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Dynamic stress calculations for two airplanes in various gusts

Description: Report presenting a series of calculations made to determine the probable dynamic wing stress of two large airplanes in atmospheric gusts. The results indicate that in both isolated and repeated gusts of probable occurrence, the dynamic overstress is about 10 percent when referred to the present static design standard.
Date: September 1941
Creator: Pierce, Harold B.
Partner: UNT Libraries Government Documents Department

An investigation of diffuser-resistance combinations in duct systems

Description: Report presenting an investigation to determine the properties of diffuser-resistance combinations. The work applies to the design of airplane cooling ducts in which air is expanded in front of resistances, such as radiators, oil coolers, intercoolers, or the cylinders of an air-cooled engine.
Date: February 1942
Creator: McLellan, Charles H. & Nichols, Mark R.
Partner: UNT Libraries Government Documents Department

Investigation of flow through an intercooler set at various angles to the supply duct

Description: Report presenting an investigation to determine the flow losses that occur as a result of locating the axis of an intercooler at various angles with respect to the supply-duct axis and also to determine the flow pattern throughout the intercooler. The flow losses were found to be small for angles of inclination up to about 70 degrees. The distribution of flow through the intercooler also appeared to be fairly uniform up to about this angle.
Date: April 1942
Creator: Nichols, Mark R.
Partner: UNT Libraries Government Documents Department

Nitrided-steel piston rings for engines of high specific power

Description: Report presenting testing of several designs of nitrided-steel piston rings under variable conditions of output. Testing indicated the importance of good surface finish and conformity of the ring to the bore. Results regarding temperature tests, single-cylinder-engine tests, and multicylinder-engine tests are provided.
Date: April 1944
Creator: Collins, John H., Jr.; Bisson, Edmond E. & Schmiedlin, Ralph F.
Partner: UNT Libraries Government Documents Department

A general representation for axial-flow fans and turbines

Description: From Summary: "A general representation of fan and turbine arrangements on a single classification chart is presented which is made possible by a particular definition of the stage of an axial-flow fan or turbine. Several unconventional fan and turbine arrangements are indicated and the applications of these arrangements are discussed."
Date: June 1945
Creator: Perl, W. & Tucker, M.
Partner: UNT Libraries Government Documents Department

Effect of progressive ring failure on piston destruction

Description: Report presenting an investigation of the effect of progressive ring failure on piston life. Two endurance runs were conducted on an Allison single-cylinder engine at high power output until destruction of the pistons occurred at 33.1 and 84.25 hours.
Date: February 1945
Creator: Tauschek, Max J. & Corrington, Lester C.
Partner: UNT Libraries Government Documents Department

Maximum permissible engine performance of eight representative fuels of 100-octane number

Description: Report presenting knock-limited performance tests made with eight representative fuels rated at 100-octane number using the CFR aviation method. All eight fuels were mixtures of representative blending agents and bases. Results regarding the effect of inlet-temperature air changes, effect of octane numbers in a full-scale single-cylinder engine, effect of addition of aromatics to the fuels, and type of spark plug used are provided.
Date: January 1942
Creator: Rothrock, Addison M.; Biermann, Arnold E. & Corrington, Lester C.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics 7: a medium aerodynamic balance of two nose shapes used with a 30-percent-chord flap on an NACA 0015 airfoil

Description: 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.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: August 1941
Creator: Sears, Richard I. & Hoggard, H. Page, Jr.
Partner: UNT Libraries Government Documents Department

Small-orifice tubes for minimizing dilution in exhaust-gas samples

Description: Report presenting an investigation to find a means of obtaining undiluted exhaust-gas samples from a Wright R-2600-B aircraft engine equipped with short individual stacks. Preliminary tests to aid in determining the best design, location, and orientation of orifices ranging in size. Results regarding the Briggs & Stratton engine tests and Wright aircraft engine tests are provided.
Date: February 1943
Creator: Cook, Harvey A. & Olson, Walter T.
Partner: UNT Libraries Government Documents Department

Wind tunnel investigation of control-surface characteristics 10: a 30-percent-chord plain flap with straight contour on the NACA 0015 airfoil

Description: 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.
Date: September 1942
Creator: Hoggard, H. Page, Jr.
Partner: UNT Libraries Government Documents Department

Wind tunnel investigation of control surface characteristics 12: various cover-plate alinements on the NACA 0015 airfoil with a 30 percent chord flap and large sealed internal balance

Description: 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.
Date: January 1943
Creator: Hoggard, H. Page, Jr.
Partner: UNT Libraries Government Documents Department

A semi-rational criterion for unsymmetrical gust loads

Description: Report presenting a discussion of the problem of establishing a rational unsymmetrical gust load criterion from available data on gust structure and it is indicated that the problem cannot be solved at the present state of knowledge without more analysis.
Date: August 1941
Creator: Rhode, Richard V. & Pearson, Henry A.
Partner: UNT Libraries Government Documents Department

Characteristics of beveled-trailing-edge elevators on a typical pursuit fuselage at altitudes simulating-normal flight and spin conditions

Description: 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.
Date: December 1942
Creator: Gillis, Clarence L.
Partner: UNT Libraries Government Documents Department

Analysis of Effect of Rolling Pull-Outs on Wing and Aileron Loads of a Fighter Airplane

Description: An analysis was made to determine the effect of rolling pull-out maneuvers on the wing and aileron loads of a typical fighter airplane, the P-47B. The results obtained indicate that higher loads are imposed upon wings and ailerons because of the rolling pull-out maneuver, than would be obtained by application of the loading requirements to which the airplane was designed. An increase of 102 lb or 15 percent of wing weight would be required if the wing were designed for rolling pull-out maneuver. It was also determined that the requirements by which the aileron was originally designed were inadequate.
Date: March 1946
Creator: Pearson, Henry A. & Aiken, William S., Jr.
Partner: UNT Libraries Government Documents Department

Effects of propeller operation and angle of yaw on the distribution of the load on the horizontal tail surface of a typical pursuit airplane

Description: Report presenting measurements in the full-scale tunnel of the pressure distribution over the horizontal tail surface of a typical pursuit airplane in order to determine the effects of propeller operation and angle of yaw on the tail load distribution. Most of the tests were made with the propeller operating to simulate climb conditions, high-speed dives, and pull-ups to various normal accelerations for a range of angles of yaw. Results regarding chordwise pressure distributions, spanwise distributions of normal-force coefficient, airflow measurements, and tail-load asymmetry are provided.
Date: February 1944
Creator: Sweberg, Harold H. & Dingeldein, Richard C.
Partner: UNT Libraries Government Documents Department

Full-scale tunnel investigation of the pressure distribution over the tail of the P-47B airplane

Description: 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.
Date: May 1943
Creator: Dingeldein, Richard C.
Partner: UNT Libraries Government Documents Department

Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges

Description: 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.
Date: November 1943
Creator: Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department

Bending and shear stresses developed by the instantaneous arrest of the root of a cantilever beam rotating with constant angular velocity about a transverse axis through the root

Description: From Summary: "A theoretical investigation was made of the behavior of a cantilever beam in rotational motion about a transverse axis through the root determining the stresses, the deflections, and the accelerations that occur in the beam as a result of the arrest of motion. The equations for bending and shear stress reveal that, at a given percentage of the distance from root to tip and at a given trip velocity, the bending stresses for a particular mode are independent of the length of the beam and the shear stresses vary inversely with the length. When examined with respect to a given angular velocity instead of a given tip velocity, the equations reveal that the bending stress is proportional to the length of the beam whereas the shear stress is independent of the length."
Date: June 1945
Creator: Stowell, Elbridge Z.; Schwartz, Edward B. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department

Tensile Tests of NACA and Conventional Machine-Countersunk Flush Rivets

Description: An investigation was conducted to determine and compare the tensile strength of NACA and conventional machine-countersunk flush rivets of several rivet-head angles and varying countersunk depth. The results of the investigation are presented in the form of curves that show the variation of the tensile strength of the rivet with the ratio of the sheet thickness to the rivet diameter. For the same rivet-head angle and for a given angle of c/d, the NACA rivets developed higher tensile strength than the conventional rivets.
Date: October 1944
Creator: Bartone, Leonard M. & Mandel, Merven W.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 22: measured and predicted performance of a fluted-type exhaust gas and air heat exchanger

Description: 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.
Date: April 1945
Creator: Boelter, L. M. K.; Guibert, A. G.; Rademacher, J. M. & Romie, F. E.
Partner: UNT Libraries Government Documents Department

Langley full-scale tunnel investigation of the factors affecting the directional stability and trim characteristics of a fighter-type

Description: Report presenting testing in the full-scale tunnel of the Grumman XF6F-4 airplane to investigate the factors that affect the directional stability and trim characteristics of a typical fighter-type airplane. Eight representative flight conditions were investigated in detail.
Date: November 1945
Creator: Sweberg, Harold H.; Guryansky, Eugene R. & Lange, Roy H.
Partner: UNT Libraries Government Documents Department