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Some Ideas on Racing Seaplanes

Description: This report presents the author's designs and construction of various seaplanes to raced in the Schneider Cup. The results of tests are presented as well as discussions of various structures like floats and wings.
Date: November 1932
Creator: Pegna, Giovanni
Partner: UNT Libraries Government Documents Department

The Simplifying Assumptions, Reducing the Strict Application of Classical Hydrodynamics to Practical Aeronautical Computations

Description: Note presenting a general method followed to simplify the numerical work in hydrodynamics, which consists of neglecting quantities of a lower order of magnitude. Four of the solutions covered in this report include the theory of the lateral air forces on airship hulls, theory of wing sections in a two-dimensional flow, theory of wings with a finite span, and propeller theory.
Date: November 1924
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department

Effect of Increase in Angle of Dead Rise on the Hydrodynamic Qualities of a Seaplane Configuration Incorporating High Wing Loading

Description: Memorandum presenting an investigation to determine the effects of increase in angle of dead rise on the overall hydrodynamic characteristics of a seaplane having a length-beam ratio of 15 and a wing loading of 120 pounds per square foot. In general, increasing the angle of dead rise from 20 to 40 degrees and 60 degrees improved the trim limits of stability and the range of center-of-gravity positions for satisfactory take-off characteristics.
Date: October 31, 1956
Creator: Kapryan, Walter J. & Weinstein, Irving
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

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

Effects of sweepback and taper on the force and cavitation characteristics of aspect-ratio-4 hydrofoils

Description: Report presenting an investigation to determine the effects of sweepback and taper ratio on the cavitation and hydrodynamic force characteristics of hydrofoils. Four hydrofoils were used, all of which had different taper ratios and degrees of sweep. Results regarding the effect of cavitation on hydrodynamic characteristics, effect of sweep on cavitation and force characteristics, effect of taper ratio on cavitation and force characteristics, and a comparison with wind-tunnel data are provided.
Date: December 2, 1952
Creator: King, Douglas A. & Land, Norman S.
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

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

A Résumé of the Advances in Theoretical Aeronautics Made by Max M. Munk

Description: "In order to apply profitably the mathematical methods of hydrodynamics to aeronautical problems, it is necessary to make simplifications in the physical conditions of the latter. In a valuable paper presented by Dr. Max M. Munk, of the National Advisory Committee for Aeronautics, Washington, to the Delft Conference in April, 1924, these necessary simplifying assumptions are discussed in detail. It is the purpose of the present paper to present in as simple a manner as possible some of the interesting results obtained by Dr. Munk's methods" (p. 93).
Date: 1926
Creator: Ames, Joseph S.
Partner: UNT Libraries Government Documents Department

Hydrodynamic Characteristics of a Model of a Proposed Six-Engine Hull-Type Seaplane Designed for Supersonic Flight

Description: Memorandum presenting an investigation of the hydrodynamic characteristics of a six-engine hull-type seaplane designed for supersonic flight. The configuration had four engines mounted on top of the wing in individual nacelles and two engines mounted on top of the aft section of the hull with their inlets located on top of the wing.
Date: July 14, 1958
Creator: Coffee, Claude W., Jr.
Partner: UNT Libraries Government Documents Department

Hydrodynamic Characteristics of Missiles Launched Under Water

Description: Report presenting some of the hydrodynamic problems associated with launching an air missile from underwater. The results of an experiment with models are also provided, including deviation angle, effect of forward speed of the submarine, curved path of the missile, and potential environmental disruptions.
Date: June 27, 1958
Creator: Dawson, John R.
Partner: UNT Libraries Government Documents Department

Preliminary Tests in the NACA Tank to Investigate the Fundamental Characteristics of Hydrofoils

Description: A preliminary investigation made to study the hydrodynamic properties and general behavior of simple hydrofoils. Six plain, rectangular hydrofoils were tested in a tank at various speeds, angles of attack, and depths below the water surface. The results are presented as curves of the lift and drag coefficients plotted against speed for various angles of attack and depths for which the hydrofoils were tested.
Date: September 1940
Creator: Ward, Kenneth E. & Land, Norman S.
Partner: UNT Libraries Government Documents Department

Preliminary tank tests of an outboard float having the form of a streamline body of revolution fitted with a hydrofoil

Description: Report presenting preliminary tests in tank no. 1 to investigate the hydrodynamic qualities of a streamline body of revolution of a fineness ratio of 5.14 with and without a lifting hydrofoil. Results regarding interference, incidence, spray, trimming moment, comparison with a conventional float, and aerodynamic drag are provided.
Date: April 1944
Creator: King, Douglas A.
Partner: UNT Libraries Government Documents Department

Application of Practical Hydrodynamics to Airship Design

Description: The purpose of the first two parts of this report is to present in concise format all the formulas required for computation of the hydrodynamic forces, so that they can be easily computed for either straight or curvilinear flight. Improved approximations are also introduced having a high degree of accuracy throughout the entire range of practical proportions. The remaining two parts of the report are devoted respectively to stability and skin friction, as functions of the same hydrodynamic forces.
Date: 1933
Creator: Upson, Ralph H. & Klikoff, W. A.
Partner: UNT Libraries Government Documents Department

Propagation of Density Disturbances in Air-Water Flow

Description: From Introduction: "In this work, a forced-circulation air-water loop was employed for investigating the behavior of void perturbations. Upon attaining steady-state conditions, disturbances in the void fraction were superimposed at very low frequencies (~0.4 cps). A better understanding of hydrodynamic transient behavior will generate more confidence in the design of boiling-water reactor systems."
Date: June 1965
Creator: Nassos, George P.
Partner: UNT Libraries Government Documents Department

Similitude in Hydrodynamic Tests Involving Planing

Description: The problems of using models in planing tests are addressed. If one passes from the model to a hull of linear dimensions n times greater, the speeds are connected by the law of mechanical similitude. The normal forces given by the hydrodynamic equations (perfect fluid) also follow the law of dynamic similitude (Reech's method) and are multiplied by n(exp 3). A series of tests were performed and the actual results were compared to theoretical results.
Date: May 1936
Creator: Gruson, M. F.
Partner: UNT Libraries Government Documents Department

Tests of the Landing on Water of a Model of a High-Speed Airplane - Langley Tank Model 229

Description: Memorandum presenting an investigation at the tank no. 2 monorail of the landing on smooth water of a scale model of a hypothetical jet- and rocket-propelled airplane designed to fly at transonic speeds. The test is part of an investigation of the feasibility of the operation from water of high-speed airplanes. The results of the test form a basis for evaluating the improvement in hydrodynamic characteristics.
Date: December 9, 1947
Creator: King, Douglas A.
Partner: UNT Libraries Government Documents Department

A Theoretical Investigation of the Effect of Partial Wing Lift of Hydrodynamic Landing Characteristics of V-Bottom Seaplanes in Step Impacts

Description: A theoretical investigation is made of the loads and motions in water-landing impacts of wide prismatic V-bottom seaplanes for constant partial wing-lift conditions where the resultant velocity of the seaplane is normal to the keel. An approximate method is given for applying the results of this investigation to the more general case of oblique impact. The increase in vertical hydrodynamic load factor due to wing-lift reduction is shown to be approximately 133 percent of the decrease in air load.
Date: November 1952
Creator: Sims, Joseph L. & Schnitzer, Emanuel
Partner: UNT Libraries Government Documents Department

The Transference of Heat From a Hot Plate to an Air Stream

Description: The object of the present study was to define experimentally the field of temperature and velocity in a heated flat plate when exposed to an air stream whose direction is parallel to it, then calculate therefrom the heat transference and the friction past the flat plate, and lastly, compare the test data with the mathematical theory. To ensure comparable results, we were to actually obtain or else approximate: a) two-dimensional flow; b) constant plate temperature in the direction of the stream. To approximate the flow in two dimensions, we chose a relatively wide plate and measured the velocity and temperature in the median plane.
Date: April 1931
Creator: Elias, Franz
Partner: UNT Libraries Government Documents Department

Investigations and Tests in the Towing Basin at Guidonia

Description: The experimental methods at the Guidonia towing basin are discussed including specifications. Some of the components examined are the bridge towing carriage, side towing carriage, catapult installation, and dynamometer systems. Tests were performed on hulls and floats, as well as motor boats and torpedo shaped bodies. Theoretical investigations were also performed to determine pressure distributions on geometrically simple bodies, propagation of small wave motions, and planing and submerged surfaces.
Date: April 1939
Creator: Cremona, C.
Partner: UNT Libraries Government Documents Department

Impact-Loads Investigation of Chine-Immersed Models Having Concave-Convex Transverse Shape and Straight or Curved Keel Lines

Description: Note presenting an investigation of three narrow-beam models of concave-convex transverse shape and having, respectively, a straight keel, a curved bow, and a curved stern tested at the Langley impact basin as part of a larger study of hydrodynamic impact loads on chine-immersed bodies of heavy beam loading. Testing occurred over a wide range of trim and initial-flight-path angles. Results regarding the transverse curvature, longitudinal curvature, rough water, and observations on the constant-force-type bottom.
Date: February 1957
Creator: Edge, Philip M., Jr.
Partner: UNT Libraries Government Documents Department