calculated critical speeds, but a higher minimum drag. In addition, with standard roughness applied to the leading edge, the maximum lift of the Republic airfoil is lower than that of the NACA airfoil. Comparison of the Republic tip section with the corresponding NACA 65-series section shows the Republic airfoil has a lower maximum lift and a higher minimum drag than the NACA airfoil. The calculated critical speeds of the Republic section are slightly higher than those of the NACA section. digital.library.unt.edu/ark:/67531/metadc64938/
Wind-Tunnel Tests of a 1/6-Scale Model of Republic XF-12 Vertical Tail Incorporating a De-Icing Air Duct
A 1/6-scale model of the Republic XF-12 vertical tail with stub fuselage, stub horizontal tail, and a de-icing air duct was tested in the Langley stability tunnel. The investigation consisted of a study of the effects of the duct, with and without air flow, on the aerodynamic characteristics of the model. The model tested was a revision of a model previously tested in the Langley stability tunnel. The revised model differed from the original model in that it incorporated a de-icing air duct, included a dorsal fin, and had a larger stub fuselage. A comparison of data obtained form tests of the original and revised models was made. The results of the investigation indicated that the air duct had very little effect on the aerodynamic characteristics of the model. A small change occurred in the variation of rudder hinge-moment coefficient with angle of attack but it is believed that this change can be corrected by a properly applied spring tab. digital.library.unt.edu/ark:/67531/metadc64934/
Vibration-response tests of a 1/5-scale model of the Grumman F6F airplane in the Langley 16-foot high-speed tunnel
No Description digital.library.unt.edu/ark:/67531/metadc60875/
Some notes on the effects of jet-exit design on static longitudinal stability
No Description digital.library.unt.edu/ark:/67531/metadc60945/
The effect of afterbody length of the hydrodynamic stabilit y of a dynamic model of a flying boat : Langley tank model 134
No Description digital.library.unt.edu/ark:/67531/metadc62685/
Flight investigation of factors affecting the carburetor ram and nacelle drag of an A-26B airplane
No Description digital.library.unt.edu/ark:/67531/metadc62684/
Tests of the jet-motor air-intake duct system on a 1/4-scale stub-wing model of a pursuit-type airplane
No Description digital.library.unt.edu/ark:/67531/metadc62023/
Bending and shear stresses developed by the instantaneous arrest of the root of a cantilever beam with a mass at its tip
No Description digital.library.unt.edu/ark:/67531/metadc62215/
An evaluation of the knock-limited performance of triptane
No Description digital.library.unt.edu/ark:/67531/metadc62312/
The effect of ethylene dibromide on the knock-limited performance of leaded and nonleaded S reference fuel
No Description digital.library.unt.edu/ark:/67531/metadc62310/
Characteristics of several single- and dual-rotating propellers in negative thrust
No Description digital.library.unt.edu/ark:/67531/metadc62187/
Aerodynamic characteristics of several modifications of a 0.45-scale model of the vertical tail of the Curtiss XP-62 airplane
No Description digital.library.unt.edu/ark:/67531/metadc62683/
Calibrations of service pitot tubes in the Langley 24-inch high-speed tunnel
No Description digital.library.unt.edu/ark:/67531/metadc62408/
Wind-tunnel tests of the 0.15-scale powered model of the Fleetwing XBTK-1 airplane : lateral stability and control
No Description digital.library.unt.edu/ark:/67531/metadc62649/
Analysis of V-G Records from the SNB-1 Airplane
Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours. digital.library.unt.edu/ark:/67531/metadc62643/
An analysis of the indications of the University of Chicago airborne turbulence indicator in gusty air
No Description digital.library.unt.edu/ark:/67531/metadc62668/
Knock-limited performance of six aromatic amines blended with a base fuel in a full-scale aircraft-engine cylinder
No Description digital.library.unt.edu/ark:/67531/metadc62290/
Comparison of the knock-limited performance of triptane with 23 other purified hydrocarbons
No Description digital.library.unt.edu/ark:/67531/metadc62298/
The effect of six aromatic amines on the preignition-limited performance of 28-R aviation fuel in a CFR engine
No Description digital.library.unt.edu/ark:/67531/metadc62299/
Estimation of F-3 and F-4 knock-limited performance ratings for ternary and quaternary blends containing triptane or other high-antiknock aviation-fuel blending agents
No Description digital.library.unt.edu/ark:/67531/metadc62293/
Aerodynamics of the carburetor air scoop and the engine cowling of a single-engine torpedo-bomber-type airplane
No Description digital.library.unt.edu/ark:/67531/metadc62050/
Knock-limited performance of blends of AN-F-28 fuel containing 2 percent aromatic amines IV
No Description digital.library.unt.edu/ark:/67531/metadc62352/
Knock-limited performance of blends of AN-F-28 fuel containing 2 percent aromatic amines V
No Description digital.library.unt.edu/ark:/67531/metadc62354/
Wind-Tunnel Tests of the 0.15-Scale Powered Model of the Fleetwings XBTK-1 Airplane : Longitudinal Stability and Control
An investigation was made of the static longitudinal stability, and control and stall characteristics of XBTK-1 dive bomber. Results indicate that the longitudinal stability will probably be satisfactory for all contemplated flight conditions at the rear-most CG location with elevator both fixed and free. Power effects were small. Sufficient elevator control will be available to trim in any flight condition above the ground. Increasing the slotted flap deflection above 30 degrees only slightly increased the max. lift coefficient. digital.library.unt.edu/ark:/67531/metadc62647/
The Effect of Compression Ratio on Knock Limits of High-Performance Fuels in a CFR Engine II : Blends of 2,2,3-Trimethylpentane with 28-R
The knock-limited performance of blends of 0,50; and 100 percent by volume of 2,2,3-trimethylpentane in 28-R fuel determined with a modified F-4 engine at three sets of conditions varying from severe to mild at each of three compression ratios (6.0, 8.0, and 10.0). A comparison of the knock-limited performance of 2,2,3-trimethylpentane with that of triptane (2,2,3-trimethylbutane) is included. The knock-Limited performance of 2,2,3-trimethylpontane was usually more sensitive to either compression ratio or inlet-air temperature than 28-R fuel, but the ratio of the knock-limited indicated mean effective pressure of a given blend containing 2,2,3-trimethypentane and 28-R to the indicated mean effective pressure of 28-R alone was not greatly affected by compression ratio if the engine operating conditions were mild. Although 2,2,3-trimethylpentane in general had a lower knock-limited performance than triptane, the characteristics of the two fuels were somewhat similar. digital.library.unt.edu/ark:/67531/metadc62525/
Flight and test-stand investigation of high-performance fuels in double-row radial air-cooled engines I : determination of cooling characteristics of flight engine
No Description digital.library.unt.edu/ark:/67531/metadc62522/
An investigation of cowl inlets for the B-29 power-plant installation
No Description digital.library.unt.edu/ark:/67531/metadc62526/
Flight and test-stand investigation of high-performance fuels in double-row radial air-cooled engines II : flight knock data and comparison of fuel knock limits with engine cooling limits in flight
No Description digital.library.unt.edu/ark:/67531/metadc62523/
Reduction of fuel-vapor loss by omitting some of the fuel constituents normally lost during flight
No Description digital.library.unt.edu/ark:/67531/metadc62285/
Flight variables affecting fuel-vapor loss from a fuel tank
No Description digital.library.unt.edu/ark:/67531/metadc62282/
Analysis and correlation of data obtained by six laboratories on fuel-vapor loss from fuel tanks during simulated flight
No Description digital.library.unt.edu/ark:/67531/metadc62280/
Knock-limited blending characteristics of benzene, toluene, mixed xylenes, and cumene in an air-cooled cylinder
No Description digital.library.unt.edu/ark:/67531/metadc62289/
The low-temperature solubility of 24 aromatic amines in aviation gasoline
No Description digital.library.unt.edu/ark:/67531/metadc62286/
Ditching tests with a 1/16-size dynamic model of the Army B-24 airplane in Langley tank number 2 and on an outdoor catapult
No Description digital.library.unt.edu/ark:/67531/metadc62625/
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