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Viewing 161941 to 161970 of 188251
1974-02-01
Technical Paper
740475
Armen DerHohannesian
In a comparatively short time, air transportation has established itself as by far the dominant mode of intercity travel by common carrier and it will continue to be in the foreseeable future. However, the ability to continue to provide the safest and most convenient method of intercity transportation is in jeopardy if airport facilities are not available in time to accommodate adequately the levels of traffic which the demands for air service generate. This paper, although recognizing the importance of all airport system components, assesses the airfield capacity problem of today and the future and describes various influences that affect the airport operator's attempts to improve capacity.
1974-02-01
Technical Paper
740477
S. B. PORITZKY
Airport capacity at major airports is less now than it was only a year ago. The prospect of ATC technology improvements providing major capacity increases are much smaller than anticipated. The bigger payoff must come from a truly integrated total airport design, along with enough runways, adequate airport access, and in the long term airplanes which better fit high density airports. The paper outlines problems which are affecting airport capacity, and assesses the problems and prospects in achieving major improvements in airport capacity and reduction of delay. Many elements must work synergistically and must be drawn more closely together if there is to be a cost-effective, high-capacity airport system.
1974-02-01
Technical Paper
740473
T. E. Russell, R. E. Mattes
An evaluation of the influence of two classes of fuels and four types of lubricants on supersonic military interceptor aircraft performance at the airframe subsystem and engine component level is presented. Engine cycles representative of anticipated technology levels in the 1980 time period are analyzed to determine interceptor performance as a function of fuel and lubricant properties and temperature limitations. The relative allotment of available fuel heat sink between engine and airframe is also investigated to determine the primary factors affected by fuel interface temperature and to provide meaningful design guidance for future system applications. The results indicate that with an integrated systems approach to the management of the aircraft and engine system heat loads, JP type fuels and type 2 (MIL-L-27502) lubricants will meet the minimum requirements for advanced military systems.
1974-02-01
Technical Paper
740470
Joseph L. Johnson, Arthur E. Phelps
This paper summarizes the results of recent wind-tunnel investigations conducted to provide fundamental aerodynamic information on the upper-surface blown jet-flap concept incorporating high-bypass-ratio turbofan engines. The results of the investigations have shown the concept to have aerodynamic performance generally comparable to that of other externally blown high-lift systems. This paper will cover some of the more critical problem areas associated with this concept and will discuss solutions which have been found for these problems.
1974-02-01
Technical Paper
740474
Charles L. Blake
In order to formulate policy for the orderly development and use of the nation's navigable air space, federal agencies such as the FAA and the Department of Transportation have launched several programs to determine aviation requirements for the next 10 years. This paper outlines their conclusions concerning airborne activities such as flow control, approach and departure control, wake vortex problems, and operating procedures as well as airport capacity and ground operations. The impact of the FAA's Research and Development Program and the implications of the current fuel shortage and economic situation are also discussed.
1974-02-01
Technical Paper
740471
M. K. Bowden, J. H. Renshaw, H. S. Sweet
In a discussion of STOL vehicles with conventional high-lift devices, the need for efficient power-augmented lift systems is presented and the implications of quiet operation are noted. The underlying philosophy of a promising hybrid lift system with major interactions between aerodynamic, thermodynamic, acoustic, and configuration design technologies is derived. The technique by which engine and airframe-related characteristics for this application may be matched in an optimum manner is described and illustrated by describing the features of a particular short-haul commercial STOL vehicle.
1974-02-01
Technical Paper
740573
Harald J. Schimkat
The philosophy, development, and optimization of two Volkswagen experimental safety vehicles are presented: the ESVW I and the ESVW II. The optimization processes for crashworthiness and occupant restraints are discussed with respect to efficiency and to cost/benefit considerations.
1974-02-01
Technical Paper
740572
Patrick M. Miller, Melvin O. Ryder, Norris E. Shoemaker
Research programs conducted at Calspan to improve structural crashworthiness of subcompact cars are described. In two separate but related investigations, front structural designs intended to improve crash energy management were developed and adapted to a Datsun 510 and Chevrolet Vega. The prototype structure developed for the Datsun 510 was nominally consistent with present production manufacturing techniques and did not interfere with normal packaging requirements. This prototype design was evaluated through a series of 50 MPH (80 km/hr) flat barrier tests. Excellent passenger compartment integrity and crash energy management was demonstrated for this prototype automobile. The structural system developed for the Chevrolet Vega was similar in concept to that of the Datsun; but manufacturing requirements were relaxed in this effort.
1974-02-01
Technical Paper
740571
L. M. Shaw, G. F. Brammeier, R. L. Anderson
This paper summarizes the results of a research program, performed by Ultrasystems, Inc. and funded by the National Highway Traffic Safety Administration, to develop and improve methods for characterizing automobile front end structures. Computer simulations of each structure and crash environment were conducted using an existing computer simulation program. Two front end structures, a ramped fixed-force system and a variable stroke velocity-sensitive system, were incorporated into bogey vehicles which were crash-tested into a rigid barrier, a variable rigidity barrier, each other, and production vehicle front structures. These test results provided data by which computer simulation of the crash conditions were verified, providing a high degree of confidence in analytical representation of the structural crash responses. The empirical data were extended to other crash environments using the computer simulation techniques.
1974-02-01
Technical Paper
740583
Ulrich Seiffert, Wilfried Schwanz
For three given deceleration pulses of defined shape and peak magnitude, total velocity change was varied from 20 to 40 mph by changing duration of the pulse. Several restraint systems were compared, for these combinations of speed change and pulse shape, using head injury criterion, chest severity index, and femur loads to evaluate potential injury. Limit curves for each restraint are developed in terms of velocity change and peak deceleration, and the significance of these curves is discussed.
1974-02-01
Technical Paper
740584
Richard W. Carr, W. J. Nolan
The emphasis that has been placed on occupant safety in the space program and on our nation's highways during the past decade has resulted in the development of concepts and materials which significantly improve the performance characteristics of personnel restraint systems. However, the basic design of restraint systems presently used in Army aircraft has not been changed in many years, and the systems in use are not optimized to the practical limits of existing technology. In an effort to rectify this situation, modern restraint system technology was surveyed and a proposed military specification defining a forward-facing restraint system for use in Army aircraft was formulated. The materials, design concepts, and features found desirable for maximizing protection were included in the specification.
1974-02-01
Technical Paper
740587
Acen Jordan
This paper deals with the design concepts and development of a sled test compartment which exhibits yaw and pitch displacements as a function of the applied sled deceleration pulse. It outlines the program in which it was developed and notes the qualitative differences encountered when testing with these additional motions as opposed to testing with a fixed sled compartment.
1974-02-01
Technical Paper
740585
T. O. Jones, W. A. Elliott
Design validation of crash sensors in the vehicle barrier impact environment is difficult and costly. The objective of this paper is to outline a method of developing optimum crash sensor mounting utilizing reduced-scale physical models. This technique incorporates design tools that are readily accessible during early vehicle concept stages which will allow mechanical impedance checks of the crash sensor to vehicle structure interface at significantly lower cost than full size prototype testing. Basic equations and methodology are presented with experimental correlation data.
1974-02-01
Technical Paper
740582
Dieter Adomeit
This force limiter produces a belt force so that at the maximum requested crash-velocity and each lower one the maximum possible relative forward displacement between passenger and vehicle will be nearly used. Thereby, the passenger loads by the belt will be reduced, as well as the decelerations effecting the passenger, at a lower than the maximum requested crash-velocities in accident statistics, injuries by the belt will be effectly reduced, mainly for people of fragile contitution. The princip of the force limiter is a hydraulic throttling member. Due to the relative speed between the passenger and the vehicle the force limiter produces a belt-force according to its F-vrel.-ratio. PROCEEDING - 1. the mathematical analogue-digital simulation of a simplified passenger-vehicle-model in order to get an optimized F-vrel.-ratio of the force limiter 2. construction of a test unit of a force limiter to approximate the theoretical foundings by hardware.
1974-02-01
Technical Paper
740581
Juichiro Takada
Seat belt systems can be considered as the most convenient and practical system for occupant protection in automotive crash situations. Takata Kojyo Co., Ltd. has been striving to design and create a seat belt system that would be both practical and effective in absorbing impact energy with no injury in high speed crashes. In our search for more effective seat belt systems, we have conducted various comparison tests between conventional webbings and our newly developed webbing in regard to rheological property. 1. In regard to the dynamic performance of the webbing, the quantity of absorbed impact energy and the rate of absorbing energy were obtained and compared through tests at various impact speeds. 2. Dummy tests were conducted in our laboratories to compare the improved Takata energy-absorbing (EA) webbing with conventional webbing. The results showed the conspicuous superiority of the Takata webbing over the conventional types. 3.
1974-02-01
Technical Paper
740529
J. T. Wentworth
The effects of combustion chamber shape and spark location on exhaust NO and HC emissions were investigated using a single-cylinder, 4-stroke, reciprocating, spark ignition engine. A total of 21 spark locations were evaluated in three combustion chamber configurations. The chamber shapes included a modified wedge, a disc, and a modified hemisphere. The engine was operated at constant speed and airflow, with optimum spark timing and peak NO air-fuel ratio. Both combustion chamber shape and spark location had substantial effects on NO and HC emissions. Deductive prediction of these effects was not possible due to incomplete knowledge of the patterns of pollutant distribution and mixture movements within the combustion chamber. It is recommended that chamber shape and spark location effects be evaluated experimentally in any new engine design.
1974-02-01
Technical Paper
740536
John B. Heywood, Michael K. Martin
A methodology is presented with which aggregate emissions from the in-use automobile population can be calculated for any given calendar year. The data base needed for such a calculation is discussed, and areas in which further research is needed are pointed out. Results of a series of calculations are then presented showing the effect on aggregate emissions of various control strategies. The effects of an inspection/maintenance and retrofit program, different vehicle population growth rates, catalyst deterioration in use, and various schedules of new car emission standards for post-1975 vehicles are presented. It is shown that the rate at which old, higher-polluting vehicles are retired from the in-use vehicle population is the major factor in determining the rate at which aggregate emissions will decrease in the 1970s, with the precise level of post-1975 standards only becoming important in the 1980s.
1974-02-01
Technical Paper
740502
H. R. Leslie, J. A. Bennett
It is hypothesized that the potential value of powered lift may be greater for transport applications requiring RTOL and CTOL field lengths than for those requiring STOL performance. Thus, it is implied that powered lift can be applied effectively to aircraft designed for medium and long haul, as well as short haul. This premise has been reached on the basis of observed trends in direct operating cost, mission fuel consumption, and, most significantly, community noise footprint areas for both powered lift and conventional mechanical flap configurations. Some pertinent results from recent NASA-sponsored configuration design and system studies for quiet short haul and fuel-conservative aircraft are discussed, and further data are developed to explore the potential value of incorporating powered lift concepts in advanced aircraft designs for medium and long haul applications.
1974-02-01
Technical Paper
740521
R. M. Reuter, J. E. Robinson
During the fall of 1971, the Coordinating Research Council conducted a test program at Yuma, Arizona, to investigate a drivability test procedure and the effects of fuel volatility on drivability during hot weather (90-100°F). The procedure included evaluation of vapor lock, hot start and run, and traffic driveaway. In phase I, 12 late-model automobiles and two fuel series were evaluated. In phase II, four cars and four raters were used to evaluate repeatability and reproducibility. Traffic driveaway of individual cars was related to fuel volatility but could not be defined by a general volatility factor for all vehicles. Vapor lock, as in the past, was related to front-end volatility. A usable procedure was demonstrated; however, it was shown that for traffic driveaway, the influence of the rater should be reduced.
1974-02-01
Technical Paper
740564
George P. Gross
Automotive exhaust emissions of polynuclear aromatic (C16+) hydrocarbons (PNA) were reduced by 65-70% by current emissions control systems and by about 99% by two experimental advanced emission control systems. At a given level of emission control, PNA emission was primarily controlled by fuel PNA content through the transient storage of PNA in engine deposits and their later emission under more severe engine operating conditions. A relatively minor contribution to PNA emission was made by PNA synthesized from lower molecular weight fuel aromatics, particularly C10-C14 aromatics. Deposit-related PNA emissions were linearly correlated with the PNA content of the deposit formation fuel. In comparison with a fuel of field-average PNA content (0.5 ppm benzo(a)pyrene), a field-maximum fuel (3 ppm) contained 4 to 7 times as much of three major PNA species and caused 3 to 5 times higher emissions of these species.
1974-02-01
Technical Paper
740563
M. Alperstein, G. H. Schafer, F. J. Villforth
This paper reports on the continuing development of Texaco's stratified charge engine combustion concept, the Texaco Controlled-Combustion System. TCCS conversions of the military L-141 engine have demonstrated inherently low exhaust emissions, multifuel capability, and improved fuel economy over the carburetted L-141 gasoline engine. Under contract to the U.S. Army Tank-Automotive Command, promulgated federal gaseous exhaust emissions standards were met in a naturally aspirated TCCS engine-powered M-151 vehicle equipped with EGR- and Texaco-developed exhaust catalysts. These low emissions were sustained for 50,000 miles (80,400 km) with moderate maintenance. The effects of different degrees of emission control and of multifuel operation on performance and fuel economy were characterized using a turbocharged L-141 TCCS engine-powered M-151 vehicle.
1974-02-01
Technical Paper
740538
Paul Kunselman, H. T. McAdams, Marcia E. Williams, Charles J. Domke
A mathematical model of an automobile's emission rate is described. This model can be used to calculate the amounts of hydrocarbons, carbon monoxide, and oxides of nitrogen emitted by individual or groups of automobiles being driven over any known driving sequence. The development of the model requires the amounts of three pollutants given off by individual automobiles over short duration driving sequences (modes). The validity of the model is investigated by using it to calculate the amounts of each pollutant given off by individual automobiles over the hot transient portion (first 505 s) of the Federal Test Procedure driving sequence. These predicted emissions are then compared with observed amounts emitted from each automobile. Further, the ability of the model to predict emissions is investigated in light of the reproducibility of actual automobile emissions measured in replicated tests. These analyses indicate that the model performs extremely well.
1974-02-01
Technical Paper
740551
Enrique Alfonso Susemihl, Allan I. Krauter
This paper describes an automatic stabilizing technique to prevent tractor jackknifing in tractor-semitrailer trucks. This stabilizing technique consists of the detection of the onset of a jackknife and the subsequent application of corrective action. The onset of a jackknife is detected through the behavior of the drive wheels, and the corrective action consists of a form of corrective braking; that is, the simultaneous operation of the antiskid systems at all axles of the truck. The results obtained in this study indicate that the stabilizing technique may effectively prevent the development of a tractor jackknife during braking. Furthermore, the implementation of this technique in a real truck would be relatively simple and require a minimum of additional hardware.
1974-02-01
Technical Paper
740561
T. V. DePalma, Vladimir Haensel, M. J. Sterba, J. E. Thoss
New cars represent a deliberate choice to lower emissions at the expense of fuel economy. This paper considers the compatibility of emission control and gasoline conservation for the automotive vehicle. It concludes that the use of catalytic converters in combination with higher ratio compression engines will allow us to regain pre-emission control fuel economy.
1974-02-01
Technical Paper
740215
D. A. Kendall, P. L. Levins, G. Leonardos
The odor profile method has been applied to the measurement and analysis of diesel exhaust odor. The human sensory panel has described the odor of diluted exhaust and analytical fractions isolated from the exhaust in terms of total intensity of aroma (TIA), and individual odor character notes. For convenience, diesel exhaust odor can be described in two character groups-oily-kerosene and smoky-burnt odor. The odorous species were determined by detailed chemical analyses supported by comparative data from reference compounds. To achieve reliable quantitative odor intensity measurements, it was necessary to present the odor panel with a series of concentrations (dilutions) of exhaust in air over a wide range. The odor intensity at a given exhaust concentration is computed from a least squares analysis of the entire panel data. The results demonstrate an odor intensity range of slight to moderately strong for diesel exhaust at 1000:1 dilution.
1974-02-01
Technical Paper
740307
N. E. Gallopoulos
The temperatures of engine oil, automatic transmission fluid, and differential lubricant were measured under a variety of steady-state conditions in 1969, 1971, 1972, and 1973 model year cars. Increases in engine speed and stroke and coolant temperature caused significant increases in engine oil temperatures. Engine load and coolant temperature increases appeared to be the principal causes of automatic transmission fluid temperature increases. Differential lubricant temperatures increased as engine speed and load increased, but speed was the more influential variable. The effect of ambient temperature was negligible in all cases over the narrow range of ambient temperatures investigated (65-85°F). Analysis of the data for year-to-year trends showed that only engine oil temperatures increased from 1969 to 1973. This trend, and several observations of engine oil temperatures greater than 300°F, suggest that improved resistance of engine oils to oxidative thickening may be required.
1974-02-01
Technical Paper
740216
P. L. Levins, D. A. Kendall, A. B. Caragay, G. Leonardos, J. E. Oberholtzer
Sensory studies have described diesel exhaust odor in terms of two major odor character groups-oily-kerosene and smoky-burnt. The odorous compounds have been identified in a detailed analytical chemistry-odor study. The oily-kerosene odor group is associated with the aromatic portion of the unburned fuel-principally, the alkyl substituted benzenes, indans, and tetralins. The smoky-burnt odors arise from partial combustion products of the paraffin and aromatic fuel components. Our studies have shown a good correlation between exhaust odor intensity and abundance of the partial combustion products. An analytical method has been developed, based on liquid chromatography, for the quantitative expression of exhaust odor intensity by measurement of the smoky-burnt odor group. Initial survey studies show the method to be applicable over a wide odor emission range. Fuel variation has little effect, whereas injector variables do influence odor intensity.
1974-02-01
Technical Paper
740213
C. William Savery, Richard A. Matula, Thomas Asmus
Only 2 of the 11 laboratories which have had diesel odor research projects underway during the last 16 years are still active in this research area. Much of the earlier work was devoted to developing diesel odor sampling, standards, and measurement techniques. Subsequently, work became generally focused upon the chemical identification of the odorants, a very difficult task due to their large number and low concentrations. After three years of concentrated effort involving the development of new odor measurement, sampling, and diesel exhaust analysis and preparation techniques, odorants comprising the two major diesel odor characteristics were identified. Compounds which are also components of diesel fuel were shown to contribute to one odor characteristic. Oxydized derivatives, generally of the same classes of compounds as those shown to contribute to the first odor characteristic, were tentatively identified by structure to comprise the second major odor characteristic.
1974-02-01
Technical Paper
740305
Michael R. Appleby, Alan G. R. Morris
This paper concerns automobile damageability resulting from low-speed collisions. Both crash test and real collision data related to speed and repair costs are examined, as are current legislation and new engineering practices and hardware designed to reduce damage. Examination of the data led to several conclusions, among them that, contrary to widespread belief, manufacturers are not building more fragile cars now. It was also found from crash test data that 1973 model cars will incur lower repair costs. Other consumer benefits and cost penalties are examined in detail.
1974-02-01
Technical Paper
740214
Charles T. Hare, Karl J. Springer, Joseph H. Somers, Thomas A. Huls
This paper describes the results of a public opinion survey on testing of diesel exhaust odors conducted during 1969 and 1970. Major goals of the research were to relate public opinion of the odors and the objectionability associated with them to odor intensity, and to obtain a dose-response curve as the primary result. The dose-response curve was needed to assess odor-control technology by providing a criterion for deciding whether or not the effect of a given control item would be noticed by the general public, reduce complaints, or be worth the cost and effort required for its implementation. The engine used as the live odor source for the subject research was a two-stroke cycle type similar to those used in many buses. This engine type was chosen because its exposure to the public in urban bus applications is very widespread, and because a large portion of the Environmental Protection Agency's odor research had been performed with similar engines.

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