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Theoretical analysis of hydrodynamic impact of a prismatic float having freedom in trim

Description: From Summary: "Equations which include freedom in trim are derived for hydrodynamic impact of a non-chine-immersed, prismatic float forebody having a V-bottom and a transverse step. These equations are an extension of previously published fixed-trim theory, and a method of solution is indicated by which time histories of vertical, horizontal, and angular displacement, velocity, and acceleration can be obtained. Comparisons of specific solutions of the equations with corresponding fixed-trim solutions are presented."
Date: June 1952
Creator: Miller, Robert W.
Partner: UNT Libraries Government Documents Department

Air force and three moments for F-5-L Seaplane

Description: From Introduction: "A model of the F-5-L seaplane was made, verified, and tested at 40 miles an hour in the 8' x 8' tunnel for lift and drag, also for pitching, yawing and rolling moments. Subsequently, the yawing moment test was repeated with a modified fin. The results are reported without VL scale correction."
Date: February 1922
Partner: UNT Libraries Government Documents Department

Analysis and modification of theory for impact of seaplanes on water

Description: From Summary: "An analysis of available theory on seaplane impact and a proposed modification thereto are presented. In previous methods the overall momentum of the float and virtual mass has been assumed to remain constant during the impact but the present analysis shows that this assumption is rigorously correct only when the resultant velocity of the float is normal to the keel."
Date: August 20, 1945
Creator: Mayo, Wilbur L.
Partner: UNT Libraries Government Documents Department

Analysis of planing data for use in predicting hydrodynamic impact loads

Description: From Introduction: "The magnitude of hydrodynamic loads experienced by seaplanes during a landing impact has been investigated experimentally and theoretically by the National Advisory Committee for Aeronautics. The results as reported in references 1 and 2 provide a rational means of determining loads on conventional V-bottom hulls in a step landing."
Date: August 1948
Creator: Steiner, Margaret F.
Partner: UNT Libraries Government Documents Department

Hydrodynamic impact of a system with a single elastic mode I : theory and generalized solution with an application to an elastic airframe

Description: Solutions of impact of a rigid prismatic float connected by a massless spring to a rigid upper mass are presented. The solutions are based on hydrodynamic theory which has been experimentally confirmed for a rigid structure. Equations are given for defining the spring constant and the ratio of the sprung mass to the lower mass so that the two-mass system provides representation of the fundamental mode of an airplane wing. The forces calculated are more accurate than the forces which would be predicted for a rigid airframe since the effect of the fundamental mode on the hydrodynamic force is taken into account. In a comparison of the theoretical data with data for a severe flight-test landing impact, the effect of the fundamental mode on the hydrodynamic force is considered and response data are compared with experimental data.
Date: March 17, 1947
Creator: Mayo, Wilbur L.
Partner: UNT Libraries Government Documents Department

Hydrodynamic tests for determining the take-off characteristics of seaplanes

Description: The resistance of water, even at low speeds, may be such as to render it impossible to take off. For this type of aircraft, it is therefore especially important to determine the take-off characteristics. A new and simple graphical method is given and appears to be the only one for the complete solution of the problem.
Date: May 1923
Creator: Verduzio, R.
Partner: UNT Libraries Government Documents Department

An Investigation of Hydrofoils in the NACA Tank 1: Effect of Dihedral and Depth of Submersion

Description: Tests were conducted on hydrofoil assemblies approximating an arrangement for use under seaplanes or surface boats. A series of hydrofoils, each supported by two struts, was towed at various depths ranging from partial submersions to a depth of 5-chord lengths. At depths greater than 4 or 5 chords, the influence of the surface of the water is small; hydrofoils operating at low speed will have characteristics similar to those of airfoils of the same section.
Date: September 1942
Creator: Benson, James M. & Land, Norman S.
Partner: UNT Libraries Government Documents Department

Additional abstracts pertaining to seaplanes

Description: From Summary: "About 500 additional references pertaining to hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings:GENERAL INFORMATION, HYDROSTATICS, HYDRODYNAMICS, AERODYNAMICS, OPERATION, and RESEARCH. The compilation is an extension of NACA RM No. L6I13, entitled "Abstracts Pertaining to Seaplanes," by Jerold M. Bidwell and Douglas A. King. An author index and a subject index are included."
Date: March 9, 1948
Creator: Bidwell, J. M. & King, D. A.
Partner: UNT Libraries Government Documents Department

The 1926 German seaplane contest

Description: The report discusses the problem of rating the various seaplane designs from the 1926 seaplane contest. The whole process of rating consists in measuring the climbing speed, flying weight and carrying capacity of a seaplane and then using these data as the basis of a construction problem.
Date: March 1928
Creator: Seewald, F; Blenk, H & Liebers, F
Partner: UNT Libraries Government Documents Department

Abstracts pertaining to seaplanes

Description: Report discussing about 400 references pertaining to the hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings.
Date: July 24, 1947
Creator: Bidwell, Jerold M. & King, Douglas A.
Partner: UNT Libraries Government Documents Department

An experimental investigation of the scale relations for the impinging water spray generated by a planing surface

Description: Report presenting an experimental investigation to determine the scale effects of the forces from water spray generated by a flat rectangular planing surface and impinging on a collector plate representative of an aerodynamic surface or other part of a water-based airplane. Lift and drag forces on the flat rectangular planing surface and the spray-collector plate were measured.
Date: February 1956
Creator: McBride, Ellis E.
Partner: UNT Libraries Government Documents Department

Appreciation and determination of the hydrodynamic qualities of seaplanes

Description: Report presenting a summary of the hydrodynamic qualities of interest in the normal operation of a seaplane, established over a period of years by model testing and by some knowledge of full-size operation. Results regarding longitudinal stability and control, landing stability, seaworthiness, performances, and lateral stability and control are provided.
Date: May 1947
Creator: Parkinson, John B.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Partner: UNT Libraries Government Documents Department

Hydrodynamic impact loads in rough water for a prismatic float having an angle of dead rise of 30 degrees

Description: Report presenting an investigation in the impact basin to determine the hydrodynamic impact loads in rough water for a prismatic-float forebody with an angle of dead rise of 30 degrees. Testing occurred at fixed trim and each impact occurred into a 2-foot-high wave at 60, 45, or 30 feet in length. Results regarding the calculation of rough-water loads and comparison with smooth-water conditions are provided.
Date: December 1948
Creator: Miller, Robert W.
Partner: UNT Libraries Government Documents Department

The aerodynamic drag of five models of side floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

Description: The drag of five models of side floats was measured in the N.A.C.A. 7- by 10-foot wind tunnel. The most promising method of reducing the drag of floats indicated by these tests is lowering the angle at which the floats are rigged. The addition of a step to a float does not always increase the drag in the flying range, floats with steps sometimes having lower drag than similar floats without steps. Making the bow chine no higher than necessary might result in a reduction in air drag because of the lower angle of pitch of the chines. Since side floats are used formally to obtain lateral stability when the seaplane is operating on the water at slow speeds or at rest, greater consideration can be given to factors affecting aerodynamic drag than is possible for other types of floats and hulls.
Date: December 1938
Creator: House, R. O.
Partner: UNT Libraries Government Documents Department

Bibliography and review of information relating to the hydrodynamics of seaplanes

Description: Report presenting a bibliography and review of information related to the hydrodynamics of seaplanes. Characteristics of conventional hulls and floats are discussed to show the effects upon performance of changes in design parameters like dead rise, depth of step, and angle of afterbody keel. Other topics include floats, lateral stabilizers, aerodynamic and propulsive considerations, unconventional configurations, hydrofoils, and piloting and handling.
Date: September 1945
Creator: Benson, James M. & Bidwell, Jerold M.
Partner: UNT Libraries Government Documents Department

Characteristics of a boat type seaplane during take-off

Description: This report, on the planing and get-away characteristics of the F-5-L, gives the results of the second of a series of take-off tests on three different seaplanes conducted by the National Advisory Committee for Aeronautics at the suggestion of the Bureau of Aeronautics, Navy Department. The single-float seaplane was the first tested and the twin-float seaplane is to be the third. The characteristics of the boat type were found to be similar to the single float, the main difference being the increased sluggishness and relatively larger planing resistance of the larger seaplane. At a water speed of 15 miles per hour the seaplane trims aft to about 12 degrees and remains in this angular position while plowing. At 2.25 miles per hour the planing stage is started and the planing angle is immediately lowered to about 10 degrees. As the velocity increases the longitudinal control becomes more effective but over control will produce instability. At the get-away the range of angle of attack is 19 degrees to 11 degrees with velocities from the stalling speed through about 25 per cent of the speed range.
Date: January 1926
Creator: Crowley, J. W., Jr. & Ronan, K. M.
Partner: UNT Libraries Government Documents Department

Characteristics of a twin-float seaplane during take-off

Description: This report presents the results of an investigation of the planing and get-away characteristics of three representative types of seaplanes, namely, single float, boat, and twin float. The experiments carried out on the single float and boat types have been reported on previously. This report covers the investigation conducted on the twin-float seaplane, the DT-2, and includes as an appendix, a brief summary of the results obtained on all three tests. At low-water speeds, 20 to 30 miles per hour, the seaplane trims by the stern and has a high resistance. Above these speeds the longitudinal control becomes increasingly effective until, with corresponding speeds of 56 to 46 miles per hour. It was further determined that an increase in the load caused little if any change in the water speed at which the maximum angle and resistance occurred, but that it did produce an increase in the maximum angle.
Date: January 1927
Creator: Crowley, John W., Jr. & Ronan, K. M.
Partner: UNT Libraries Government Documents Department

Characteristics of a single float seaplane during take-off

Description: At the request of the Bureau of Aeronautics, Navy Department, the National Advisory Committee for Aeronautics at Langley Field is investigating the get-away characteristics of an N-9H, a DT-2, and an F-5l, as representing, respectively, a single float, a double float, and a boat type of seaplane. This report covers the investigation conducted on the N-9H. The results show that a single float seaplane trims aft in taking off. Until a planing condition is reached the angle of attack is about 15 degrees and is only slightly affected by controls. When planing it seeks a lower angle, but is controllable through a widening range, until at the take-off it is possible to obtain angles of 8 degrees to 15 degrees with corresponding speeds of 53 to 41 M. P. H. or about 40 per cent of the speed range. The point of greatest resistance occurs at about the highest angle of a pontoon planing angle of 9 1/2 degrees and at a water speed of 24 M. P. H.
Date: January 1925
Creator: Crowley, J. W., Jr. & Ronan, K. M.
Partner: UNT Libraries Government Documents Department

An Investigation of the Hydrodynamic Characteristics of a 1/10-Size Powered Dynamic Model of the Martin M-267 Patrol-Type Seaplane with Two Forebody Configurations: TED No. NACA DE 376

Description: Report presenting an investigation of the hydrodynamic characteristics of a scale powered dynamic model of a patrol-type seaplane designed by the Glenn L. Martin Company. The seaplane had a high-aspect-ratio wing and a T-tail with an all-movable stabilizer. A comparison was made between two forebody configurations, one with a sharp forebody keel in cross section and the other with the forebody cross section rounded in the vicinity of the keel.
Date: August 17, 1954
Creator: Mottard, Elmo J. & Coffee, Claude W., Jr.
Partner: UNT Libraries Government Documents Department

A Brief Hydrodynamic Investigation of a 1/24-Scale Model of the DR-77 Seaplane

Description: From Summary: "A limited investigation of a 1/24-scale dynamically similar model of the Navy Bureau of Aeronautics DR-77 design was conducted in Langley tank no. 2 to determine the calm-water take-off and the rough-water landing characteristics of the design with particular regard to the take-off resistance and the landing accelerations. During the take-off tests, resistance, trim, and rise were measured and photographs were taken to study spray. During the landing tests, motion-picture records and normal-acceleration records were obtained."
Date: June 4, 1953
Creator: Fisher, Lloyd J. & Hoffman, Edward L.
Partner: UNT Libraries Government Documents Department

A brief investigation of the effect of waves on the take-off resistance of a seaplane

Description: Report presenting testing to determine the resistance of a model of a seaplane with a length-beam ratio of 15 and a wing loading of 120 pounds per square foot was determined in smooth water and three wave heights under various conditions of load, speed, elevator setting, angle of dead rise, and center-of-gravity position.
Date: April 24, 1956
Creator: Mottard, Elmo J.
Partner: UNT Libraries Government Documents Department