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Results for “FLOATS AND HULLS - DESIGN”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1936

The impact on floats or hulls during landing as affected by bottom width

For floats and hulls having V bottoms the impact force does not necessarily increase with increasing width. Therefore, the weight of the float landing gear, side walls, and other parts, and of the fuselage construction need not be increased with increasing bottom width, but the weight of the bottom construction itself, on the other hand, does not increase with increase in bottom width and is largely determined by the type of construction.

Mewes, E↗
NASA NTRS1927

Tests on airplane fuselages, floats and hulls

This report is a compilation of test data on airplane fuselages, nacelles, airship cars, seaplane floats, and seaplane hulls, prepared by the Bureau of Aeronautics, at the requests of the National Advisory Committee for Aeronautics. The discussion of the data includes the derivation of a scale correction curve to be used in obtaining the full scale drag. Composite curves of drag and L/D for floats and hulls are also given. (author)

Diehl, Walter S↗
NASA NTRS1924

Static stability of seaplane floats and hulls

Values of lateral and longitudinal metacentric heights for various seaplanes were calculated by means of approximate formulae derived here. The data are given in tabular form. Upon plotting these metacentric heights against the corresponding gross weights, it appears that the metacentric height is approximately a straight line function of the gross weight. For the lateral metacentric height GM = 13 + .002 W and for longitudinal metacentric height GM = 15 + .002 W, GM is in feet and the gross weight (W) is in pounds. Although only approximate, it is thought that the values indicated here are a reliable guide to current practice. It is recommended that the longitudinal and lateral metacentric heights be made equal and of the value given by GM = 15 = .002 W. The proper length or spacing required to satisfy the indicated value may then be obtained from substitution in the approximate formulae for metacentric height.

Diehl, W S↗
NASA NTRS1930

Water Pressure Distribution on a Twin-Float Seaplane

This is the second of a series of investigations to determine water pressure distribution on various types of seaplane floats and hulls, and was conducted on a twin-float seaplane. It consisted of measuring water pressures and accelerations on a TS-1 seaplane during numerous landing and taxiing maneuvers at various speeds and angles. The results show that water pressures as great as 10 lbs. per sq. in.may occur at the step in various maneuvers and that pressures of approximately the same magnitude occur at the stern and near the bow in hard pancake landings with the stern way down. At the other parts of the float the pressures are less and are usually zero or slightly negative for some distance abaft the step. A maximum negative pressure of 0.87 lb. Per square inch was measured immediately abaft the step. The maximum positive pressures have a duration of approximately one-twentieth to one-hundredth second at any given location and are distributed over a very limited area at any particular instant.

Thompson, F L↗
NASA NTRS1931

Water Pressure Distribution on a Flying Boat Hull

This is the third in a series of investigations of the water pressures on seaplane floats and hulls, and completes the present program. It consisted of determining the water pressures and accelerations on a Curtiss H-16 flying boat during landing and taxiing maneuvers in smooth and rough water.

Thompson, F L↗
NASA NTRS1935

Hydrodynamic Tests of Models of Seaplane Floats

This report contains the results of tank tests carried out at free trim on seventeen hulls and floats of various types. The data as to the weight on water, trim, and relative resistance for each model are plotted nondimensionally and are referenced both to the total weight and to the weight on water. Despite the fact that the experiments were not made systematically, a study of the models and of the test data permits nevertheless some general deductions regarding the forms of floats and their resistance. One specific conclusion is that the best models have a maximum relative resistance not exceeding 20 percent of the total weight.

Eula, Antonio↗
NASA NTRS1938

The Aerodynamic Drag of Five Models of Side Floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

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.

House, R O↗
NASA NTRS1929

Force measurements on airplanes

The most essential phenomena of aircraft should be classified according to their origin and then measured. Information can thus be obtained in a quicker, cheaper, and more reliable way than otherwise would be possible.

HUB DYNAMOMETERS, ETC↗
NASA NTRS1947

A Theoretical Investigation of Hydrodynamic Impact Loads on Scalloped-Bottom Seaplanes and Comparisons with Experiment

An analytical method is presented for calculating the hydrodynamic impact loads and motions experienced by seaplane floats and hulls with scalloped (fluted) bottoms. The analysis treats vertical impact at zero trim in addition to the more general problem of the step impact of a seaplane at positive trim where the flight path is oblique to the keel and to the water surface. Also considered are the transformations required to represent impacts into waves.

Milwitzky, Benjamin↗
NASA NTRS1952

Generalized theory for seaplane impact

The motions, hydrodynamic loads, and pitching moments experienced by v-bottom seaplanes during step-landing impacts are analyzed and the theoretical results are compared with experimental data. In the analysis, the primary flow about the immersed portion of a keeled hull or float is considered to occur in transverse flow planes and the concept of virtual mass is applied to determined the reaction of the water to the motions of the seaplane. The entire immersion process is analyzed from the instant of initial contact until the seaplane rebounds from the water surfaces. The analysis is applicable to the complete range of initial contact conditions between the case of impacts where the resultant velocity is normal to the keel and the limiting condition of planing.

Milwitzky, Benjamin↗
NASA NTRS1939

Investigations and Tests in the Towing Basin at Guidonia

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.

Cremona, C↗
DOE OSTI2026

FOCAL Campaign IV: Integrated System Control: Turbine + Hull

Campaign IV of the Floating Offshore-wind Controls Advanced Laboratory Experimental Program (FOCAL) aimed to generate a dataset enabling the validation of a floating offshore wind turbine with turbine and hull controls. The turbine considered in this campaign is the scaled IEA 15MW Reference Wind Turbine similar to the setup considered in FOCAL Campaign I. This turbine is mounted on the VolturnUS platform with integrated hull controls similar to the hull considered in FOCAL Campaign II/III. This system is deployed for a fully-coupled wind and wave testing campaign at the University of Maine's Harold Alfond Wind and Wave (W2) facility. System dynamics and turbine characteristics are measured to determine global performance and assess the effect of the control strategies employed. NREL's reference open-source controller (ROSCO) is used for active blade pitch control and hull structural control is examined through the use of tuned mass dampers (TMD's) tuned to the systems pitch and tower-bending natural frequency. The naming convention of the load cases considered are described in the data details section. Detailed properties on the modeled system are found in the following reference: Lenfest E., Floating Offshore-wind Controls Advanced Laboratory (FOCAL) Experimental Program - Campaign IV: 1:70 Model-scale Testing of the IEA-Wind 15MW Reference Turbine and the VolturnUS-S Platform. UMaine ASCC Report Number 23-57-1183.

17 WIND ENERGY↗
NASA NTRS1942

Normal-pressure Tests of Circular Plates with Clamped Edges

A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness from 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of permanent set as a function of the dimensions of the plate and the tensile properties of the material.

CIRCULAR↗
NASA NTRS1927

Richard-Penhoet commercial seaplane

This is a multi-engine monoplane with a central hull and without external bracing. The trim of the seaplane on the water is assured by two wing floats, one on each side of the hull 9 m. from its axis. It has a total power of 2100 HP. from 5 air cooled Jupiter radial engines.

RICHARD-PENHOET SEAPLANES (FR )↗