Criteria

Text:
Display:

Results

Viewing 169981 to 170010 of 185270
1963-01-01
Technical Paper
630488
G.R. Dunton, H.J. Scheule, J.D. Rogers
The introduction of more volatile gasolines to provide good cold-starting and warm-up characteristics brought with it the introduction of problems not previously encountered. This paper deals with the effect of such variables as fuel volatility, air temperature, and humidity, which were studied under carefully controlled conditions. All tests were conducted in the laboratory, since only in this way could precise control of temperature and humidity be accomplished.
1963-01-01
Technical Paper
630489
Alden J. Pahnke
1963-01-01
Technical Paper
630490
T. O. Wagner, J. W. Gorman
Abstract Well-designed experimental programs yield results with broader applicability and better precision at less cost than poorly designed ones. Although every experimental program is “designed” to some extent, knowledge of certain formalized techniques aid the experimenter in developing really good designs. Complete understanding of them is formidable and can be attained only by a specialist. However, the basic ideas are simple and can be grasped by any experimenter. This paper serves as an introduction to: 1. Scope of experimentation. 2. Factorial plans. 3. Lattice plans 4. Fractional replication. 5. Error hierarchy. 6. Analysis of variance. 7. 7. Precision of inferences. With understanding of these basic ideas, augmented by some reading on details, any experimenter can design good programs of moderate scope. He also can recognize cases for which he should obtain help of a specialist, and his greater knowledge will enable him to use this help more advantageously.
1963-01-01
Technical Paper
630485
Henry T. C. Yu
Two principal aspects of fuel distribution in multicylinder engines have been investigated; namely, time variation (cycle-to-cycle) of air-fuel ratio in a given cylinder and geometric variation (cylinder-to-cylinder) of air-fuel ratio in different cylinders. To study the time variation problem, a new technique capable of measuring the air-fuel ratio for individual engine explosions has been developed. An analytical study has provided a correlation between power loss and fuel economy loss with the statistical variance of geometric distribution. To determine the possible cause of geometric maldistribution, a series of experiments using a gaseous fuel to simulate complete vaporization was conducted. The effects of various means of mixing the fuel and air on geometric distribution are discussed.
1963-01-01
Technical Paper
630484
C. M. Mears, R. L. Peterson
Nondimensional parameters are developed and plotted for use in rapid analysis of soft-landing system concepts. With the aid of these charts, optimum soft-landing systems are discussed. The systems automatically control and reduce vehicle energy remaining after main-stage retro-thrust to zero at the landing surface, with an expenditure of a mininum amount of stored energy. Mechanizations of some practical automatic landing systems are presented and compared with an optimum system in terms of energy consumption and ability to tolerate wide ranges of initial vehicle velocities and positions.
1963-01-01
Technical Paper
630487
Shelley Curry
The combustion process in a spark ignition engine has been investigated in terms of flame development and subsequent propagation throughout the combustion chamber. Multiple ionization gaps coupled with advanced electronic instrumentation were used to detect progression of the flame in three dimensions. New information concerning knocking combustion has shown that there is no need to postulate any discontinuity in the rate of the combustion process to explain the occurrence of knock.
1963-01-01
Technical Paper
630486
James D. Symons
Discussion of research program undertaken to study oil seals. The author is chiefly concerned with seal leakage which covers equipment and procedure for performance tests and its causes. The paper also includes a complete revision of SAB J110 which covers equipment and procedure for performance tests on radial lip type seals for rotating shafts.
1963-01-01
Technical Paper
630151
P. E. Pfeifer, W. J. Braun
A process is described for irradiating a cylinder liner so as to concentrate Fe-59 radioactivity (and a smaller amount of Mn-54) in the upper portion of the cylinder, providing a means of testing ring and cylinder wear by radioactive methods. Field test results show that wear at the upper limit of ring travel accounts for about 60% of cylinder wear. Laboratory experiments indicate that ring and cylinder wear relationship is affected by varying operating conditions. Possible anomalies in the ring and cylinder wear relationship warrant further investigation, and the radioactive technique presented here simplifies and expedites such study.
1963-01-01
Technical Paper
630148
George D. Ebersole, P. S. Myers, O. A. Uyehara
The ratio of two temperature gradients across the combustion-chamber wall in a diesel engine is used to provide a heat flow ratio showing the radiant heat transfer as a per cent of local total heat transfer. The temperature gradients were obtained with a thermocouple junction on each side of the combustion-chamber wall. The first temperature gradient was obtained by covering the thermocouple at the cylinder gas-wall interface with a thin sapphire window, while the second was obtained without the window. Results show that the time-average radiant heat transfer is of significant magnitude in a diesel engine, and is probably even more significant in heat transfer during combustion and expansion.
1963-01-01
Technical Paper
630149
John K. Adadevoh, O. A. Uyehara, P. S. Myers
Life histories of droplets evaporating on a hot plate under pressure were obtained. The curves are similar to those obtained by one investigator at atmospheric pressure but are displaced to higher temperatures at higher pressures. Similarities between boiling heat transfer and the life history curves are pointed out. Also, that the liquid will most probably reach critical pressure and temperature at temperatures existing inside an engine. The effects of reaching the critical temperature on heat transfer and on vaporization and diffusion are discussed.
1963-01-01
Technical Paper
630152
George Fisher
The difficulties of maintaining efficient diesel engine performance at 0 F and below are discussed. Problems of cold starting, such as fuel requirements, starting aids, and application of heat are developed. Establishment of a winterizing procedure is needed for adequate diesel operation. Engine cooling systems could be equipped with shutters with thermo controls to prevent heat loss. Properly designed shrouds around the radiator will maintain warmth and improve fan and shutter efficiency. Also, air induction and fuel systems and batteries have to be adapted to maintain efficient zero weather operation.
1963-01-01
Technical Paper
630155
Frank P. Plovick
Semiconductors (diodes and transistors) are contributing considerably toward minimizing operational problems in today's automotive electrical systems. However, because of their polarity-sensitive characteristic, maintenance personnel need to know more about the procedures involved in servicing the various components. This paper discusses diode-rectified generators, their companion regulators, charging system circuitry, and testing procedures involved. Included is an explanation on the differences between the d-c and a-c systems, maintenance checks common to both, basic information pertaining to on-the-vehicle testing, and a general outline covering the individual testing procedures.
1963-01-01
Technical Paper
630153
C. T. Newton
Operation in cold weather of automotive equipment is accomplished successfully if equipment, lubricants and accessories are made to the correct specifications or are adapted to the operating conditions. All components should be ordered to specification and the onus to supply be left to the manufacturer who has the necessary apparatus to test and guarantee their performance. Personnel should be specially trained before attempting to operate vehicles at subzero temperatures.
1963-01-01
Technical Paper
630172
Bruce D. Van Deusen, Alfred D. Bosley
A technique is discussed whereby vehicle vibration problems can be defined and analyzed using a random vibration input, and analyzing the output statistically. The input consists of a random “white noise” input signal to electromechanical shakers which drive the wheel spindles of an actual automobile. The output analysis is of two types. In the one, vibration instrumentation signals are analyzed with an analog computer to yield a direct measurement of the vehicle transfer function. In the second, subjective impressions are analyzed of vibration sensation experienced by passengers within the vehicle. This approach has the advantage of a controlled laboratory experiment in which suspension and structural changes can be analyzed as to their effect on vehicle vibration. It also allows a comparison of subjective impressions with physical measurements.
1963-01-01
Technical Paper
630245
Harold Switzky
The design of hot compression structures is complicated by the various possible stress-strain relationships and structural configurations. A nondimensional design technique is presented in terms of geometric and material parameters that can be evaluated readily from known boundary conditions, type of construction, and stress-strain data. The design procedure for minimum weight is demonstrated for a heated trusslike spar.
1963-01-01
Technical Paper
630251
W. J. Lewis, G. E. Faulkner, D. C. Martin
Information related to the welding of thick titanium alloy plate for submarine hull applications is presented in this paper. The weldability of titanium alloy, welding procedures, and mechanical properties of welded joints are discussed. Welding operations are expected to present the greatest problems in fabricating titanium submarine hulls. Cutting, machining, and forming are not expected to cause major problems, but they will be more difficult to perform on titanium than on the low alloy steels now used in submarine hulls.
1963-01-01
Technical Paper
630249
Donald E. Clark
This paper is tutorial in nature, based mainly on the author’s own experience in electromagnetic interference control. Suggestions are offered for overcoming the effects of extreme environments as they influence interference control techniques. The techniques explained pertain to gasketing, connectors, shielding braid, shielding materials, and filters. The development of a high temperature feed-thru capacitor with solid impregnation capable of withstanding temperatures to 400 F and the environmental conditions of specification MIL-E-5009B is explained.
1963-01-01
Technical Paper
630248
C. E. Shappell
This paper presents a short discussion of lesser known air-craft electrical interference problem areas and their causes. Each problem area is illustrated with a typical example that has caused trouble on Boeing transports. Also, the size and complexity of electrical interference possibilities on modern transport type aircraft are briefly discussed.
1963-01-01
Technical Paper
630238
Joseph M. Palsulich
High energy rate forging is an outstanding development in metalworking technology. Many advantages over conventional metalworking processes are offered by this new method. Controlled energy and high rates of billet deformation set this process apart from all others. The benefits derived from this controlled energy and high rate of deformation are numerous, as this paper shows.
1963-01-01
Technical Paper
630236
Commander Henry Bress
This is an up-to-date report on the Navy’s problems resulting from radio frequency interference. The Navy’s approach is to preclude or minimize the interference problem by proper system design during research and development, by proper frequency management, and by engineered installations. The term “radio frequency compatibility” as used is defined. The background and evolution of the radio frequency interference problem is explained. Shipboard interference problem areas coupled with command responsibility are set forth with interesting examples.
1963-01-01
Technical Paper
630242
J. M. Bridges
This paper emphasizes the need for all people concerned in the design and operation of electronic military devices to recognize and take into account the existence of problems in electromagnetic compatibility. The Electromagnetic Compatibility Program of the Dept. of Defense is described, and numerous interdependent aspects of the program that require careful management attention are touched upon.
1963-01-01
Technical Paper
630261
D. O. HItzman, J. A. Shotton, H. E. Alquist
SUMMARY PFA 55MB, the jet fuel anti-icing additive now in general U.S. military service use, has demonstrated biocidal effectiveness in service and in the laboratory on microbial growths representative of those known to exist in the field. The recent announcement of this effect by Phillips Petroleum Company, which developed and patented the product, has aroused interest in military and commercial aviation circles in the U. S. and abroad, partly because of the significance of the finding itself, but also because this product has already been tested, found compatible with materials of aircraft construction and approved for military use (specification MIL-I-27686A) and, by the FAA, for commercial use. Its biocidal feature can therefore be immediately utilized in service without further testing. This paper is concerned solely with the biocidal feature of PFA 55MB, its anti-icing properties having been previously covered by other publications.
1963-01-01
Technical Paper
630254
Andreas B. Rechnitzer
Man’s knowledge of outer space far surpasses his knowledge of the oceans’ depths, but the development of functional submersibles has provided new pathways to factual information of suboceanic phenomena. These vehicles afford many advantages over remote controlled devices, as this paper points out. However, experience has proved that adequate investigation can be accomplished only by manned vehicles, utilizing trained operators in situ and the uncomparable observational capability of the human eye.
1963-01-01
Technical Paper
630255
John A. Pritzlaff
The integrated system vehicle for deep underwater work has many limitations that are successfully overcome by the design of modular type vehicles. The modular type is adaptable to a wider range of oceanographic programs because of its operational selectivity, small size, component interchangeability, and versatility. It may be operated from a parent vehicle or as a free unit, manned or unmanned. This paper reviews the capabilities of both the integrated and the modular types and reviews accomplishments to this date.
1963-01-01
Technical Paper
630252
J. W. McCown, C. R. Wilks, L. J. Gagola
This paper reviews studies to develop vacuum brazing procedures for fabricating D-36 (Cb-10% Ti-5% Zr) columbium and TZM (Mo-0. 5% Ti-0. 07% Zr) molybdenum honeycomb sandwich structures. Braze alloy flow temperatures ranged from 1800° to 3300° F. Higher remelt temperature braze alloy systems, as well as conventional brazing alloys, were investigated. The higher temperature remelt systems show promise but require additional development. Honeycomb sandwich panels which simulate application on an aerospace vehicle, either as hot monocoque structure or as modular heat shields for a double-walled structural concept, were fabricated for evaluation by structural and thermal testing.
1963-01-01
Technical Paper
630253
Laurence L. Jackson
The deepest known trench in the oceans is Challenger Deep at 35,800 ft. However, only about 2% of the oceans measure deeper than 20,000 ft. Present-day submersibles are generally limited to depths less than 400 ft. Between 400 and 20,000 ft lies over 90% of the ocean volume. The ability to use this volume would enhance the following military characteristics of submarines: concealment; invulnerability from detection and attack; and ability to detect and attack surface shipping and other submarines. Such improved characteristics are considered necessary to assurecontinued control of the seas.
1963-01-01
Technical Paper
630258
H. E. West
That the igniter is much more than a firing device in the combustion chamber of a gas turbine engine is ably demonstrated by the tests discussed here. Its requirements under various operating conditions and its effects on design and maintenance of a gas turbine have led to developments of new types that have longer life and higher performance rating. One of these types is the high energy igniter designed by Rolls-Royce. The kinds of tests to which this igniter has been subjected emphasize the related efficiencies and their economic import in engine and igniter designs.
1963-01-01
Technical Paper
630259
M. W. Burgher
The gas turbine specification and specific areas of the engine design establish the boundaries within which the ignition manufacturer can design ignition system components. It emphasizes the effect of the relationship on the size, weight, cost, and reliability of the ignition system and suggests considerations that can improve these factors. It suggests the need for improved high frequency spark measuring equipment and techniques, and standardization of requirements and ignition system components as aids for future refinements.
1963-01-01
Technical Paper
630256
H. J. Fisher
Electro-explosive devices (EED’s) are characterized by their input requirements and output characteristics. Generally, the input energies for EED function may be high as in exploding wire devices, or low as in conventional “hot wire” systems. The electro-explosive interface problem is considered here. Safety and reliability factors are implicit in the design of either category of initiator, such as: the insensitivity of the pyrotechnic or explosive used; the resistance to extraneous electrical energy from rf sources; and the stability to environments consisting of high thermal and/or high density nuclear radiation conditions. Methods of designing EED’s for missile and space applications are also considered.
1963-01-01
Technical Paper
630257
L. I. Knudson
Ignition systems are categorized into two general groups: one producing energy in short high power bursts and the other in long low power bursts. Capacitor discharge systems for jet engines and exploding bridge wire type of initiators are of the first group. Constant current transformers and induction vibrators, producing high tension, glow plugs and hot wire initiators utilizing primary power directly are in the second group. Methods of control, advantages and limitations, and susceptibility to external stimuli are compared with emphasis on electro-magnetic compatibility. Capacitor discharge systems for exploding bridge wire initiators are particularly emphasized because of their increasing use on missiles.

Filter

  • Range:
    to:
  • Year: