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Ultraviolet spectrochemical analysis for aromatics in aircraft fuels (open access)

Ultraviolet spectrochemical analysis for aromatics in aircraft fuels

Report presenting tests to verify and extend ultraviolet spectroscopic techniques for applications to the analysis of aviation fuels for their aromatic constituents. Results regarding photographic absorption spectra, spectrophotometric absorption spectra, and spectrophotometric analyses are provided.
Date: March 1945
Creator: Cleaves, Alden P.
System: The UNT Digital Library
On the Flow of a Compressible Fluid by the Hodography Method 1: Unification and Extension of Present-Day Results (open access)

On the Flow of a Compressible Fluid by the Hodography Method 1: Unification and Extension of Present-Day Results

Report presenting elementary basic solutions of the equations of motion of a compressible fluid in the hodograph variables are developed and used to provide a basis for comparison in the form of velocity correction formulas, of corresponding compressible and incompressible flows.
Date: March 1944
Creator: Garrick, I. E. & Kaplan, Carl
System: The UNT Digital Library
An Investigation of Aircraft Heaters 9: Measured and Predicted Performance of Two Exhaust Gas-Air Heat Exchangers and an Apparatus for Evaluating Exhaust Gas-Air Heat Exchangers (open access)

An Investigation of Aircraft Heaters 9: Measured and Predicted Performance of Two Exhaust Gas-Air Heat Exchangers and an Apparatus for Evaluating Exhaust Gas-Air Heat Exchangers

Report presenting laboratory testing to determine the thermal output and pressure drop characteristics of the Airesearch and Solar fluted-type exhaust gas-air heat exchangers. The apparatus used in these tests consisted of a natural gas furnace of 3,000,000 Btu per hour thermal capacity, a centrifugal blower, and a system of ducting and various measuring devices. Results regarding the method of analysis, the Airesearch heat exchanger tests, the solar heat exchanger tests, and a comparison of the two heat exchangers are provided.
Date: March 1943
Creator: Boelter, L. M. K.; Miller, M. A.; Sharp, W. H.; Morrin, E. H.; Iversen, H. W. & Mason, W. E.
System: The UNT Digital Library
The effect of altitude on cooling (open access)

The effect of altitude on cooling

Report presenting variables that control the cooling of liquid-cooled and air-cooled engines and then to show by illustrations how either engine may be cooled at any desired altitude. Cooling was found to not be the limiting factor in the design of high-altitude airplanes and was also not found to be a valid reason for selecting either liquid- or air-cooled engines for high-altitude operation.
Date: March 1943
Creator: Brevoort, Maurice J.; Joyner, Upshur T. & Wood, George P.
System: The UNT Digital Library
A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction (open access)

A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction

Report presenting charts showing the variation in dynamic stability with the rudder hinge-moment characteristics. A stabilizing rudder floating tendency combined with a high degree of aerodynamic balance is shown to lead to oscillations of increasing amplitude.
Date: March 1943
Creator: Greenberg, Harry & Sternfield, Leonard
System: The UNT Digital Library
Some Effects of Propeller Operation on the Distribution of the Load on the Vertical Tail Surface of a Typical Pursuit Airplane (open access)

Some Effects of Propeller Operation on the Distribution of the Load on the Vertical Tail Surface of a Typical Pursuit Airplane

Report discusses the results of testing on the pressure distribution at several longitudinal sections of the vertical tail surface of the Curtiss P-40K airplane at various angles of attack and angles of yaw and with the propeller removed and propeller operating. Results regarding the chordwise pressure distributions, effects of propeller operation on the spanwise distribution of normal-force coefficient, total normal-force coefficients, and effect of propeller operation on the variation of vertical-tail normal-force coefficients are presented.
Date: March 1944
Creator: Sweberg, Harold H. & Dingeldein, Richard C.
System: The UNT Digital Library
Preliminary flight research on an all-movable horizontal tail as a longitudinal control for flight at high Mach numbers (open access)

Preliminary flight research on an all-movable horizontal tail as a longitudinal control for flight at high Mach numbers

Report presenting flight tests of an all-movable horizontal tail installed on a Curtiss XP-42 airplane due to its possible advantages as a longitudinal control at high Mach numbers. The elevator control was found to be unsatisfactory with the control arrangements tested.
Date: March 1945
Creator: Kleckner, Harold F.
System: The UNT Digital Library
Wind-tunnel investigation of control-surface characteristics 5: the use of a beveled trailing edge to reduce the hinge moment of a control surface (open access)

Wind-tunnel investigation of control-surface characteristics 5: the use of a beveled trailing edge to reduce the hinge moment of a control surface

Report presenting wind tunnel testing to investigate the possibility of reducing the hinge moments of a control surface by beveling the trailing edge. Tests were made with a 9-percent-thick airfoil with a 30-percent-chord plain flap. Results regarding the variations of lift and hinge moment, effect of shapes, and pitching moments are provided.
Date: March 1942
Creator: Jones, Robert T. & Ames, Milton B., Jr.
System: The UNT Digital Library
Preliminary Report on the Characteristics of the N.A.C.A. 4400R Series Airfoils (open access)

Preliminary Report on the Characteristics of the N.A.C.A. 4400R Series Airfoils

Report presenting tests made in the variable-density wind tunnel of airfoils of the NACA 4400 series modified by reflex at the trailing edge designed to reduce the pitching moment to the value of -0.03. The modified airfoils are designated the NACA 4400R series.
Date: March 1939
Creator: Sherman, Albert
System: The UNT Digital Library
Flight Tests of a Rudder With a Spring Tab on an F6F-3 Airplane (BuAer No.04776) (open access)

Flight Tests of a Rudder With a Spring Tab on an F6F-3 Airplane (BuAer No.04776)

Report discussing testing on an F6F-3 with a spring-tab rudder to determine the directional stability and control characteristics. Using the spring-tab rudder was found to result in lower trim-force change with speed and lower pedal forces in sideslips than the original rudder. Pilots were found to prefer the maneuverability of this configuration.
Date: March 1945
Creator: Williams, Walter C.
System: The UNT Digital Library
Characteristics of plain and balanced elevators on a typical pursuit fuselage at attitudes simulating normal-flight and spin conditions (open access)

Characteristics of plain and balanced elevators on a typical pursuit fuselage at attitudes simulating normal-flight and spin conditions

Report presenting lift and elevator hinge-moment characteristics of a horizontal tail with various plain and balanced elevators and mounted on a typical pursuit fuselage as measured in the 7- by 10-foot wind tunnel at attitudes simulating normal-flight and spin conditions. The lift effectiveness of the elevator was practically independent of the size of the aerodynamic balance. Results regarding the fuselage alone and fuselage interference, lift characteristics of fuselage-tail combinations, lift effectiveness of the tab, elevator hinge moments, parameters, effect of yaw on elevator hinge moments, effect of tab on elevator hinge moments, drag, and comparison with two-dimensional data are provided.
Date: March 1942
Creator: Sears, Richard I. & Hoggard, H. Page, Jr.
System: The UNT Digital Library
An investigation of aircraft heaters 14: an air and heat flow analysis of a ram-operated heater and duct system (open access)

An investigation of aircraft heaters 14: an air and heat flow analysis of a ram-operated heater and duct system

Report presenting a method of graphical analysis that allows for the prediction of the thermal and aerodynamic performance of a ram-operated heater and duct system, for cabin heating or wing de-icing, at any altitude and airplane speed. Performance can be predicted from the isothermal total pressure drop across the components of the duct system at several ventilating air rates and the thermal output of the heater at various air and exhaust gas rates.
Date: March 1944
Creator: Boelter, L. M. K.; Morrin, E. H.; Martinelli, R. C. & Poppendiek, H. F.
System: The UNT Digital Library
The Aerodynamic Tests of Three Edo Floats for the SB2U-3, 0S2U-2, and XSB2C-2 Seaplanes - NACA Models 106-K, 107-K, and 125-AH (open access)

The Aerodynamic Tests of Three Edo Floats for the SB2U-3, 0S2U-2, and XSB2C-2 Seaplanes - NACA Models 106-K, 107-K, and 125-AH

Report presenting aerodynamic testing of scale models of the Edo seaplane floats for the SB2U-3, OS2U-2, and XSB2C-2 seaplanes. Various coefficients, pitching moment, yawing moment, and drag coefficients are provided.
Date: March 1942
Creator: Liddell, Robert B.
System: The UNT Digital Library
An investigation of aircraft heaters 10: measured and predicted performance of a fluted-type exhaust gas and air heat exchanger (open access)

An investigation of aircraft heaters 10: measured and predicted performance of a fluted-type exhaust gas and air heat exchanger

Report presenting performance data on a small exhaust gas and air heat exchanger. The heat transfer rates were measured using about 8000 pounds per hour of exhaust gas and 4300 pounds per hour of ventilating air. The thermal performance of heater no. 2 can be estimated to 3 to 17 percent by use of the method described in the report.
Date: March 1943
Creator: Boelter, L. M. K.; Dennison, H. G.; Guibert, A. G. & Morrin, E. H.
System: The UNT Digital Library
An Investigation of Aircraft Heaters 8: A Simplified Method for the Calculation of the Unit Thermal Conductance Over Wings (open access)

An Investigation of Aircraft Heaters 8: A Simplified Method for the Calculation of the Unit Thermal Conductance Over Wings

Report presenting a simplified approximate method of calculating the unit thermal conductance along an airfoil as a function of distance from the leading edge, by use of heat transfer data for smooth cylinders and smooth flat plates. Several examples are used in order to show the effectiveness of the method.
Date: March 1943
Creator: Martinelli, R. C.; Guibert, A. G.; Morrin, E. H. & Boelter, L. M. K.
System: The UNT Digital Library
Wind-Tunnel Investigation of Control-Surface Characteristics 21: Medium and Large Aerodynamic Balances of Two Nose Shapes and a Plain Overhang Used With a 0.40-Airfoil-Chord Flap on an NACA 0009 Airfoil (open access)

Wind-Tunnel Investigation of Control-Surface Characteristics 21: Medium and Large Aerodynamic Balances of Two Nose Shapes and a Plain Overhang Used With a 0.40-Airfoil-Chord Flap on an NACA 0009 Airfoil

Report discusses the results of an investigation of an NACA 0009 airfoil with a 40-percent-chord flap with medium and large aerodynamic balances of elliptical and blunt nose shapes and a plain overhang. The results are presented as aerodynamic section characteristics for several flap deflections with the gap at the flap nose sealed and unsealed.
Date: March 1945
Creator: Riebe, John M. & Church, Oleta
System: The UNT Digital Library
Wind-Tunnel Investigation of Shielded Horn Balances and Tabs on a 0.7-Scale Model of XF6F Vertical Tail Surface (open access)

Wind-Tunnel Investigation of Shielded Horn Balances and Tabs on a 0.7-Scale Model of XF6F Vertical Tail Surface

Results of subject tests indicate the difficulty of obtaining closely balanced rudder surfaces for most tail assemblies with shielded horns and maintaining a near zero rate-of-change of hinge-moment coefficient without an additional balancing device. A comparison is made between shielded and unshielded horn test results. Pressure distribution and tuft tests of flow over different shaped horns showed higher critical speed for medium-taper nosed horn. The trim tab nose shape had little effect on tab test results.
Date: March 1944
Creator: Lowry, John G.; Maloney, James A. & Garner, I. Elizabeth
System: The UNT Digital Library
Wind-Tunnel Investigation of Trimming Tabs on a Thickened and Beveled Aileron on a Tapered Low-Drag Wing (open access)

Wind-Tunnel Investigation of Trimming Tabs on a Thickened and Beveled Aileron on a Tapered Low-Drag Wing

Report presenting an investigation in the 7- by 10-foot tunnel of three inset tabs and of one attached tab on the beveled aileron of a low-drag wing. The results indicated that, of the arrangements tested, an inset tab with a chord 50 percent of the aileron chord provided the most satisfactory trimming characteristics on a beveled aileron.
Date: March 1943
Creator: Rogallo, F. M. & Crandall, Stewart M.
System: The UNT Digital Library
On the Shear Strength of Skin-Stiffener Panels With Inspection Cut-Outs (open access)

On the Shear Strength of Skin-Stiffener Panels With Inspection Cut-Outs

"Strength tests and strain measurements were made of 19 long shear panels with rectangular inspection cut-outs; that is, cut-outs obtained by removing the sheet between two adjacent stringers without cutting any stringer. The test results indicated that the stress concentration existing at low stresses tends to disappear at very high stresses and that the assumption of uniform stress distribution leads to a satisfactory correlation of the test results. Stiffening of the sheet bay containing the cut-out was found to have practically no effect on the panel strength" (p. 1).
Date: March 1945
Creator: Kuhn, Paul & Diskin, Simon H.
System: The UNT Digital Library
Application of a numerical procedure to stress analysis of stringer-reinforced panels (open access)

Application of a numerical procedure to stress analysis of stringer-reinforced panels

From Introduction: "In the present paper a numerical procedure for the stress analysis of flat-sheet and stringer combinations of arbitrary construction and loading is presented and applied to axially loaded panels and to the reinforced covers of box beams."
Date: March 1945
Creator: Kempner, Joseph
System: The UNT Digital Library
Estimation of stick-fixed neutral points of airplanes (open access)

Estimation of stick-fixed neutral points of airplanes

Report presenting a method for calculating the stick-fixed neutral point of an airplane with the propeller windmilling, the flaps neutral, and landing gear retracted. The methods used in this report should be useful in estimating the stick-fixed neutral points of new designs for all flight conditions.
Date: March 1945
Creator: White, Maurice D.
System: The UNT Digital Library
A Correlation of the Dimensions, Proportions, and Loadings of Existing Seaplane Floats and Flying Boat Hulls (open access)

A Correlation of the Dimensions, Proportions, and Loadings of Existing Seaplane Floats and Flying Boat Hulls

Report presenting a study to determine what loadings and proportions have been chosen by designers of seaplanes and flying boats and what, if any, interrelations exist between the loadings and proportions. The characteristics considered include the beam, getaway speed, forebody length, afterbody length, hull length, center of gravity, and brake horsepower necessary.
Date: March 1943
Creator: Locke, Fred W. S., Jr.
System: The UNT Digital Library
Tests of Hydraulically Expanded Rivets (open access)

Tests of Hydraulically Expanded Rivets

Report discusses the results of an investigation into the tightness, shear strength, tensile strength, and life under pulsating loads of hollow, hydraulically expanded rivets made of 17S-T aluminum alloy. The countersunk-head rivets with inserts had a much higher maximum load in shear than the modified-roundhead rivets, which did not have inserts.
Date: March 1944
Creator: Mandel, Merven W.; Crate, Harold & Schuette, Evan H.
System: The UNT Digital Library
The Effect of Continuous Knock on the Endurance of an Aircraft Engine Cylinder (open access)

The Effect of Continuous Knock on the Endurance of an Aircraft Engine Cylinder

Report presenting an investigation to determine any injurious effects of knock on engine parts. Endurance tests were run on a single-cylinder engine to compare the conditions of cylinders operated with and without knock. Results regarding the history of the tests, conditions of pistons and cylinders, absence of surface ignition, and effect of knock on cylinder temperatures are provided.
Date: March 1944
Creator: Sanders, J. C.; Hilgendorf, J. A. & Peters, M. D.
System: The UNT Digital Library