Search Results

CONSTANT improvement in airplanes involving increased speeds and increased maneuverability permits of their performing evolutions that were not contemplated when present strength requirements were established. Additional data and experience, however, make possible the breaking down of some of the problems involved into components that can be treated rationally and others that must still be handled empirically. A method for determining load factors in the high-angle-of-attack condition by the use of two rational variables and one empirical coefficient is described and applied to some 19 airplanes, the results being compared with the factors established by current practice.

This paper addresses the fundamental mechanisms associated with Buzz, Squeak and Rattle (BSR) sounds and the analysis of their acoustic signatures. These sounds will be generated and analyzed individually with a conventional popular metric in the presence of typical background sound. Baseline computations of the background will be performed for comparison. This paper will present a look at the sensitivity of the current popular metrics ability to identify BSR specific sounds in the presence of background noise levels. This understanding of the measurement and quantification of the specific BSR sound signatures can be the basis for design target setting with respect to specific BSR phenomena. As well, this can lead to a better understanding of whether or not it is appropriate to quantify these phenomena together or if there is a need for a “Rattle Trap” metric, a “Buzz Trap” metric or a “Squeak Trap” metric.

This paper describes a method for studying reactions of hydrocarbons in S.I. engine exhaust gases. The reaction of ethane is described using an Arrhenius model (experimentally E = 86,500 cal/mole) for the rate of ethane diappearance and empirical correlations for distributions of the products carbon monoxide, ethylene, formaldehyde, methane, acetylene, and propane as a function of the fraction of ethane reacted. The results show that the nature of partial oxidation products from a nonreactive hydrocarbon may be less desirable from an air pollution viewpoint than the initial hydrocarbon.

The reaction of ethylene in engine exhaust gases has been studied using a turbulent plug flow reactor. The effects of ethylene, oxygen, and nitric oxide concentrations and of temperature on the reaction were investigated. Nitric oxide was found to be consumed in the reaction and partially converted to nitrogen dioxide. For temperatures up to 649 °C, little formation of carbon dioxide was measured for a reaction time of 140 ms. Increasing the oxygen concentration above 4% gave no increase in the oxidation rate. The Kinetics of the reaction were such that it was not possible to describe the reaction with a simple Arrhemus rate expression. The only other hydrocarbon found was a trace of acetylene at a reaction temperature of 649 °C.

This paper presents results of studies investigating the reactivity of primary reference fuel blends in a motored research engine. Reactivity was quantified by measuring exhaust manifold carbon monoxide concentration [CO], cylinder pressure histories, and in-cylinder gas composition. The fuels used were n-heptane (0 PRF), isooctane (100 PRF), and blends of the two with octane values of 0, 25, 55, 63, 75, 87, and 100. A supercharged single-cylinder engine was motored at a constant engine speed and constant inlet pressure as the inlet gas temperature was increased by manifold heating until either the fuel/air mixture autoignited or the maximum temperature of the facility (490 K) was reached. In-cylinder gas samples were obtained and analyzed by gas chromatography for overall fuel reactivity and for the concentrations of light hydrocarbon (

Results are presented regarding the effects of backlighting liquid crystal displays (LCD's) by electroluminescent (EL) lamps and the effects of general ambient lighting. The interest in LCD's with EL backlighting stems from this display concept's compatibility with night vision goggles (NVG's). The results indicate that increased backlighting enhances transflective dichroic LCD readability in contrast to an earlier study utilizing a reflective LCD which concluded that backlighting has an adverse effect.

The evaluation was made on phosphors of seven different colors in current use under high brightness ambient conditions. As the result, the use of an appropriate filter (e.g. Neutral Density Filter of 3.4% transmittance) allows the 3-digit numbers in the display of about 400cd/m2 to be read correctly under an ambient illuminance of 50,000 lx, regardless of colors used. On the contrary, when a filter of high transmittance, such as Neutral Density Filter of 10%, is used, the required display luminance in the same ambient differs depending on phosphors; 300cd/m2 for reddish orange to 1,600cd/m2 for greenish yellow.

This paper presents the method applied in the development of an optimized powertrain mounting assembly for a Light Truck Diesel or Pick-up application. The focus of this optimization is to improve the vibration insulation and consequently improve the NVH (Noise and Vibration Harshness) quality of the vehicle. The paper describes the basic mounting design and manufacturing constraint, the simulation modeling basis, inputs required to perform the computational simulation, the experimental work required, also the method used to determine the center of gravity and rotational inertia of the powertrain and a general mounting tuning strategy. The experimental results for an optimized version are also presented and compared to the original one.

Living in an age of accelerating change, containerization was still being predicted five years ago, and today containers are the established mode. This paper presents the protential of containerization, stating that it will add to highway traffic, not diminish it. It also offers conservation, environmental, and capital benefits for utilizing containerization.

Structured problem solving methods are utilized in the automotive industry for the efficient resolution of quality issues in manufacturing. Several problem solving methodologies have been developed, each with the same basic philosophy to prevent problem reoccurrence. Numerous barriers inhibit the effectiveness of problem solving. Although some tactical barriers may be overcome by training personnel, the majority of barriers are strategic or cultural in nature. Barriers at these two levels can only be removed by management level personnel. Management must shift its focus from firefighting to problem prevention. This shift can only be realized if problem prevention is addressed during design.

A review of the UM series and of NCSS, NASS, CPIR and FARS Files, as well as Michigan accident data files was undertaken, as well as a review of the NTSB “Rear Seat Study”. From these files rear seat occupany is approximately 10%, with children 6 years of age or less being 1/5th of these. About 50-60% of those in the sear seat are adults. Most of the injuries are at the lower AIS levels, with adults being more seriously injured. Of the more serious or fatal injuries, the head and face predominate by far, in all types of crashes involving unrestrainded rear seat occupants. When belts are worn there are few seriously or fatally injured rear occupants and of these, the abdominal area predominates. From available data, rear lap-belted passengers have the same MAIS level (or less) when compared to their front seat lap-shoulder belted counterparts.

This paper examines how a human torso rebounds from seats in low to moderate speed collisions. A torso model and a seat model are combined and numerical integration is used to predict the response characteristics.

The rising cost of new equipment has forced the user to consider methods of maintaining an updated fleet. The rebuilding of existing aerial device equipment has been performed with great success at substantial savings.

This paper discusses in detail the recommended procedures for rebuilding internal combustion engines; explains how decisions to rebuild, replace, or reuse engine parts are arrived at by experts, and describes how each part of the engine is examined, cleaned, and tested to insure maximum performance. When an engine should be rebuilt, what rebuilding entails, how to evaluate a repair shop by its equipment, and similar valuable information regarding engines and their maintenance are topics considered.

With the aim of building up an European expertise in manned spaceflights, ESA, with the assistance of the European scientific community, has carried out a large amount of studies and several experimental campaigns involving multinational crew in conditions of isolation and confinement or in long duration BedRest. The first experimental campaign, called ISEMSI-90, was performed in 1990 at the Hyperbaric Complex of NUTEC in Norway and involved a crew of 6 men during 28 days; the second one, called EXEMSI-92, was performed in 1992 at the Hyperbaric Complex of DLR in Germany and involved a crew of 4 (3 men and 1 woman) during 60 days. The third campaign, called HUBES, has been performed in 1994 at the Simulator of the Mir space station located at IBMP in Russia, and involved a crew of 3 men during 135 days.

After being in operation since 1989, the 25% / 20% model scale wind tunnel of University of Stuttgart received its second major upgrade in 2016. In a first upgrade in 2001, a rolling road with a 5 belt system from MTS was installed. This system includes a steel center belt to simulate the road underneath the vehicle and four FKFS designed rubber belts for wheel rotation. The recent upgrade now enables the wind tunnel to be used not only for standard, steady state aerodynamic measurements but also for measurements of unsteady aerodynamic effects. This enables the use of the FKFS swing system as a standard measurement technique. Therefore, the former balance was replaced by a balance manufactured by AND with a high Eigenfrequency and the ability to sample the measurement data at up to 1000 Hz. The second large part of the upgrade was the replacement of the control system. With the new Wind Tunnel Control System (WCTS), control system.

The relative newness of the DC-8-60's plus their advanced aerodynamic and structural technology combined with the CFM56-2 high by-pass engine results in a modern, economic aircraft. FAR Part 36 Noise Requirements and the prospect of ever increasing fuel costs make the retrofit DC-8-60's a prudent investment. The type certificate for these re-engined aircraft will designate them as DC-8-70's. Performance improvements, noise reduction and reduced fuel consumption provide distinct and quantifiable benefits to the operators of the DC-8-70's. These benefits are verified by the results of certification flight testing and will be presented in detail.

In recent years the number of warning functions in cars has grown rapidly. Traditionally these have been single areas dedicated to specific warning functions. Manufacturers have found it difficult, time consuming and costly to respond to legislative changes or market variations. An information display was developed that is microprocessor driven and provides a single area displaying warning symbols supplemented by an alphanumeric read out. This comprised a 32 × 32 dot matrix and warning frame, backed up by a 14 segment, 10 × 2 character message centre. The Automotive Ergonomics Unit embarked on a joint programme with the company to evaluate the information display. The ergonomics evaluation addressed itself to the recognition of the warning symbols in dot matrix and conventional ISO style format. An experiment was conducted in which 200 drivers tested the readability of 14 warning symbols when presented in dot matrix and conventional ISO style format.

A new method for processing data from time-accurate point measurements has been developed in order to investigate periodic elements of unsteady flow fields. The technique synchronizes the phase of measurements taken at different locations using a reference signal and collapses the spectral peak of interest onto a single frequency. The technique has been applied to data gathered using a time-accurate 5-hole probe behind a two dimensional body exhibiting vortex shedding. It has been possible to generate a sequence of instantaneous pressure and velocity fields which show the shedding of vorticity and total pressure loss to form a vortex street.

The range of motion of space suits has traditionally been described using limited two-dimensional mapping of limb, torso, or arm movements performed in front of an orthogonal grid. This paper describes an improved technique for recovering range of motion data, and a validation of the technique performed on an Extravehicular activity space suit. The new technique uses digitized data which is automatically acquired from video images of the subject. Three-dimensional trajectories are recovered from these data, and can be displayed using three-dimensional computer graphics. Target locations are recovered using a unique video processor and close range photogrammetry. Such data can be used in a wide variety of applications, including the animation of anthropometric computer models. The applications and limitations of the new technique are discussed.