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1975-02-01
Technical Paper
750095
M. Beltzer, R. J. Campion, J. Harlan, A. M. Hochhauser
Noble metal oxidation catalysts have been shown to convert gasoline sulfur to automotive particulate sulfate emissions. A study was carried out in a laboratory bench scale reactor to evaluate the effect of vehicle operating conditions and catalyst type on the conversion of SO2 to SO3. The factors studied included catalyst temperature, exhaust gas O2 content and space velocity. The results are compared with data from a vehicular study designed to assess total sulfur emissions from catalyst-equipped cars. This study indicates that control of exhaust sulfate emissions may be achieved through close control of the oxygen content of exhaust gas and that the choice of catalyst affects the degree of conversion of SO2 to SO3 and the amount of oxidized sulfur retained in the catalyst system.
1975-02-01
Technical Paper
750097
Robert H. Hammerle, Mati Mikkor
With the use of a simulated exhaust system, the sulfuric acid and sulfur dioxide emission from a monolith noble-metal oxidation catalyst (Engelhard IIB) is measured. It was found that the storage rate of sulfur onto an initially sulfur-free catalyst decreases to a few percent of the sulfur rejection rate within 3-4 h. The amount of sulfur on the catalyst when the catalyst is in equilibrium with 20 ppm sulfur in the gas phase varies between 0.3 weight percent of the catalyst at about 400°C to 0.1 weight percent at 600°C. The sulfur can readily desorb from the catalyst if the gas phase sulfur content is lowered or if the catalyst temperature is increased. It was found that the conversion of sulfur dioxide to sulfuric acid reaches thermodynamic equilibrium at temperatures of 400-500°C and space velocities of 30,000 h-1. These conditions correspond approximately to a small V8 engine at 20 mph cruise.
1975-02-01
Technical Paper
750090
Ronald L. Bradow, John B. Moran
A review of the available data on sulfate emissions methods and emissions rates from both catalyst-equipped and noncatalyst cars has been made. Air-dilution methods of various sorts appear to give similar sulfates emissions results, comparable with those obtained by controlled condensation procedures. Mobile source SO2 measurements technology requires much more attention. At present, only the hydrogen peroxide oxidation to sulfate has been demonstrated to give reliable results. Summaries of several hundred catalyst and non-catalyst emission rates are treated to estimate California and 49-state emissions. A cruise-mode emission rate of about 0.03 g/mile appears appropriate for both monolithic and pelleted catalysts in 49-state cars.
1975-02-01
Technical Paper
750091
David A. Trayser, Ellsworth R. Blosser, Fredrick A. Creswick, William R. Pierson
The authors have investigated the emission of sulfuric acid and nitrates from a 1973 Ford 351C V-8 engine equipped with prototype 1975 emission controls and mounted on a dynamometer test stand. Tests were performed on unleaded fuel at 60 mph road-load conditions, using monolithic noble-metal catalysts and no catalyst, and at 60 and 30 mph road-load conditions using a pellet-bed noble-metal catalyst. Sampling for SO2 and H2SO4/SO3 measurement was effected at several points within the exhaust system as well as from a dilution tunnel where the exhaust was diluted ten-fold with filtered air. Samples collected in the dilution tunnel were analyzed for total particulate mass, sulfate, condensed water, and pH. Ammonia injection into the dilution tunnel on selected runs permitted collection of nitrate and HNO3 on the filters as NH4NO3. Nearly all of the fuel sulfur was emitted as SO2, and less than 1% as sulfate, in the absence of a catalyst.
1975-02-01
Technical Paper
750092
Ronald G. Bruce
It has been reported that automobile exhaust resulting from gasoline containing sulfur can produce a potentially harmful sulfuric acid mist when passed through an oxidation catalytic converter. In response to an Environmental Protection Agency (EPA) request, the National Petroleum Refiners Association conducted an industry survey to develop information concerning the impact of reducing the sulfur in unleaded gasoline to a maximum of 100 ppm. The survey showed that an estimated 361 new processing units would be needed at a cost of $3.7 billion. It further pointed out that it was probably beyond the capability of the already overloaded engineering/construction industry to complete such facilities within three years.
1975-02-01
Technical Paper
750119
W. J. Most, J. P. Longwell
Comparative testing of pure methanol, methanol/water blends and isooctane in single-cylinder engines has demonstrated that through proper utilization of methanol's fuel-lean combustion characteristics it may be possible to reach CO emissions of the order of 0.1 percent and NOx emission levels of less than 100 ppm in the raw (undiluted) exhaust. Exhaust treatment to remove unburned methanol and partial oxidation products might be required. Concomitant with decreased emissions are specific energy consumption improvements estimated to be in the range of 26 to 45 percent better than achievable with current gasolines and the associated low compression ratio engines and emission control systems. These energy consumption improvements are obtained by virtue of efficient lean operation and by utilizing the high octane values of methanol/water blends at high compression ratios.
1975-02-01
Technical Paper
750121
R. D. Fleming, T. W. Chamberlain
A study of methanol as an automotive fuel was conducted using a single-cylinder research engine, a 4-cylinder 122-CID (2,000 cc) engine, and an 8-cylinder 350-CID engine. Results showed that when using methanol as fuel, the single-cylinder engine could operate leaner than the multicylinder engines. This difference is attributable to air-fuel mixture maldistribution associated with the multicylinder engines. Steady-state fuel economy and emissions data are presented and discussed. Results indicate that fuel economy (on an energy input basis) using methanol fuel is about 5% improved as compared to gasoline fuel economy and with substantially lower nitrogen oxides emissions for methanol.
1975-02-01
Technical Paper
750120
N. D. Brinkman, N. E. Gallopoulos, M. W. Jackson
Current national interest in alternative fuels has placed considerable emphasis on alcohols, mainly methanol and its blends with gasoline. Vehicle studies with methanol-gasoline and ethanol-gasoline blends showed that adding alcohol to gasoline without carburetor modifications decreased carbon monoxide emissions, volume-based fuel economy, driveability, and performance. Depending on the carburetor's air-fuel ratio characteristics, hydrocarbon and nitrogen oxide emissions and road octane are either increased, decreased, or not affected. These effects can be explained on the basis of changes in stoichiometry, energy content, combustion temperatures, and detonation resistance caused by the addition of alcohol to gasoline.
1975-02-01
Technical Paper
750123
J. C. Ingamells, R.H. Lindquist
Laboratory and road tests showed methanol to be an effective octane booster. Adding 10% methanol to unleaded gasoline raised the Road octane 2-3 numbers. However, significant deterioration in driveability tests occurred because of methanol's “leaning” effect. The water sensitivity of methanol/gasoline requires a separate fuel distribution system. Fuel storage in a vehicle must be protected from water absorption. Corrosion and degradation problems occur in the vehicle fuel system where methanol/gasoline mixtures contact lead, magnesium, aluminum, and some plastics. Methanol burned more efficiently under lean conditions than gasoline. However, the cold start problems require a separate starting fuel. Methanol is not a useful fuel additive for existing unmodified cars. Methanol could be used effectively in special vehicles designed to handle the corrosion, water absorption, and vaporization characteristics.
1975-02-01
Technical Paper
750173
Donald J. Pozniak
Nitric oxide can be chemically reduced in a vehicle exhaust system if hydrocarbons are supplied to high-temperature exhaust gas near the engine exhaust valves. Ethane was injected into the exhaust ports of engines equipped with either stainless steel or ceramic thermal reactors. Thermal decomposition of the ethane provided hydrogen and hydrocarbon radicals for the gas phase chemical reduction of nitric oxide formed in the engines. Although significant reductions of nitric oxide were achieved, severe spark retard was required to attain the elevated exhaust temperatures required to effect the nitric oxide reduction. Furthermore, carbon monoxide, hydrogen cyanide, and ammonia were formed, especially with the stainless-steel reactors. In view of these findings, this scheme for reducing nitric oxide emissions is not felt to be practicable for automotive application at this time.
1975-02-01
Technical Paper
750172
Richard A. Gast
The Pulsair concept utilizes inherent exhaust system pressure pulsations to induce secondary air into reciprocating engine exhaust ports for oxidation of unburned hydrocarbons and carbon monoxide. High-speed check valves are actuated by subambient exhaust pressures which arise from reflected exhaust “blowdown” pressure waves. For multicylinder engines, a single check valve set can be used effectively to supply air to an entire exhaust manifold. Experiments with V-8 engines and simple acoustic wave theory have been used to define system fundamentals and design techniques for obtaining high induced airflow rates at specified engine speeds. Procedures are outlined for adapting the concept to L-4, L-6, and V-6 engines. The Pulsair system does not affect net engine power and is potentially less complex than typical air pump systems.
1975-02-01
Technical Paper
750162
L. Phoenix
This paper takes a wide view of what constitutes the automotive environment as seen by the electronic engineer. It discusses how the design of automobile electronic equipment is affected by the cost attitude of the automotive industry, the servicing facilities available, the automobile environmental conditions, and the specification of these conditions by the automotive engineer.
1975-02-01
Technical Paper
750167
John S. Collman, Charles A. Amann, Charles C. Matthews, Richard J. Stettler, Francis J. Verkamp
The intensive search for an alternative low-emission powerplant for passenger cars has led to a re-evaluation of the gas turbine for this type of service. The GT-225 engine was designed as a research tool to aid in making such an evaluation. Factors which received special consideration in making design decisions included exhaust emissions, fuel economy and drivability. An extensive combustor development effort was undertaken to achieve low emissions. The engine has been installed in a test-bed vehicle to permit evaluation of emissions and other factors under actual driving conditions. Vehicle tests of the engine fitted with a low-emission combustor demonstrated the following emissions: 0.11 g/km (0.18 g/mile) HC; 1.2 g/km (2.0 g/mile) CO; and 0.23 g/km (0.38 g/mile) NOx.
1975-02-01
Technical Paper
750158
Herbert Tesarek
In an attempt to abate soot emissions, diesel fuel for a direct-injection, single-cylinder diesel engine was step-by-step replaced with natural gas. The gas was introduced into the intake system. As a result of this, soot emissions were decidedly improved and maximum power was increased. As an undesirable secondary effect, especially at small loads, there was an unacceptable increase in brake specific gas-diesel fuel consumption and an increase in emission of harmful gaseous exhaust components. Exhaust gas recirculation and throttling were investigated as possible countermeasures. Both are capable of reducing the emission of poisonous gaseous exhaust components at high gas rates, without essentially increasing soot emission. Also, higher part-load consumption could be reduced by these countermeasures.
1975-02-01
Technical Paper
750175
David S. Dickey
A steady-state, mass-transfer-limited monolith model has been formulated to investigate analytically the effects of gas-phase phenomena on converter performance. Gas-phase reaction kinetics are included to demonstrate the significance of noncatalytic processes to overall conversion, especially at temperatures above 850°K. Developing boundary layers in the monolith channels are shown to increase the calculated conversions relative to conditions for fully developed, laminar flow. Substantially different conversion efficiencies are predicted for various hydrocarbon species because of the effect of component diffusivity on convective mass-transfer rates. The expression for the gas-phase oxidation of hydrocarbons indicates that carbon monoxide forms as an intermediate product. Experimental evidence of carbon monoxide formation in conjunction with high concentrations of inlet hydrocarbons has been modeled with this partial oxidation reaction.
1975-02-01
Technical Paper
750159
Thomas E. Ritter, Charles D. Wood
The feasibility of converting a conventional unthrottled 2-stroke diesel engine to gaseous fuel was investigated. The development work was performed in two phases. In phase 1 the conversion concepts were built and tested on a single-cylinder engine. In phase 2 one of these was put into effect in a 6-cyl (DDA 6V-71) engine. The design concept with the most promise includes a divided combustion chamber utilizing a gas inlet valve in each chamber and a spark plug ignition source located in the prechamber. The concept has the potential of reducing the exhaust emissions well below the levels now existing in commercial diesels without exhaust smoke and odor and with equivalent fuel consumption and horsepower, as demonstrated in the single-cylinder conversion. Further development work remains to be done to perfect the concept for the multi-cylinder engine.
1975-02-01
Technical Paper
751177
A. W. Waterman
Up to 5% of an airplane's fuel might be saved by taxiing with powered wheels. Additional benefits in conservation are reduced noise, jet blast, and emissions at the terminal area. By using the airplane onboard auxiliary power unit (APU) to operate the traction-producing drives, an airplane self-contained ground-maneuvering capability is provided. Hydraulic power transmission for the wheel drives has the advantage in satisfying large horsepower demands for a small weight and volume penalty. Variations in the drive mechanism are based on the method of transfer of power to the wheels while preserving the present method of independent braking during airplane landings.
1975-02-01
Technical Paper
751097
H. L. BURGE, J. HARDGROVE, R. KOPPANG
The TRW Low NOx Burner was conceived and developed utilizing the substantial technical expertise acquired during development and production of combustion systems for rocket engines and auxiliary power units. The Low NOx Burner is based upon hydraulic and injection principles derived from the design of the Lunar Excursion Module lander rocket engine. This engine required high combustion intensities, turndown ratios and manned flight reliability. Using these basic principles, TRW has patented, developed and commercialized power burners which have demonstrated reduced pollutant levels and high thermal efficiencies. Gas, light and heavy oil burners firing over a 2 to 55 MBtu/hr have been developed and field tested. The TRW activity has also been expanded into demonstration programs to demonstrate similar performances and low emission levels in utility type boilers.
1975-02-01
Technical Paper
751056
P. H. Calder, P. C. Gupta
The current achievements of Concorde and its powerplant are summarised, and the route by which technology may be evolved for making further SST performance and environmental advances appropriate to a second generation aircraft is indicated. Experimental data on takeoff noise is discussed. Future improvements in turbine cooling technology applied to a turbofan of around 1.7 bypass ratio, together with possible future improvements in aircraft L/D and structure weight, should permit the development of an SST with substantial increases in payload percentage and range relative to Concorde while meeting current FAR Part 36 noise limits without a suppression system. The engine could be derived from the current Olympus 593 Mk 610.
1975-02-01
Technical Paper
751001
H. K. Newhall
This paper discusses basic combustion process modification as a means for emissions control. It has recently been shown that modified combustion systems can in principle lead to reduced emissions. Several of these systems, which fall into the broad category of stratified charge systems, will be discussed in this paper.
1975-02-01
Technical Paper
750972
D. E. Blandy
Two recently developed sheet products offer material cost savings opportunities of approximately $2.50 per typical car with catalytic conversion system. Galvalume sheet steel, an aluminum-zinc alloy coated sheet, has been used successfully for grass shields replacing type 1 aluminum coated sheet at an approximate savings of 25¢/lb. Chromized sheet, which has a diffused layer of ferritic stainless steel on both surfaces of a special low carbon sheet, is suggested as a substitute for 400 Series Stainless Steel at a material cost benefit of approximately 15¢/lb. Exhaust inlet tubes and convertor shells of Chromized have been successfully tested.
1975-02-01
Technical Paper
750969
Howard E. Williams
New OSHA requirements regarding the use of VCM (vinyl chloride monomer) have been found to present specific problems with certain sampling methods and analytical procedures. This report will attempt to define some of these problem areas.
1975-02-01
Technical Paper
750024
Colin R. Ferguson, Guido A. Danieli, John B. Heywood, James C. Keck
Measurements were made of exhaust histories of the following species: unburned hydrocarbons (HC), carbon monoxide, carbon dioxide, oxygen, and nitric oxide (NO). The measurements show that the exhaust flow can be divided into two distinct phases: a leading gas low in HC and high in NO followed by a trailing gas high in HC and low in NO. Calculations of time resolved equivalence ratio throughout the exhaust process show no evidence of a stratified combustion. The exhaust mass flow rate is time resolved by forcing the flow to be locally quasi-steady at an orifice placed in the exhaust pipe. The results with the quasi-steady assumption are shown to be consistent with the measurements. Predictions are made of time resolved mass flow rate which compare favorably to the experimental data base. The composition and flow histories provide sufficient information to calculate the time resolved flow rates of the individual species measured.
1975-02-01
Technical Paper
750017
Jose F. Requeiro
Teledyne Continental's new Red Seal industrial engine line incorporates the Controlled Pressure Combustion System (CPCS) featuring emissions control, fuel efficiency and driveability, without sacrificing maximum power. These new, low maintenance engines are based on time-proven mechanical components with a new cylinder head, carburetor and electronic ignition. The complete R & D history of the program is presented, covering cylinder head, carburetion and ignition system. The paper describes an Automotive Program with two cars, matched and optimized to meet the 1975 Light Duty Automotive Standards without using any exhaust after treatment or other emissions control devices.
1975-02-01
Technical Paper
750550
Richard A. Rudey, Erwin E. Kempke
Programs have been initiated by NASA to develop and demonstrate advanced technology for reducing aircraft gas turbine and piston engine pollutant emissions. These programs encompass engines currently in use for a wide variety of aircraft from widebody-jets to general aviation. Emission goals for these programs are consistent with the established EPA standards. Full-scale engine demonstrations of the most promising pollutant reduction techniques are planned within the next three years. Preliminary tests of advanced technology gas turbine engine combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft engines without adverse effects on fuel consumption. Fundamental-type programs are yielding results which indicate that future generation gas turbine aircraft engines may be able to utilize extremely low pollutant emission combustion systems.
1975-02-01
Technical Paper
750535
R. M. Wood, J. G. Tomlinson, D. L. Troth, J. J. Petraits
An experimental program was conducted to select a combustion system design for the 500 shp Model 250-C28 turboshaft/turboprop engine. The primary goals were: 1. Capability of complying with the Environmental Protection Agency (EPA) 1979 Class P2 turboprop engine emission standards. 2. Capability of ingesting a 100 ml slug of water in 1/4 s without flameout. The Model 250-C28 engine is an uprated version of the Model 250 (T63 military designation) production engine. The conventional Model 250 production combustor meets the EPA 1979 turboprop emission standards for NOx and smoke, but unburned hydrocarbons (UHC) and CO exceed the standards. Also, the water ingestion requirement for the Model 250-C28 exceeded the capability of the current technology conventional combustor. The emission and water ingestion goals of the program were met with a prechamber combustor design.
1975-02-01
Technical Paper
750618
John J. Schneider
Abstract During the early 1930's, the rigid airship was potentially the Queen of the Skies. The design, manufacturing, and operational techniques and the facilities had been developed over a 30-year span to the point where the airship easily exceeded contemporary airplanes in range and payload, and even productivity as well. Through a combination of circumstances, failures, and political expediencies, development of the rigid airship was terminated while development of the airplane and its propulsion systems accelerated at a tremendous pace. There has been a number of attempts throughout the world in recent years to initiate airship development. The need for reduced energy usage and lowering of pollution, coupled with the need for transporting large, heavy, indivisible loads, do appear on the surface to be satisfied by the unique characteristics of the airship.
1975-02-01
Technical Paper
750617
R. D. FitzSimmons, R. L. Roensch
Comparisons are presented between the last U.S. SST design and results of recent progress on an advanced supersonic transport design. The results are shown of changing from a double-delta 2.7 Mach configuration to a modified arrow-wing 2.2 Mach design. Information is presented covering increased range, lower operating cost, reduced technical risk, and noise levels that meet anticipated requirements of society. The main emphasis in this paper is on an aerodynamic lift-to-drag ratio of 10 and how this high level of aerodynamic cruise efficiency can be substantiated for a tailored design.
1975-02-01
Technical Paper
750586
T. L. Galloway, J. A. Stern
Short-haul air transportation is one of the most challenging of all modes of transportation. The short-haul passenger market represents approximately 40 percent of the total U.S. domestic market. This market can be classified by passenger density. A Douglas study, funded under a NASA contract, is reviewed. This study indicates potential means for successfully meeting the challenges in the market with under 500 daily passengers. Initially, the market is investigated and realistically defined; then aircraft requirements that are economically viable and environmentally acceptable are established to satisfy the market. To meet the challenges of this market, the need for economic viability and environmental acceptability requires the careful balancing of performance, technology, and design-to-cost concepts. A general aviation manufacturer participated in evaluating design-to-cost options and three airlines provided guidance for operating realism.
1975-02-01
Technical Paper
750590
Bruce Aubin
This paper is an attempt to establish the rationale for monitored, or reduced, thrust operations in Air Canada and their effect on safety, reliability, aircraft performance and economics. It explains why an approach to operating at less than maximum takeoff thrust has been developed. It demonstrates the effects of monitored thrust on power plants, operating temperatures, and training procedures. Lastly, the paper explains how monitored thrust will produce an improvement in the environment and how it achieves an incremental saving in fuel.
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