| 出版: | Washington, D.C. : Carnegie Institution of Washington |
| 出版: | [Washington : U. S. Govt. Print. Off.] |
| 附註: | On cover: Bureau of Naval Personnel. "Navpers 16127." |
| 出版: | [Pensacola] : |
| 出版: | Washington, D.C. : U.S. G.P.O. |
| 附註: | "NAVPERS 15006." Includes a Supplement to the code for classifying naval officers' qualifications, published, February 1, 1945 "April 1, 1944."--cover. |
| 出版: | [n.p.] : |
| 出版: | New York : G. P. Putnam's sons |
| 出版: | [Washington] : |
| 附註: | "Reprint of Wave report no.49, Scripps Institution of Oceanography, which contains a revision of certain portions of the original publication, Breakers and surf." Accompanied by "Supplement." (16 p. illus. 28 cm.) Published: Washington, 1950 |
| 出版: | Berkeley, Los Angeles : University of California Press |
| 附註: | "Contribution from the Scripps institution of oceanography, new series, no. 226." "Literature cited": p. 282-288 |
| 出版: | [Washington, D.C.] : Published by the Hydrographic Office under the authority of the Secretary of the Navy, [1944] |
| 出版: | Washington : Carnegie Institution of Washington |
| 出版: | [Washington, D.C.? : |
| 附註: | "Confidential." Reproduced from typewritten copy. Duplicate set of plates laid in. |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Report date November 1944."FU "Originally issued November 1944 as Restricted Bulletin L4I06."FU "Report no. L-92."FU Summary: Tests of a single-engine scout-bomber airplane showed that the rudder deflection required for trim at low speed in the critical wave-off condition may be reduced approximately 10À by a lateral shift of the center of gravity equal to 1.8 percent of the wing span. The reduction in rudder deflection required for trim consists of the rudder deflection required to offset yawing moments from the ailerons and from the component of the weight in the direction of the longitudinal axis and the rudder deflection required to hold the sideslip angle necessary to maintain straight flight. The effect of the lateral loading must be taken into account in tests to determine the adequacy of the rudder for trim. The lateral center-of-gravity location is also important in the service operation of airplanes because, by suitable distribution of the useful load in the wings, the ability of the rudder to trim the airplane in critical power-on conditions may be markedly improved. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Report date July 1944."FU "Originally issued July 1944 as Advance Restricted Report L4G05."FU "Report no. L-135."FU Summary: A method, based directly on the so-called [epsilon]-curve method published originally in 1931 in NACA Report No. 411, is presented for use in making modifications to the shape and pressure distribution of a given air-foil. In particular, it may be desirable to remove excessive irregularities or local peaks in the distribution. In this process it may be required that certain parameters of the airfoil be kept unchanged; for instance, the angle of zero lift, the ideal lift coefficient, or the moment coefficient. From an academic viewpoint, an altered distribution cannot be "prescribed" because compliance with the requirement of maintaining a Laplacian flow field is involved. A prescribed distribution can therefore not be obtained by iteration. The process, however adequate, is necessarily one of qualitative modifications. Several numerical examples illustrating the use of the method are given in the appendix. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Report date March 1944."FU "Originally issued March 1944 as Memorandum Report."FU "Report no. L-133."FU Summary: At the request of the Army Air Forces, Materiel Command, the NACA is assisting in the development of a type GB-5 controllable glide bomb equipped with a "target-seeking" device. In order to measure the stability and control characteristics of the bomb in its original condition and with various modifications a 1/5-scale model has been tested on the six-component balance in the free-flight tunnel. The tests included the development of suitable means for altering the effective dihedral and the directional stability by simple structural modification, the development of a device capable of altering the lift-drag ration of the bomb without changing the angle of attack, and the measurement of the rolling- and yawing-moment characteristics of the ailerons. The results of these tests are presented herein. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Originally issued October 1944 as Advance Restricted Report L4F06."FU Includes bibliographic references (p. 4). Summary: 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. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Originally issued May 1944 as Advance Confidential Report L4E01."FU Includes bibliographic references (p. 13-16). Summary: A considerable amount of two- and three-dimensional data on the effectiveness of ailerons without exposed overhang balance has been collected and analyzed. The trends indicated by the analysis have been summarized in the form of a few approximate rules concerning the effectiveness parameter [Pyramid symbol[alpha]/[Pyramid symbol[delta] (at constant lift): Thickening and beveling the trailing edge (as measured by the trailing-edge angle ¢) will generally reduce the effectiveness about 0.3 percent per degree of bevel for ailerons sealed at the hinge axis and about 0.6 percent per degree of bevel for unsealed ailerons. A 0.005c gap at the hinge axis usually reduces the effectiveness approximately 17 percent for flap chord ratios of 0.2. This percentage increases as the flap chord ratio is reduced. The effectiveness is about 14 percent lower at aileron deflections of 20À than at aileron deflections of 10À. At large angles of attack (a = 10À) and for chord ratios of about 0.2, positively deflected ailerons are approximately 20 percent less effective than negatively deflected ailerons. The deflection of partial-span flaps has no consistent effect on the effectiveness. Increases in Mach number and forward movement of the transition point decrease the aileron effectiveness. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Report date August 1944."FU "Originally issued August 1944 as Advance Confidential Report L4H05."FU "Report no. L-26."FU Summary: Performance calculations are presented for a typical helicopter rotor in which three types of airfoil section were successively used. The types represented are the rough conventional, the smooth conventional, and the laminar-flow or low-drag sections as developed for helicopter use. The performance items covered are rotor thrust for fixed power in hovering, range and endurance at cruising speed, and power required at a relatively high forward speed. Contours showing the conditions of operation encountered by the blade section and weighting curves showing the relative importance of the various section angles of attack for specified flight conditions are included as an aid in the interpretation of the results. The calculations indicated that the use of a smooth conventional section will result in marked performance gains throughout the flight range. Definite, though smaller, additional gains in take-off weight and in range and endurance may be realized by the use of a low-drag section. At high forward speeds or at moderate forward speeds and high loadings, however, losses are indicated for the low-drag sections in contrast with the smooth conventional sections. It is demonstrated that, if these losses are to be avoided, the low-drag sections must be designed to avoid the extreme rise in drag coefficient at the higher angles of attack which is characteristic of the low-drag sections now available for use in helicopters. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Originally issued October 1944 as Advance Restricted Report L4I11f."FU Includes bibliographic references (p. 13). Summary: Force-test measurements have been made in the Langley 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 0009 semispan tail surface of rectangular plan form equipped with flaps of various nose shapes and overhangs. The flap chord was 30 percent of the airfoil chord. A few tests were made to determine the effectiveness of a balancing tab on various flap arrangements. The test results indicated that the slope of the lift curve was affected little by the amount of overhang and the balance nose shape but was increased by sealing the gap at the flap nose. At zero angle of attack, the variation of lift with flap deflection for the sealed-gap condition was the same as or slightly greater than for the unsealed-gap condition. The change in the hinge-moment coefficient with angle of attack or with flap deflection generally was made more negative with sealing the gap. The effectiveness of the balancing tab in reducing the flap hinge-moment coefficients was approximately the same for both the sealed plain flap and the unsealed 35-percent-flap-chord elliptical overhang; also, the variation of lift coefficient with tab deflection was about equal for the plain flap and for the flap with aerodynamic balance. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Report date October 1944."FU "Originally issued October 1944 as Advance Restricted Report L4J16."FU "Report no. L-60."FU Includes bibliographic references (p. 8). Summary: An investigation was made to determine the aerodynamic effects of horn balances with various plan forms and of guards on a horizontal tail surface. The results indicate that rounding the adjacent horn and stabilizer edges caused neglibible changes in the aerodynamic characteristics, except for the changes resulting from the decrease in the area momeent of the horn. The use of guards mounted between the stabilizer and horn was found to increase the slope of the lift curves with angle of attack or with elevator deflection. The negative slopes of the curves of hinge moment against angle of attack and elevator deflection increased as the guard area was increased. Also available in electronic format.FU |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Originally issued May 1944 as Advance Restricted Report L4E22."FU "Report no. L-80."FU Includes bibliographic references (p. 11). Summary: The advent of dual-rotating propellers has created a need for information concerning the effect of the number of blades of the front and rear propellers, relative rotational speeds, and small changes in the blade angles of the rear propeller. Results of aerodynamic tests of seven-blade propellers, which were considered as a possible arrangement to avoid vibration difficulties, are presented herein. Variations of relative blade angle and rotational speeds of the front and rear components of a six-blade dual-rotating propeller were also investigated. The test program was an extension of previous work on dual-rotating propellers at the NACA propeller-research tunnel; the propeller blades and test body were those used in the previous tests. The results indicated that envelope efficiencies of a seven-blade propeller with three blades in the front hub and four in the rear were form 0 to 1 1/2 percent lower than envelope efficiencies for the six-blade dual-rotating propeller; four blades in the front hub and three in the rear resulted in efficiencies 1/2 to 3 1/2 percent lower than those obtained with the six-blade propeller. This conclusion applies to blade-angle settings of the front and rear propellers to absorb equal power at peak efficiency when the rotational speeds were held equal. Also available in electronic format.FU |
| 出版: | Cleveland, OH : Aircraft Engine Research Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Originally issued September 1944 as Restricted Bulletin E4I27."FU "Report no. E-72."FU Includes bibliographic references (p. 7-8). Summary: An investigation has been made of the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. Pressure-time recoreds obtained show that injection of water at 60À B.T.C. on the compression stroke at a water-fuel ratio of 0.3 rendered M-3 fuel as good as S-3 fuel from an antiknock consideration. The optimum crank angle for injection of water into the end zone was found to be critical. As the injection angle was increased beyond the optimum, the quantity of water required to suppress knock increased to 3.6 water-fuel ratio at 132À B.T.C. The water quantity could not be increased beyond 3.6 water-fuel ration because of injection-pump limitations; however, a further increase in the injection angle up to the earliest angle obtainable, which was 20À A.T.C. on the intake stroke, continuously increased the knock intensity. The engine operating conditions of the tests did not simulate those encountered in flight, especially with regard to the operating speed of 570 rpm. For this reason the results should only be regarded as of theoretical importance until further investigation has been made. Also available in electronic format.FU |
| 出版: | Washington, D.C. : War Dept. |
| 附註: | "United States of America, War Office." "23 September 1944." |
| 出版: | Langley Field, VA : Langley Memorial Aeronautical Laboratory |
| 附註: | "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."FU "Report date May 1944."FU "Originally issued May 1944 as Advance Restricted Report L4E25."FU "Report no. L-12."FU Includes bibliographic references (p. 12). Summary: The results of tests of a circular fuselage with various combinations of tail lengths and vertical tail surfaces with and without the horizontal tail surface in the 6- by 6-foot test section of the NACA stability tunnel are reported in the form of diagrams of variation of coefficients of lateral force and yawing moment with angle of yaw and angle of attack. The results of these tests indicated that the change in the unstable yawing moment of the fuselage alone due to increased tail length did not appreciably affect the yawing moment of a fuselage and vertical-tail combination. The addition of a horizontal tail increased the efficiency of the vertical tail in normal-flight attitudes and in the region of negative angles of attack. Existing methods of computing tail effectiveness gave results within «7 percent of the measured values for the cases computed. Also available in electronic format.FU |
| 出版: | Washington : U. S. Govt. print. off. |
| 出版: | Washington : U.S. G.P.O. |
| 附註: | Schuyler Otis Bland, chairman. |
| 出版: | Washington : U. S. Govt. print. off. |
| 附註: | v.1.May 25,26,1944.--v.2.June 13,14,15,1944 |
| 出版: | [Washington] : Office of the Chief of Naval Operations, Navy Dept. |
| 出版: | Washington : U. S. Govt. print. off. |
| 出版: | Washington : U.S. Govt. print. off. |
| 附註: | Schuyler Otis Bland, chairman. |
| 出版: | [Washington, D.C.] : United States Dept. of the Interior, Fish and Wildlife Service |
| 出版: | [Washington] : Office of the chief of naval operations, Navy dept. |