Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel (open access)

Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel

Report presenting testing to obtain experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. Testing occurred over a wide range of air flows and density altitudes.
Date: July 1944
Creator: Goldstein, Arthur W. & Ellerbrock, Herman H., Jr.
System: The UNT Digital Library
The Effect of Increased Cooling Surface on Performance of Aircraft-Engine Cylinders as Shown by Tests of the NACA Cylinder (open access)

The Effect of Increased Cooling Surface on Performance of Aircraft-Engine Cylinders as Shown by Tests of the NACA Cylinder

Report presenting a method of constructing fins of nearly optimum proportions to the point where a cylinder has been manufactured and tested. Data were obtained on cylinder temperature for a wide range of inlet-manifold pressures, engine speeds, and cooling-pressure differences. Results regarding cooling equations, cylinder-temperature relationships, and a comparison of three cylinder cooling performances are provided.
Date: July 1944
Creator: Schey, Oscar W.; Rollin, Vern G. & Ellerbrock, Herman H., Jr.
System: The UNT Digital Library
Wind tunnel investigation of control surface characteristics 9: some analytical considerations and experimental test results for an internally balanced flap (open access)

Wind tunnel investigation of control surface characteristics 9: some analytical considerations and experimental test results for an internally balanced flap

Report presenting an analysis of the probable aerodynamic section characteristics of a plain flap with various arrangements of internal balance. The results of the calculations previously obtained were found to be in agreement with the experiment. Some possible applications of the data to balancing tabs are also provided.
Date: July 1942
Creator: Sears, Richard I.
System: The UNT Digital Library
Wind-Tunnel Investigation of Control-Surface Characteristics: [Part] 7 - A Medium Aerodynamic Balance of Two Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0015 Airfoil (open access)

Wind-Tunnel Investigation of Control-Surface Characteristics: [Part] 7 - A Medium Aerodynamic Balance of Two Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0015 Airfoil

Report presenting force-test measurements in two-dimensional flow made in the 4- by 6-foot vertical tunnel of the characteristics of an NACA 0015 airfoil with a balanced flap with a chord 30 percent of the airfoil chord and a flap-nose overhang 35 percent of the flap chord. Results regarding lift, hinge moment of flap, pitching moment, drag, and tab characteristics are provided.
Date: July 1942
Creator: Sears, Richard I. & Hoggard, H. Page, Jr.
System: The UNT Digital Library
A Comparison of Two Flight-Test Procedures for the Determination of Aileron Control Capabilities of an Airplane (open access)

A Comparison of Two Flight-Test Procedures for the Determination of Aileron Control Capabilities of an Airplane

Report presenting a comparison of two flight-test procedures for the determination of the aileron control capabilities of an airplane. The procedures consist of performing rudder-fixed aileron rolls from straight unbanked flight and from steady turning flight. Results regarding rate of roll comparison and sideslip-angle comparison are provided.
Date: July 1945
Creator: Skoog, Richard B.
System: The UNT Digital Library
Wind-tunnel investigation of control-surface characteristics 8: a large aerodynamic balance of two nose shapes used with a 30-percent-chord flap on an NACA 0015 airfoil (open access)

Wind-tunnel investigation of control-surface characteristics 8: a large aerodynamic balance of two nose shapes used with a 30-percent-chord flap on an NACA 0015 airfoil

Report presenting force tests in two-dimensional flow in the 4- by 6-foot vertical tunnel of the characteristics of an NACA 0015 airfoil with a balanced flap having a chord of 30 percent of the airfoil chord, a flap-nose overhang 50 percent of the flap chord, and a tab having a chord 20 percent of the flap chord. Results regarding the precision and presentation of data, lift, hinge moment of flap, pitching moments, drag, tab characteristics, and balancing effectiveness of various overhangs are provided.
Date: July 1942
Creator: Sears, Richard I. & Gillis, Clarence L.
System: The UNT Digital Library
Wind-tunnel tests of four full-scale seaplane floats (open access)

Wind-tunnel tests of four full-scale seaplane floats

Report presenting wind tunnel testing of four full-scale seaplane floats to determine the aerodynamic characteristics of the floats and to evaluate several drag-reducing refinements. Four floats were investigated; two differed only in external details like flush rivets, while one was the type used on twin-float installations. The variation of lift, drag, and pitching moment with pitch angle are presented for each float.
Date: July 1943
Creator: Conway, Robert N. & Maynard, Julian D.
System: The UNT Digital Library
Wind-tunnel investigation of an NACA full-span high-lift lateral-control combination 1: section characteristics, NACA 23012 airfoil (open access)

Wind-tunnel investigation of an NACA full-span high-lift lateral-control combination 1: section characteristics, NACA 23012 airfoil

Report presenting an investigation in the 7- by 10-foot wind tunnel to determine the aerodynamic section characteristics of several arrangements of an NACA full-span high-lift lateral-control combination. The combination consists of a full-span flap of airfoil profile that retracts ahead of a narrow-chord full-span aileron. Results regarding coefficients, precision, plain airfoil, determination of optimum aileron-flap arrangement, section aerodynamic characteristics, and lateral-control characteristics are provided.
Date: July 1942
Creator: Rogallo, F. M. & Lowry, John G.
System: The UNT Digital Library
Knocking Tendency of an Air-Cooled Aircraft-Engine Cylinder With One and With Two Spark Plugs (open access)

Knocking Tendency of an Air-Cooled Aircraft-Engine Cylinder With One and With Two Spark Plugs

Report presenting tests conducted with an air-cooled aircraft-engine cylinder to determine the effect on the knocking tendency of cutting out one spark plug when the engine is operating at or near the knock point with two spark plugs firing. The results indicate that cutting out one spark plug will not lead to knock but will actually stop or decrease knock that is occurring with both spark plugs firing.
Date: July 1943
Creator: Spencer, R. C. & Jones, A. W.
System: The UNT Digital Library
The effect of cooling-air blowers on thrust power (open access)

The effect of cooling-air blowers on thrust power

Report presenting an analysis of the effect of cooling-air blowers on thrust power using an assumed airplane. Results indicated that when aviation-engine heat exchangers are used above their design altitude, blowers may be used to give additional available pressure and to increase jet thrust. Results regarding airplane speed, altitude, fin width, physical significance of the heat cycle, and thermodynamic efficiency are provided.
Date: July 1944
Creator: Palmer, Carl B. & Brevoort, Maurice J.
System: The UNT Digital Library
Design, selection, and installation of aircraft heat exchangers (open access)

Design, selection, and installation of aircraft heat exchangers

Report presenting a survey of aircraft heat exchangers in three parts: design, selection, and installation. Appendices give the physical properties of air, properties of standard atmosphere as defined by the Navy, Army, and NACA, and an impact-pressure chart.
Date: July 1943
Creator: Wood, George P. & Brevoort, Maurice J.
System: The UNT Digital Library
Relation of Preignition and Knock to Allowable Engine Temperatures (open access)

Relation of Preignition and Knock to Allowable Engine Temperatures

"The results are given of an investigation of some of the limitations that now prevent increases in the temperature level of engine cylinder heads, and a review of previous work in the field is included to supplement these results. Attention was given, in particular, to the effects of fuel knock and surface ignition on cylinder temperatures and the effects of cylinder temperatures on performance. Data were obtained from a Wright C9GC air-cooled cylinder and from a Lycoming O-1230 liquid-cooled cylinder" (p. 1).
Date: July 1943
Creator: Biermann, Arnold E. & Corrington, Lester C.
System: The UNT Digital Library
Tests of Propeller-Speed Cooling Blowers (open access)

Tests of Propeller-Speed Cooling Blowers

Report presenting testing of cooling blowers for air-cooled engine installations and an exploration of the methods used in the blower design and operating characteristics of the blowers over a range of flight speeds and altitudes. The results indicate that the blowers operate as a more efficient type of propeller cuff and in many cases provide considerably more pressure boost than using a cuff.
Date: July 1942
Creator: Silverstein, Abe
System: The UNT Digital Library
Determination of the Stability and Control Characteristics of Airplanes from Tests of Powered Models (open access)

Determination of the Stability and Control Characteristics of Airplanes from Tests of Powered Models

Report presenting a technique of testing wind tunnel powered models developed as a result of experience gained in the investigation of the static longitudinal and lateral staiblity and control characteristics of several powered models in the 7- by 10-foot wind tunnel. A discussion of the conditions to be investigated, methods of presenting and interpreting the data, and a suggested operating technique are given.
Date: July 1942
Creator: Recant, Isidore G.
System: The UNT Digital Library
Calculated effects of full-span slotted and Fowler flaps on longitudinal stability and control characteristics for a typical fighter-type airplane with various tail modifications (open access)

Calculated effects of full-span slotted and Fowler flaps on longitudinal stability and control characteristics for a typical fighter-type airplane with various tail modifications

Report presenting an analytical study of the influence of full-span slotted and Fowler flaps on the requirements for horizontal tail surfaces. The elevator deflection required to land at three-point attitude, elevator deflection required to stall the airplane at altitude, and permissible center-of-gravity range have been calculated for a fighter-type airplane.
Date: July 1942
Creator: Goranson, R. Fabian
System: The UNT Digital Library
Airspeed Fluctuations as a Measure of Atmospheric Turbulence (open access)

Airspeed Fluctuations as a Measure of Atmospheric Turbulence

"Increments in structural loads due to atmospheric turbulence can be accurately expressed in terms of flight speed and effective gust velocities (reference 4). Data from which the effective gust velocities could be computed were also obtained during the flights of the XC-35 airplane. These data have been used to determine the significance of the fluctuations in the pilot's indicated-airspeed readings in relation to structural loads to due to atmospheric turbulence" (p. 3).
Date: July 1945
Creator: Tolefson, H. B.
System: The UNT Digital Library
Airfoil-Contour Modifications Based on (Epsilon)-Curve Method of Calculating Pressure Distribution (open access)

Airfoil-Contour Modifications Based on (Epsilon)-Curve Method of Calculating Pressure Distribution

From Introduction: "Certain alternations of a qualitative nature may be performed in spite of the fact that a pressure change cannot be prescribed. It is the purpose of this paper to indicate a method by which qualitative alternation may be performed. It will be noted that the present method of contour modification will serve the intended purpose of the inverse method."
Date: July 1944
Creator: Theodorsen, Theodore
System: The UNT Digital Library
Shear-Lag Tests of a Box Beam With a Highly Cambered Cover in Tension (open access)

Shear-Lag Tests of a Box Beam With a Highly Cambered Cover in Tension

Report discusses the results of bending tests on an open box beam designed to fail on the highly cambered tension side. Results in the elastic range and ultimate-strength test are provided. The stringer stresses near the root were in fair agreement with stresses calculated by shear-lag theory and the ultimate tensile strength developed by the beam was only a little higher than the tensile yield stress of the material.
Date: July 1945
Creator: Peterson, James P.
System: The UNT Digital Library
Porpoising: A Comparison of Theory With Experiment (open access)

Porpoising: A Comparison of Theory With Experiment

Report presenting a direct comparison between the observed and the calculated longitudinal dynamic stability of a particular dynamic model of a flying boat moving on the water. Good agreement was obtained between experiment and theory for trim angles in the vicinity of lower limit, at one speed a little above the hump.
Date: July 1943
Creator: Davidson, Kenneth S. M.; Locke, F. W. S., Jr. & Suarez, Anthony
System: The UNT Digital Library
An Experimental Investigation of the Effect of Propellers Used as Aerodynamic Brakes on Stability and Control (open access)

An Experimental Investigation of the Effect of Propellers Used as Aerodynamic Brakes on Stability and Control

"Tests were made of a model representative of a single-engine tractor-type airplane for the purpose of determining the stability and control effects of a propeller used as an aerodynamic brake. The tests were made with single-and dual-rotation propellers to show the effect of type of propeller rotation, and with positive thrust to provide basic data with which to compare the effects of negative thrust. Four configurations of the model were used to give the effects of tilting the propeller thrust axis down 5 deg., raising the horizontal tail, and combining both tilt and raised tail" (p. 1).
Date: July 1945
Creator: Stevens, Victor I.; McCullough, George B. & Hanson, Frederick H.
System: The UNT Digital Library
Wind-tunnel investigation of a plain aileron and a balanced aileron on a tapered wing with full-span duplex flaps (open access)

Wind-tunnel investigation of a plain aileron and a balanced aileron on a tapered wing with full-span duplex flaps

Report presenting an investigation of a plain aileron and a balanced aileron on a tapered wing with full-span duplex flaps, which consisted of an inboard NACA slotted flap and an outboard balanced split flap. Increments of maximum lift coefficient of 0.82 and 1.04 were obtained from the inboard flap alone and from the duplex-flap combination.
Date: July 1942
Creator: Rogallo, F. M. & Lowry, John G.
System: The UNT Digital Library
Wind-tunnel investigation of a tapered wing with a plug-type spoiler-slot aileron and full-span slotted flaps (open access)

Wind-tunnel investigation of a tapered wing with a plug-type spoiler-slot aileron and full-span slotted flaps

Report presenting an investigation in the 7- by 10-foot wind tunnel of several arrangements of a plug-type spoiler-slot aileron on a tapered wing model of a typical fighter airplane with a full-span slotted flap. When the aileron is deflected, the plug projects from the upper surface of the wing as a spoiler and makes a slot appear behind the spoiler.
Date: July 1942
Creator: Lowry, John G. & Liddell, Robert B.
System: The UNT Digital Library
Working Charts for the Computation of Propeller Thrust Throughout the Take-Off Range (open access)

Working Charts for the Computation of Propeller Thrust Throughout the Take-Off Range

Report presenting data from tests conducted on full-scale propellers with 3155 blade design, which have been used to construct a set of propeller thrust charts for use in the calculation of take-off performance. By using the charts, the thrust of modern single- and dual-rotating propellers may be easily and rapidly calculated through the entire take-off range.
Date: July 1943
Creator: Desmond, Gerald L. & Freitag, Robert F.
System: The UNT Digital Library
Aluminum-Zinc-Magnesium-Copper Casting Alloys (open access)

Aluminum-Zinc-Magnesium-Copper Casting Alloys

From Introduction: "This paper contains data on the mechanical properties of sand-cast test bars having a considerable range in zinc, magnesium, and copper content and more detailed data on the properties and foundry characteristics of an aluminum-zinc-magnesium-copper alloy having a preferred composition for high strength and ductility."
Date: July 1941
Creator: Kempf, L. W.
System: The UNT Digital Library