UNT Libraries Government Documents Department - 533 Matching Results
Search Results
- High-Altitude Cooling 3: Radiators
- Report details the methods of determining the heat-transfer rate, pressure drop, and drag power of high-altitude radiators. Performance charts are provided for a wide range of design variables.
- Secondary Stresses in Open Box Beams Subjected to Torsion
- In open box beams subjected to torsion, secondary stresses arise owing to lateral bending of the spar caps. The present paper outlines a simple method for estimating the magnitude of these stresses and gives the results of tests of an open box beam in the neighborhood of a discontinuity where the cover changed from the top to the bottom of the box.
- Stresses Near the Juncture of a Closed and an Open Torsion Box as Influenced by Bulkhead Flexibility
- Report discussing an open box joined to a closed box subjected to torsional loading. A stiff bulkhead and a flexible bulkhead were tested at the discontinuity and the results were compared to a previously published theory. Stress distribution was found to not be sensitive to bulkhead stiffness when the stiffness is large, but the calculations became sensitive to errors in estimating when the stiffness was small.
- Wind-Tunnel Investigation of Control-Surface Characteristics 3: A Small Aerodynamic Balance of Various Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0009 Airfoil
- Report presenting tests in the 4- by 6-foot vertical wind tunnel of an NACA 0009 airfoil with a 30-percent-chord flap with a small amount of aerodynamic balance. In the investigation, the effect of balance nose shape and gap at the nose of the flap has been determined. The results indicate that, in general, the lift effectiveness of the flap was unaffected by the addition of a small amount of aerodynamic overhang, and the balance effectiveness of the flap was increased.
- Wind Tunnel Investigation of Control-Surface Characteristics 11: Various Large Overhang and Internal-Type Aerodynamic Balances for a Straight- Contour Flap on the NACA 0015 Airfoil
- Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the characteristics of several different shaped overhang-type aerodynamic balances applied to a straight-contour flap mounted on an NACA 0015 airfoil. The flap with blunt-nose overhang was overbalanced throughout certain ranges of flap deflection. Results regarding precision, lift, flap hinge moments, pitching moment, and drag are provided.
- Wind-Tunnel Investigation of Control-Surface Characteristics 4: A Medium Aerodynamic Balance of Various Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0009 Airfoil
- Report presenting tests made in the 4- by 6-foot vertical wind tunnel of an NACA 0009 airfoil with a 30-percent-chord flap with a medium amount of aerodynamic overhanging balance. In this investigation, the effects of the shape of the flap-nose overhang and the gap at the nose of the flap have been determined. The results indicate that, generally, the lift effectiveness of the aerodynamically balanced flap was increased slightly over that of a plain flap when a blunt or medium flap nose was used on the balanced flap.
- Wind Tunnel Investigation of Control Surface Characteristics: [Part] 12 - Various Cover-Plate Alinements on the NACA 0015 Airfoil With a 30 Percent Chord Flap and Large Sealed Internal Balance
- Report presenting force-test measurements in two-dimensional flow made in the 4- by 6-foot vertical tunnel to determine the aerodynamic effects of changing the alignment of the cover plates on a sealed internally balanced flap. Manufacturing imperfections in the alignment of the cover plates with the airfoil contour may have serious effects on the resultant hinge moment of a flap with a sealed internal balance. Results regarding lift, flap hinge moments, pitching moment, and drag are provided.
- Wind-Tunnel Investigation of Control-Surface Characteristics 16: Pressure Distribution Over an NACA 0009 Airfoil With 0.30-Airfoil-Chord Beveled-Trailing-Edge Flaps
- Report discusses pressure-distribution tests of a plain flap with interchangeable beveled trailing edges on an NACA 0009 airfoil. The flap chord was 30 percent of the airfoil chord and the bevel chords were 15 and 20 percent of the flap chord. The purpose of these tests was to supply pressure-distribution data that may be used for structural and aerodynamic design of horizontal and vertical tail surfaces.
- Theory and preliminary flight tests of an all-movable vertical tail surface
- Report presenting flight testing of an improved type of all-movable tail surface. The particular arrangement tested provides control-free stability and a stable variation of the control forces during maneuvers. Results regarding rudder effectiveness, directional stability, rudder-free lateral motion, and rudder-free turns are provided.
- 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.
- 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.
- 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.
- Wind-tunnel investigation of control-surface characteristics II : a large aerodynamic balance of various nose shapes with a 30-percent-chord flap on an NACA 0009 airfoil
- Report presenting testing of an NACA 0009 airfoil with a 30-percent-chord flap with a 49.5-percent flap-chord balance with various nose shapes and two gaps. The results indicated that the flap is overbalanced when deflected, regardless of nose shape. Results regarding lift, hinge moment of flap, drag, pitching moment, and effect of differential balancing tab are provided.
- Wind tunnel investigation of control-surface characteristics 10: a 30-percent-chord plain flap with straight contour on the NACA 0015 airfoil
- Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the characteristics of an NACA 0015 airfoil equipped with a straight-contour plain flap with a chord 30 percent of the airfoil chord. Results regarding the lift, hinge moment of flap, pitching moment, and drag are provided.
- Wind-Tunnel Investigation of a Full-Span Retractable Flap in Combination With Full-Span Plain and Internally Balanced Ailerons on a Tapered Wing
- Report discusses the results of an investigation into a full-span retractable flap in combination with a full-span plain and internally balanced ailerons on a tapered wing of a typical fighter airplane.The flap was designed to improve lateral control during high lifts for landing and take-off. The effects on the maximum life coefficient, aileron effectiveness, estimated rates of roll, and stick forces are provided.
- Wind-tunnel tests of two tapered wings with straight leading edges and with constant-chord center sections of different spans
- Report presenting an investigation in the 19-foot pressure tunnel of two-tapered wings with NACA 230-series airfoil sections, straight leading edges, and constant-chord center sections. Lift, drag, and pitching-moment coefficients were determined for the plain wing and for each flap arrangement for a range of Reynolds numbers. The results indicated that the wing with the square center section has greater maximum lift coefficients and increments of maximum lift due to flap deflections than the wing with the rectangular center section.
- Wind-tunnel investigation of control-surface characteristics 6: a 30-percent-chord plain flap on the NACA 0015 airfoil
- Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel of the characteristics of an NACA 0015 airfoil equipped with a plain flap with a chord 30 percent of the airfoil chord and a plain tab with a chord 20 percent of the flap chord. Results regarding lift, hinge moment of flap, pitching moment, drag, and tab characteristics are provided.
- 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.
- Wind-tunnel investigation of control-surface characteristics 1: effect of gap on the aerodynamic characteristics of an NACA 0009 airfoil with a 30-percent-chord plain flap
- From Summary: "Tests have been made to determine the effect of a gap at the flap nose upon the aerodynamic section characteristics of an NACA 0009 airfoil with a plain flap and tab. The results are presented in the form of airfoil and flap section characteristics for several flap deflections, tab deflections, and for four sizes of gap."
- Wind-tunnel tests of spoilers on tail surfaces
- Report presenting wind-tunnel testing in two-dimensional and three-dimensional flow to investigate the aerodynamic characteristics of spoilers on tail surfaces for low-speed flight. Test results indicated that spoilers on tail surfaces showed little possibility of replacing conventional control surfaces. Results regarding a flap alone, rear spoiler alone, forward spoiler alone, forward spoiler and flap, and a combination of forward and rear spoilers on upper and lower surfaces in both types of flow are provided.
- Tests of a Linked Differential Flap System Designed to Minimize the Reduction in Effective Dihedral Caused by Power
- Report discusses the results of testing on a linked differential flap system upon the effective-dihedral characteristics of an airplane scale model. The negative dihedral changes caused by power can be materially reduced or eliminated by use of a differential flap system. The static directional stability also increased with differential flap action.
- Wind-Tunnel Investigation of an NACA 23021 Airfoil With a 0.32-Airfoil-Chord Double Slotted Flap
- Report discusses an investigation to determine the aerodynamic section characteristics of an NACA 23021 airfoil with a double slotted flap with a chord 32 percent of the airfoil chord with the flaps at various positions. The maximum section lift coefficient, profile-drag coefficient, flap positioning, and effects of deflecting or removing the lower lip are described.
- Wind-Tunnel Investigation of Perforated Split Flaps for Use as Dive Brakes on a Tapered NACA 23012 Airfoil
- Aerodynamic characteristics of a tapered NACA 23012 airfoil with single and double perforated split flaps have been determined in the NACA 7- by 10-foot wind tunnel. Dynamic pressure surveys were made behind the airfoil at the approximate location of the tail in order to determine the extent and location of the wake for several of the flap arrangements. In addition, computations have been made of an application of perforated double split flaps for use as fighter brakes. The results indicated that single or double perforated split flaps may be used to obtain satisfactory dive control without undue buffeting effects and that single or double perforated split flaps may also be used as fighter brakes. The perforated split flaps had approximately the same effects on the aerodynamic and wake characteristics of the tapered airfoil as on a comparable rectangular airfoil.
- Wind-Tunnel Development of a Plug-Type Spoiler-Slot Aileron for a Wing With a Full-Span Slotted Flap and a Discussion of Its Application
- Report presenting an investigation in the NACA 7- by 10-foot wind tunnel of several arrangements of a plug-type, spoiler-slot aileron on an NACA 23012 airfoil with a full-span slotted flap. The results indicated that a plug-type, spoiler-slot aileron probably has negligible drag in the neutral position and will provide satisfactory lateral control for airplanes equipped with full-span slotted flaps.
- Aerodynamic characteristics and flap loads of perforated double split flaps on a rectangular NACA 23012 airfoil
- From Introduction: "The results of the load tests and some additional aerodynamic characteristics of perforated double split flaps on a rectangular NACA 23012 airfoil are given in the present report."
- Wind-Tunnel Investigation of an NACA 23012 Airfoil With a 0.30-Airfoil-Chord Double Slotted Flap
- Report discusses the results of testing of flap position and deflection on the aerodynamic characteristics of a NACA 23012 airfoil with a double slotted flap with a chord 30 percent of the airfoil chord. The maximum lift coefficient, profile-drag coefficients, pitching-moment coefficients, lift, and drag are provided at several positions of the flap. The results were also compared to previous testing on several flap configurations.
- Pressure distribution over an airfoil with a balanced split flap
- Report presenting a pressure-distribution investigation conducted in the 4- by 6-foot vertical wind tunnel to determine the air loads on an airfoil with a 22.1-percent-chord balanced split flap. Results regarding section pressure distribution and aerodynamic section coefficients are provided.
- Hinge Moments of Sealed-Internal-Balance Arrangements for Control Surfaces 2: Experimental Investigation of Fabric Seals in the Presence of a Thin-Plate Overhang
- Report presenting tests in a seal test chamber to determine the hinge moments contributed by the fabric seal in an internal-balance arrangement employing a thin-plate overhang. The tests were performed with various widths of fabric sealing various widths of flap-nose gap, with a horizontal, a vertical, and a circular type of wing structure forward of the balance, and with various heights of balance chamber. Results regarding seal-profile photographs, desired seal-moment characteristics, experimental seal-moment characteristics, effect of the balance configuration on the seal-moment characteristics, comparison of analytical and experimental seal-moment characteristics, computation of seal-moment characteristics by the approximate method, and application of the data are provided.
- Hinge Moments of Sealed-Internal-Balance Arrangements for Control Surfaces 1: Theoretical Investigation
- Report presenting the results of a theoretical analysis of the hinge-moment characteristics of various sealed-internal-balance arrangements for control surfaces. The results of the investigation indicated that the most nearly linear control-surface hinge-moment characteristics can probably be obtained from a flexible seal over a narrow gap, which is so installed that the motion of the seal is restricted to a region behind the point of attachment of the seal to the wing structure.
- Wind-Tunnel Investigation of a Spoiler-Slot Aileron on an NACA 23012 Airfoil With a Full-Span Fowler Flap
- Report presenting an investigation of a spoiler-slot aileron on an NACA 23012 airfoil with a full-span 30-percent-chord Fowler flap. The static rolling, yawing, and hinge moments were determined for several angles of attack and flap deflections. The ineffective region could be eliminated by a provision in the aileron linkage that would automatically uprig the ailerons as the flap is deflected.
- Wind-tunnel investigation of 20-percent-chord plain and Frise ailerons on an NACA 23012 airfoil
- Report presenting an investigation of several modifications of 20-percent-chord plain and Frise ailerons on an NACA 23012 airfoil in the 7- by 10-foot wind tunnel. Static rolling, yawing, and hinge moments were determined for several angles of attack.
- Wind-Tunnel Investigation of an NACA 23012 Airfoil with a Handley Page Slat and Two Flap Arrangements
- Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil equipped with a Handley Page slat and a slotted and a split flap. The purpose of the investigation was to determine the aerodynamic section characteristics of the airfoil with and without flaps as affected by the location of the Handley Page slat. A range of slat-nose locations was investigated both with and without flaps at a constant slat gap.
- Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges
- Report presenting a chart for the values of the coefficient in the formula for the critical shear stress at which buckling may be expected to occur in an infinitely long flat plate with parallel edges. An approximate method for the evaluation of the critical shear stress when the elastic restraints on the two parallel edges are not equal is also presented.
- Wind-Tunnel Investigation of a Plain and a Slot-Lip Aileron on a Wing With a Full-Span Flap Consisting of an Inboard Fowler and an Outboard Slotted Flap
- Report presenting an investigation of a slot-lip aileron and a plain aileron, singly and in combination, on an NACA 23012 wing with a full-span flap. The characteristics of these lateral-control devices were essentially the same as those of similar devices on the wing with full-span NACA slotted flaps as tested in a previous investigation.
- A method for predicting the elevator deflection required to land
- Report presenting a method for predicting from basic airplane characteristics the elevator deflection required to maintain optimum landing attitude. Charts for evaluating the components of the equation for elevator deflection and a comparison of computed and measured values for 15 airplanes are included. The computed deflection is considered the minimum value required to maintain landing attitude due to variations in piloting technique.
- Full-scale tunnel investigation of the pressure distribution over the tail of the P-47B airplane
- Report presenting measurements made of the pressures of the tail surfaces of the Republic Aviation Corporation P-47B airplane in the full-scale tunnel. Pressures were measured over the horizontal and vertical tail surfaces for several angles of attack and angles of yaw with numerous control-surface deflections to provide a check on the design loads. Results regarding the normal-force coefficients and predictions of forces on horizontal tail surfaces are provided.
- Wind-tunnel tests of hinge-moment characteristics of spring-tab ailerons
- Report presenting testing in the stability tunnel of two types of spring tab used as balances on a partial-span plain aileron. The tabs were connected to a spring located in the control system so that tab deflection was dependent on the control force.
- Wind tunnel investigation of a plain aileron with various trailing-edge modifications on a tapered wing 2: ailerons with thickened and beveled trailing edges
- Report presenting an investigation in the 7- by 10-foot tunnel of various modifications to the trailing edge of a 0.155-chord plain aileron on a semispan model of the tapered wing of a fighter airplane. The stick forces and rates of roll were estimated for a fighter airplane with the plain and modified ailerons.
- Wind-Tunnel Investigation of a Plain Aileron with Various Trailing-Edge Modifications on a Tapered Wing 3: Ailerons with Simple and Spring-Linked Balancing Tabs
- Aerodynamics data are obtained for the design of linked balancing tabs and effect of varied tab span and location to produce suitable lateral control characteristics with reasonable stick pressures for high-speed aircraft. Simple and spring-linked balancing tabs may considerably reduce control pressures if aileron system is designed for low maximum aileron deflection. Spring-linked tabs also decrease variation of stick pressure with speed and impart better controlllability at low speeds.
- 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.
- Wind-Tunnel Investigation of the Characteristics of Blunt-Nose Ailerons on a Tapered Wing
- Characteristics are determined for various modifications of 0.155-chord blunt-nose aileron on semispan model of tapered fighter plane wing. Ailerons with 40 percent nose balance reduced high-speed stick forces. Increased balance chord increases effectiveness and reduces high-speed stick forces. Increased balance chord increases effectiveness and reduces adverse effects of gap at aileron hose. Increase of nose radii increased negative slope of curve hinge-movement coefficient plotted against deflection. Extended deflection range decreased aileron effectiveness for small deflections but increased it at large deflections. Peak pressures at noses of ailerons are relatively high at moderate deflections.
- 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.
- Characteristics of beveled-trailing-edge elevators on a typical pursuit fuselage at altitudes simulating-normal flight and spin conditions
- Report presenting lift and elevator hinge-moment characteristics were measured on horizontal tail provided with elevators having three different beveled trailing edges. Results regarding fuselage alone and fuselage interference, lift characteristics of fuselage-tail combination, elevator hinge-moment characteristics, drag, and comparison with data from two-dimensional-flow tests are provided.
- Some Systematic Model Experiments of the Bow-Spray Characteristics of Flying-Boat Hulls Operating at Low Speeds in Waves
- Report discusses the results of testing on several models of flying boats, the XPB2M-1, the XPBB-1, the JRM-1, and 11 other models to determine the effect of bow form on the amount of spray thrown onto the windshield of a flying boat in rough water. Several recommendations for reducing the height and volume of spray are provided. Any change in the hull form that softens the impact between the hull and waves seems to reduce the spray.
- General resistance tests on flying-boat hull models
- Report re-examining known procedures for handling general resistance testing on flying-boat hull models, with particular attention paid to saving test time and improving the usefulness of the results to designers. While specific testing will likely always be needed, the procedures given in the report for condensing resistance data should make data analysis easier to apply to design.
- 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.
- Flight Investigation of Boundary-Layer and Profile-Drag Characteristics of Smooth Wing Sections of a P-47D Airplane
- "In Mach range of 0.25 - 0.69, boundary-layer measurements were made on upper wing surface at 25% semi-span, pressure-distribution measurements made on upper surface at 63% semi-span, and wake surveys made at 63% semi-span. The minimum profile-drag coefficient of 0.0062 was indicated for smooth section at 63% semi-span. Critical mach number was exceeded by 0.04, but no compressibility shocks appeared. In slipstream, boundary layer transition occurred as far back as 20% chord on upper surface at low lift coefficients" (p. 1).
- Tire friction coefficients and their relation to ground-run distance in landing
- Report presenting a summary of published information on braking friction coefficients. Analysis indicates that the magnitude of the friction coefficient available will affect the technique required for obtaining the shortest ground run only under extreme conditions.
- The Effect of Various Surface Conditions on Press Fits of Steel Bushings and 17S-T Aluminum-Alloy Fittings
- Report presenting testing of specimens of 17S-T aluminum-alloy fittings with pressed-in steel bushings for various surface conditions. The surface conditions tested included bare surfaces, aonidcal coating and steel cadmium-plate, and one surface treated and the other bare, both without lubrication and with Gredag No. 83 as a lubricant. The calculated coefficients of friction for the various press fits for the investigation ranged from 0.33 for the unlubricated contact of bare steel and aluminum to 0.09 for the specimen with the unlubricated cadmium-plated bushing.
- An investigation of aircraft heaters 22: measured and predicted performance of a fluted-type exhaust gas and air heat exchanger
- Report presenting data on the thermal performance and static and total pressure drop characteristics of a fluted-type exhaust gas and air heat exchanger. Results regarding heat transfer, pressure drop, and non-isothermal pressure drop are provided.