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Comparative Tests of Run-of-Mine and Briquetted Coal on the Torpedo Boat Biddle

Description: From Introduction: "With the particular equipment used in the tests both coal and briquets were far from smokeless; consequently the data of this bulletin are applicable only by analogy to parallel operation with a coal more nearly smokeless, but nevertheless applicable with much reliability. It was the original intention to make a set of preliminary steaming tests alongside a dock (which tests furnish material for this bulletin) an to finish with a set of running tests at sea; but the running tests were never made. for lack of time and men."
Date: 1911
Creator: Ray, Walter T. & Kreisinger, Henry
Partner: UNT Libraries Government Documents Department

Landing Characteristics in Waves of Three Dynamic Models of Flying Boats

Description: Powered models of three different flying boats were landed in oncoming wave of various heights and lengths. The resulting motions and acceleration were recorded to survey the effects of varying the trim at landing, the deceleration after landing, and the size of the waves. One of the models had an unusually long afterbody. The data for landing with normal rates of deceleration indicated that the most severe motions and accelerations were likely to occur at some period of the landing run subsequent to the initial impact.
Date: May 7, 1947
Creator: Benson, James M.; Havens, Robert F. & Woodward, David R.
Partner: UNT Libraries Government Documents Department

Rough-water Landings of a 0.1-Size Powered Dynamic Model of the XP5Y-1 Flying Boat with Two Types of Afterbody - Langley Tank Model 228 (TED No. NACA DE309)

Description: A 0.1-size powered dynamic model of a large, high-speed flying boat was landed in Langley tank no. 1 into oncoming waves 4 feet high (full size). The model was tested with two afterbodies of differing lengths (4.12 and 6.63 beams). The short afterbody had a constant angle of dead rise of 22.5deg and a keel angle of 6.5deg. The long afterbody had warped dead rise and a keel angle of 8.5deg. The vertical accelerations were slightly greater and the maximum angular accelerations and maxim= trims were slightly less for the model with the long afterbody than for the model with -the short afterbody. A wave length of 210 feet (full size) imposed the highest accelerations on the model with either the long or the short afterbody.
Date: February 9, 1949
Creator: Garrison, Charlie C.
Partner: UNT Libraries Government Documents Department

Landing characteristics in waves of three dynamic models of flying boats

Description: Powered models of three different flying boats were landed in oncoming waves of various heights and lengths. The effects of varying the trim at landing, the deceleration after landing, and the size of the waves were determined. Data are presented on the motions and accelerations obtained during landings in rough water.
Date: January 1952
Creator: Benson, James M.; Havens, Robert F. & Woodward, David R.
Partner: UNT Libraries Government Documents Department

Landing characteristics of a model of a flying boat with the depth of step reduced to zero by means of a retractable planing flap

Description: From Conclusion: "A model of a flying boat was tested to determine the landing characteristics when the depth of the step was reduced to zero by means of a retractable planing flap on the forebody." The results of stability and resistance testing are presented.
Date: February 1944
Creator: Benson, James M. & Freihofner, Anton
Partner: UNT Libraries Government Documents Department

The landing stability of a powered dynamic model of a flying boat with a 30 degree v-step and with two depths of transverse step

Description: Report discusses tests conducted using a model of a four-engine long-range flying boat with a 30 degree V-step and two different transverse steps of comparable positions and depths. The limits of stability, landing speed, and landing characteristics of the different models are presented.
Date: February 1944
Creator: Parkinson, John B. & Land, Norman S.
Partner: UNT Libraries Government Documents Department

On the theory of unsteady planing and the motion of a wing with vortex separation

Description: The disturbance imparted to water by a planing body give rise to a wave form of motion on the free surface, the length of the waves increasing indefinitely with increase in the Froude number and being directly proportional to the latter in the case of the plane or two-dimensional problem. At large Froude numbers the effect of the weight shows up to any appreciable extent only at some distance from the body, so that the flow near the body can be considered as part of a flow of an infinitely extending weightless fluid. This paper is a consideration of these characteristics as well as a formulation of the planing problem and its relation to the problem of a thin wing.
Date: May 1940
Creator: Sedov, L.
Partner: UNT Libraries Government Documents Department

The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

Description: Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to determine piloting technique for optimum take-off.
Date: April 29, 1940
Creator: Olson, R. E. & Allison, J. M.
Partner: UNT Libraries Government Documents Department

The aerodynamic drag of flying-boat hull model as measured in the NACA 20-foot wind tunnel - I

Description: From Introduction: "The main purpose of this investigation is to make available to the designer useful information with regard to the aerodynamic drag of various types of flying-boat hull models. The present report is the first in a series covering investigation in this field. Through close cooperation between hydrodynamics and aerodynamics divisions it is hoped that results leading to improvements in hull design obtained."
Date: April 1935
Creator: Hartman, Edwin P.
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

Resistance tests of models of three flying-boat hulls with a length-beam ratio of 10.5

Description: Report presenting testing of models of three flying-boat hulls with a length-beam ratio of 10.5. Testing occurred at two depths of step and two angles of dead rise. Results regarding resistance, trimming-moment, and wetted-length data for general fixed-trim and free-to-trim tests at load coefficients up to 4.0 are provided.
Date: September 1945
Creator: Bidwell, Jerold M. & Goldenbaum, David M.
Partner: UNT Libraries Government Documents Department

Rough-Water Tests of Models of the Vosper and Plum Planing Boats

Description: Models of two types of high-speed surface craft were tested in Langley tank no. 1 to obtain rough-water data for an evaluation by the David Taylor .Model Basin of the relative merits of the designs. Time-history records were obtained of trim, rise, and normal acceleration at two points in the hulls for various speeds and two sizes of waves.
Date: April 27, 1950
Creator: Chambliss, Derrill B. & Blanchard, Ulysse J.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a flying-boat hull having a length-beam ratio of 15 and a warped forebody

Description: From Introduction: "The results of two phases of this investigation, presented in references 1 and 2, have indicated possible ways of reducing hull drag without causing large changes in aerodynamic stability and hydrodynamic performance."
Date: February 11, 1949
Creator: MacLeod, Richard G.
Partner: UNT Libraries Government Documents Department

General free to trim tests in NACA tank no.2 of three 1/8-full-size models of flying-boat hulls at low speeds-NACA models 116E-3K, 120R, and 143

Description: Report presenting tests of representative models of flying boat hulls to determine the resistance at low speeds. Results regarding the effect of load coefficients, resistance coefficients, and towing and drifting calculations are provided.
Date: January 1943
Creator: Carter, Arthur W.
Partner: UNT Libraries Government Documents Department

An analysis of the airspeeds and normal accelerations of Sikorsky S-42A airplanes in commercial transport operation

Description: From Introduction: "This paper gives the results of an analysis of V-G data taken on four Sikorsky S-42A flying boats operated on Caribbean routes and along the east coast of South America during the period from 1936 to 1939. The available S-42A data are summarized and flight-load results are compared with the results of analyses made in the past."
Date: October 1948
Creator: Walker, Walter G.
Partner: UNT Libraries Government Documents Department

A study of flying-boat take-off

Description: It is shown that the normal resistance curve for a flying boat may be approximated by two straight lines. The equations for take-off distance and time, derived from this approximation, are applied to a series of flying boats and the resulting factors are plotted in non dimensional form in a series of charts. Take-off performances from the charts are shown to be in good agreement with step-by-step integrations. Some applications of the charts to the solution of general design problems are included.
Date: April 1938
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department

A new method of studying the flow of the water along the bottom of a model of a flying-boat hull

Description: A new method of studying the flow of the water along the bottom of a model of a flying-boat hull is described. In this method, the model is fitted with a transparent bottom and is divided down the center line by a bulkhead. The flow is observed and photographed through one-half of the model by means of the diffused illumination from a battery of lamps contained in the other half of the model. Photographs of the flow, particularly of the changes that occur when the step ventilates, are shown. The results of the present investigation indicate that the method has considerable promise, chiefly in connection with motion-picture studies.
Date: February 1940
Creator: Ward, Kenneth E.
Partner: UNT Libraries Government Documents Department

The design of the optimum hull for a large long-range flying boat

Description: Report presenting some principles for designing the optimum hull for a large long-range flying boat in order to suit the requirements of minimum drag, seaworthiness, and ability to take off and land at all operational gross weights. The principles include the use of moderate gross-load coefficients, ample forebody lengths, and deep steps and the close adherence of the form to that of a streamline body of revolution with a moderate fineness ratio.
Date: September 1944
Creator: Parkinson, John B.
Partner: UNT Libraries Government Documents Department

Tests of a dynamic model in NACA tank number 1 to determine the effect of length of afterbody, angle of afterbody keel, gross load, and a pointed step on landing and planning stability

Description: Report presenting testing in tank no. 1 to determine the effect of length of afterbody, angle of afterbody keel, and gross load on the limits of stable trims and landing characteristics of a model of a flying boat with conventional steps. The studies were made with four lengths of afterbody, four angles of afterbody keel, and five gross loads. Results regarding the trim limits of stability and landing stability are provided.
Date: March 1943
Creator: Land, Norman S. & Lina, Lindsay J.
Partner: UNT Libraries Government Documents Department

Piloting of flying boats with special reference to porpoising and skipping

Description: From Summary: "The various types of hydrodynamic instability - including porpoising, skipping, and yawing - that may be encountered during take-off or landing of a flying boat are described and the piloting technique required for efficient take-offs and landings is discussed. Suggestions are made for assisting a pilot to become familiar with the take-off and landing qualities of a flying boat that is new to him."
Date: February 1944
Creator: Benson, James M.
Partner: UNT Libraries Government Documents Department

Hydrodynamic qualities of a hypothetical flying boat with a low-drag hull having a length-beam ratio of 15

Description: Report presenting an investigation of the hydrodynamic qualities of a hypothetical flying boat with a hull with a length-beam ratio of 15 in tank no. 1. The flying boat had a design gross weight of 75,000 pounds, a gross load coefficient of 5.88, a wing loading of 41.1 pounds per square foot, and a power loading of 11.5 pounds per brake horsepower for take-off. Results regarding the longitudinal stability, spray characteristics, take-off performance, and summary chart are provided.
Date: April 1948
Creator: Carter, Arthur W. & Haar, Marvin I.
Partner: UNT Libraries Government Documents Department

The effect of afterbody length of the hydrodynamic stability of a dynamic model of a flying boat: Langley tank model 134

Description: Report presenting some model tests that will be used to guide the relation of length of afterbody and depth of step. Results indicated that an increase in length of afterbody requires an accompanying increase in depth of step to maintain adequate landing stability.
Date: October 1945
Creator: Land, Norman S.
Partner: UNT Libraries Government Documents Department