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Wheel Brakes and Their Application to Aircraft

Description: "The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls" (p. 1).
Date: May 1928
Creator: Dowty, G. H.
Partner: UNT Libraries Government Documents Department

A Brief Study of the Speed Reduction of Overtaking Airplanes by Means of Air Brakes, Special Report

Description: As an aid to airplane designers interested in providing pursuit airplanes with decelerating devices intended to increase the firing time when overtaking another airplane, formulas are given relating the pertinent distances and speeds in horizontal flight to the drag increase required. Charts are given for a representative parasite-drag coefficient from which the drag increase, the time gained, and the closing distance may be found. The charts are made up for three values of the ratio of the final speed of the pursuing airplane to the speed of the pursued airplane and for several values of the ratio of the speed of the pursued airplane to the initial speed of the pursuing airplane. Charts are also given indicating the drag increases obtainable with double split flaps and with conventional propellers. The use of the charts is illustrated by an example in which it is indicated that either double split flaps or, under certain ideal conditions, reversible propellers should provide the speed reductions required.
Date: May 1942
Creator: Pearson, H. A. & Anderson, R. F.
Partner: UNT Libraries Government Documents Department

The effects of aerodynamic brakes upon the speed characteristics of airplanes

Description: Report presenting a study of the factors influencing the performance of aerodynamic brakes. The increases in drag coefficient that are characteristics of several types of wing and fuselage aerodynamic brakes, which have been tested in wind tunnels or in flight, are summarized in the report.
Date: September 1949
Creator: Stephenson, Jack D.
Partner: UNT Libraries Government Documents Department

A study of the application of data on various types of flap to the design of fighter brakes

Description: Report presenting an approximate method of applying the available data on various types of flaps in the design of fighter brakes together with several examples of its use. The computed effects of flap type, size, location, and deflection as well as the effects of altitude and initial velocities on braking characteristics are also shown in some examples using the method to determine various flap arrangements.
Date: June 1942
Creator: Purser, Paul E.
Partner: UNT Libraries Government Documents Department

The Effects at a Mach Number of 6.86 of Drag Brakes on the Lift, Drag, and Pitching Moment of an Ogive Cylinder

Description: Memorandum presenting results of three-component force tests of a cylindrical body with an ogival nose equipped with panel-type drag brakes each covering approximately 21 percent of the body circumference and located on opposite sides of the body at the rear end. Results regarding the drag brakes in the horizontal plane, drag brakes in the vertical plane, comparison of drag brakes, and minimum drag are provided.
Date: March 19, 1956
Creator: Penland, Jim A. & Fetterman, David E., Jr.
Partner: UNT Libraries Government Documents Department

A New Dynamometer Brake

Description: The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.
Date: September 1921
Creator: Segrè, Marco
Partner: UNT Libraries Government Documents Department

A Variable Speed Fan Dynamometer

Description: Fan brakes used as absorption dynamometers in testing internal combustion engines have the disadvantage that a given fan will run only at one speed when the engine is delivering full power. In order to be able to vary the speed at which a given power will be absorbed, English manufacturers have for some time been using a cylindrical housing around the fan with one or two variable openings in the periphery. Here, results are given of tests conducted to determine how great a range of speed can be obtained from such a device.
Date: December 1920
Creator: Wood, Karl D.
Partner: UNT Libraries Government Documents Department

Experiments With Airplane Brakes

Description: This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading.
Date: September 1931
Creator: Michael, Franz
Partner: UNT Libraries Government Documents Department

DFS Dive-Control Brakes for Gliders and Airplanes and Analytical Study of the Drag of the DFS Dive-Control Brake

Description: These two reports are surveys on the progress and present state of development of dive-control flaps for gliders and airplanes. The second article describes how on the basis of wind tunnel and free-flight tests, the drag increase on brake flaps of the type DFS, can be predicted. Pressure records confirm a two-dimensional load distribution along the brake-flap surface.
Date: January 1940
Creator: Jacobs, Hans & Wanner, Adolf
Partner: UNT Libraries Government Documents Department

An Experimental Investigation of the Thrust and Torque Produced by Propellers Used as Aerodynamic Brakes

Description: Report presenting the results of a wind-tunnel investigation of propellers operating at negative thrust. Negative-thrust characteristics of two- and four-blade single propellers and four- and eight-blade dual propellers were determined. The results indicate that the constant-speed reversed-pitch propellers posses aerodynamic characteristics that should make them excellent aerodynamic brakes.
Date: August 1944
Creator: Hedrick, William S. & Douglass, William M.
Partner: UNT Libraries Government Documents Department

The Use of Wheel Brakes on Airplanes

Description: The results of tests to determine the effect of wheel brakes on the landing run of an airplane under conditions of load and at various wind velocities are presented.
Date: July 1929
Creator: Carroll, Thomas & DeFrance, Smith J.
Partner: UNT Libraries Government Documents Department

An Experimental Investigation of the Effect of Propellers Used as Aerodynamic Brakes on Stability and Control

Description: "Tests were made of a model representative of a single-engine tractor-type airplane for the purpose of determining the stability and control effects of a propeller used as an aerodynamic brake. The tests were made with single-and dual-rotation propellers to show the effect of type of propeller rotation, and with positive thrust to provide basic data with which to compare the effects of negative thrust. Four configurations of the model were used to give the effects of tilting the propeller thrust axis down 5 deg., raising the horizontal tail, and combining both tilt and raised tail" (p. 1).
Date: July 1945
Creator: Stevens, Victor I.; McCullough, George B. & Hanson, Frederick H.
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of a Slot-Lip Aileron and Slotted Flap for Dive Brakes

Description: From Introduction: "As a part of this investigation, a study is being made of test results obtained during the development of devices designed primarily for other purposes, such as high lift or lateral control, but which may also be used for dive control. These results have been reanalyzed and are herein presented in a form that should make them convenient for design purposes."
Date: April 1941
Creator: Rogallo, F. M.
Partner: UNT Libraries Government Documents Department

Speed-Brake Investigation at Low Speed of a 1/10-Scale Model of the MX-1554A Airplane With a Circular Jet Nozzle

Description: Memorandum presenting data from an investigation of the effect of curved speed brakes on the drag characteristics and on the longitudinal stability and control characteristics of a scale model of the MX-1554A airplane redesigned to incorporate a circular jet nozzle. The speed brakes were tested at several deflections,gaps, and locations on the landing configuration and the clean configuration.
Date: January 7, 1954
Creator: Solomon, Martin
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigations of Diving Brakes

Description: Unduly high diving speeds can be effectively controlled by diving brakes but their employment involves at the same time a number of disagreeable features: namely, rotation of zero lift direction, variation of diviving moment, and, the creation of a potent dead air region.
Date: November 1942
Creator: Fuchs, D.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Tests on Various Types of Dive Brakes Mounted in Proximity of the Leading Edge of the Wing

Description: "The present report is concerned with a series of tests on a model airplane fitted with four types of dive flaps of various shapes, positions, and incidence located near the leading edge of the wing (from 5 to 20 percent of the wing chord). Tests were also made on a stub airfoil fitted with a ventral dive (located at 8 percent of the wing chord). The hinge moments of the dive flaps were measured" (p. 1).
Date: May 1949
Creator: Lattanzi, Bernardino & Bellante, Erno
Partner: UNT Libraries Government Documents Department

Tests of a 0.30 scale semispan model of the Douglas XTB2D-1 airplane wing and fuselage combination in the NACA 19-foot pressure tunnel 1: full-span flap and air-brake investigation

Description: Report presenting testing in the 19-foot pressure tunnel of a scale semispan model of the XTB2D-1 airplane wing and fuselage combination. The purpose of the investigation was to determine the optimum position of the double-slotted flap, the characteristics of the full-span flaps at various deflections in their fully extended position, the effectiveness of deflecting the full-span flaps to small positive angles as a camber changing feature, the stalling characteristics of the wing, and the effectiveness of the flap as a brake when deflected to negative angles.
Date: September 1944
Creator: Ashworth, C. Dixon; Spooner, Stanley H. & Russell, Robert T.
Partner: UNT Libraries Government Documents Department

Low-Speed Investigation of the Effects of Wing Tanks and Speed Brakes on the Static Stability of a Model Having a 40 Degree Swept Wing

Description: Memorandum presenting a low-speed wind-tunnel investigation conducted to study the effects of pylon-mounted wing tanks and speed brakes on the static stability characteristics of a model with sweptback wing and tail surfaces. The wing of the model was of aspect ratio 3.45 and was swept 40 degrees at the quarter-chord line. Results for the basic configuration and modifications to the basic configuration are provided.
Date: May 25, 1955
Creator: Sleeman, William C., Jr. & Alford, William J., Jr.
Partner: UNT Libraries Government Documents Department

Frictional behavior of automotive brake materials under wet and dry conditions

Description: The purpose of this effort was to develop an improved understanding of the relationship between the structure and frictional behavior of materials in the disc brake/rotor interface with a view toward improving the performance of automotive disc brakes. The three tasks involved in this Cooperative Research and Development Agreement (CRADA) were as follows: Task 1. Investigation of Brake Pads and Rotors. Characterize surface features of worn brake pads and rotors, with special attention to the transfer film which forms on them during operation. Ford to supply specimens for examination and other supporting information. Task 2. Effects of Atmosphere and Repeated Applications on Brake Material Friction. Conduct pin-on-disk friction tests at ORNL under controlled moisture levels to determine effects of relative humidity on frictional behavior of brake pad and rotor materials. Conduct limited tests on the characteristics of friction under application of repeated contacts. Task 3. Comparison of Dynamometer Tests with Laboratory Friction Tests. Compare ORNL friction data with Ford dynamometer test data to establish the degree to which the simple bench tests can be useful in helping to understand frictional behavior in full-scale brake component tests. This final report summarizes work performed under this CRADA.
Date: December 15, 1996
Creator: Blau, P.J.; Martin, R.L.; Weintraub, M.H.; Jang, Ho & Donlon, W.
Partner: UNT Libraries Government Documents Department

Speed-brake investigation at low speed of a 1/10-scale model of the MX-1554A airplane with a circular jet nozzle

Description: Report discussing an investigation of the effect of curved speed brakes on the drag characteristics and longitudinal stability and control characteristics of a model of the MX-1554A with a circular jet nozzle. The speed brakes were tested at several deflections, gaps, and locations in the landing configuration and clean configuration. Results of a lateral- and directional-stability study due to reduction in the vertical tail area are also provided.
Date: January 7, 1954
Creator: Solomon, Martin
Partner: UNT Libraries Government Documents Department

Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

Description: The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data revealed ...
Date: October 1, 2013
Creator: Lascurain, Mary Beth; Capps, Gary J & Franzese, Oscar
Partner: UNT Libraries Government Documents Department

Wind turbine trailing edge aerodynamic brakes

Description: Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).
Date: April 1, 1995
Creator: Migliore, P G; Miller, L S & Quandt, G A
Partner: UNT Libraries Government Documents Department


Description: The report summarizes what transpired during brake linings-related workshop held at the Fall 2003 meeting of the Technology and Maintenance Council (TMC) in Charlotte, NC. The title of the workshop was ''Developing a Useful Friction Material Rating System''. It was organized by a team consisting of Peter Blau (Oak Ridge National Laboratory), Jim Britell (National Highway Traffic Safety Administration), and Jim Lawrence (Motor and Equipment Manufacturers Association). The workshop was held under the auspices of TMC Task Force S6 (Chassis), chaired by Joseph Stianche (Sanderson Farms, Inc.). Six invited speakers during the morning session provided varied perspectives on testing and rating aftermarket automotive and truck brake linings. They were: James R. Clark, Chief Engineer, Foundation Brakes and Wheel Equipment, Dana Corporation, Spicer Heavy Axle and Brake Division; Charles W. Greening, Jr, President, Greening Test Labs; Tim Duncan, General Manager, Link Testing Services;Dennis J. McNichol, President, Dennis NationaLease; Jim Fajerski, Business Manager, OE Sales and Applications Engineering, Federal Mogul Corporation; and Peter J. Blau, Senior Materials Development Engineer, Oak Ridge National Laboratory. The afternoon break-out sessions addressed nine questions concerning such issues as: ''Should the federal government regulate aftermarket lining quality?''; ''How many operators use RP 628, and if so, what's good or bad about it?''; and ''Would there be any value to you of a vocation-specific rating system?'' The opinions of each discussion group, consisting of 7-9 participants, were reported and consolidated in summary findings on each question. Some questions produced a greater degree of agreement than others. In general, the industry seems eager for more information that would allow those who are responsible for maintaining truck brakes to make better, more informed choices on aftermarket linings. A written fleet operator survey was also conducted during the TMC meeting. Twenty-one responses were received, spanning fleet sizes between 12 and 170,000 ...
Date: February 3, 2003
Creator: Blau, P.J.
Partner: UNT Libraries Government Documents Department