Robert A. White

The Effect of Fumigation of Different Ethanol Proofs on a Turbocharged Diesel Engine

Lower proof ethanol is shown to be a viable alternate fuel for diesel engines. This type of ethanol can be manufactured economically in small distillation plants from renewable grain supplies. The effect of fumigation of ethanol proofs with a multipoint injection system on a turbocharged direct injection diesel engine at 2,400 rpm and three loads was studied. The addition of the water in the lower proofs reduced the maximum rate of pressure rise and peak pressure from pure ethanol levels. Both of these values were significantly higher than those for diesel operation. HC and CO emissions increased several times over diesel levels at all loads and also with increased ethanol fumigation. NO emissions were reduced below diesel levels for lower proof ethanol at all loads. The tests at this rpm and load with a a multipoint ethanol injection system indicate that lower (100 or 125) proof provides optimum performance.

Driving rate effects on crackling noise.

Many systems respond to slowly changing external conditions with crackling noise, created by avalanches or pulses with a broad range of sizes. Examples range from Barkhausen noise (BN) in magnets to earthquakes. In this Letter, we discuss the effects of increasing driving rate Omega on the scaling behavior of the avalanche size and duration distributions as well as qualitative effects of Omega on the power spectra. We derive an exponent inequality as a criteria for the relevance of Omega. To illustrate these general results, we use recent experiments on BN as a successful example.

Packaging and performance of an IGBT-based hybrid electric vehicle

A highly integrated hybrid electric vehicle of the series architecture has been built and tested. The vehicle essentially matches the performance of the stock car on which it is based-including full interior space, range, and dynamic performance. It approaches Federal ULEV targets with the engine in operation, and provides sufficient zero-emission (electric only) range for typical commuting. This is achieved by means of an integrated battery package, an air-cooled traction package, and industrial IGBT drives. The arrangement and package designs are discussed, with an emphasis on the electrical architecture and the power electronic drive trains. Operating results are reported.

VEHICLE ENERGY DISSIPATION DUE TO ROAD ROUGHNESS

SUMMARY Road roughness and surface texture are known to affect tire rolling resistance; however, little emphasis has been placed on the consequent changes in total vehicle energy dissipation due to road roughness. Thus, tire rolling resistance, in isolation from vehicle contributed losses such as dissipation in the suspension, appears to be a weakness in present evaluation procedures as they relate to fuel economy and pollution level testing: Recent work by Funfsinn and Korst has shown that substantial and measurable increases in energy losses occur for vehicles traveling on rough roads. The present investigation uses vehicle axle accelerations as a means of examining various road surfaces. Correlation with computer simulations has allowed the development of a deterministic road roughness model which permits the prediction of energy dissipation in both the tire and suspension as functions of road roughness, tire pressure, and vehicle speed. Comparison to the experiments of Korst and Funfsinn results in go...

Crackling noise, power spectra, and disorder-induced critical scaling

Crackling noise is observed in many disordered nonequilibrium systems in response to slowly changing external conditions. Examples range from Barkhausen noise in magnets to acoustic emission in martensites to earthquakes. Using the nonequilibrium random-field Ising model, we derive universal scaling predictions for the dependence of the associated power spectra on the disorder and field sweep rate, near an underlying disorder-induced nonequilibrium critical point. Our theory applies to certain systems in which the crackling noise results from an avalanchelike response to a (slowly) increasing external driving force, and is characterized by a broad power-law scaling regime of the power spectra. We compute the critical exponents and discuss the relevance of the results to experiments.

Optimal sizing and selection of hybrid electric vehicle components

Proper execution of a successful hybrid electric vehicle (HEV) design for transportation applications requires optimal sizing of key mechanical, electrical, and power electronic components. An active program for HEV development is described. The basic objective of an HEV design is to match the performance of a standard automobile while drastically reducing emissions. Constraints imposed while optimizing critical component selection are: vehicle range, acceleration, maximum speed, total emissions, cost, recharging, and driveability. A design example, based on readily available technology, is examined. It is reasonable to expect HEVs with good performance and order-of-magnitude emissions reductions.<<ETX>>

Multicomponent liquid and vapor fuel measurements in the cylinder of a port-injected, spark ignition engine

Fuel distribution measurements in the cylinder of a port-injected, spark ignition (SI) engine are presented with a discussion of the effects of injection timing, swirl, and engine speed. Planar laser-induced exciplex fluorescence (PLIEF) was used to study the liquid-and vapor-phase fuel distributions. Optical access to the cylinder was provided by placing a fused silica cylinder between the head and block of a production engine and using a Bowditch-type piston extension. Separate measurements were made with fluorescent tracers indicative of the light and heavy components of gasoline. A blend of four pure fuels mixed in proportions to give a distillation curve similar to that of gasoline was used for all measurements to achieve consistency in the base fuel as well as similarity with the vaporization characteristics of gasoline. These measurements indicate that the vapor-phase fuel distribution is strongly affected by the presence of liquid fuel in the cylinder, the amount of which varies with injection timing. The liquid that enters the cylinder is composed mostly of the heavy components of the fuel. Variations in the amount of swirl indicate that the vapor-phase fuel distribution also is affected by the bulk velocity field. Engine speed, over the range from 200 to 1200 rpm, did not exert a significant influence on the fuel distribution.

Low-sooting combustion in a small-bore high-speed direct-injection diesel engine using narrow-angle injectors

An optically accessible high-speed direct-injection diesel engine was used to study the effects of injection angles on low-sooting combustion. A digital high-speed camera was employed to capture the entire cycle combustion and spray evolution processes under seven operating conditions including post-top-dead centre (TDC) injection and pre-TDC injection strategies. The nitrogen oxide (NO x ) emissions were also measured in the exhaust pipe. In-cylinder pressure data and heat release rate calculations were conducted. All the cases show premixed combustion features. For post-TDC injection cases, a large amount of fuel deposition is seen for a narrower-injection-angle tip, i.e. the 70° tip, and ignition is observed near the injector tip in the centre of the bowl, while for a wider-injection-angle tip, namely a 110° tip, ignition occurs near the spray tip in the vicinity of the bowl wall. The combustion flame is near the bowl wall and at the central region of the bowl for the 70° tip. However, the flame is more distributed and centralized for the 110° tip. Longer spray penetration is found for the pre-TDC injection timing cases. Liquid fuel impinges on the bowl wall or on the piston top and a fuel film is formed. Ignition for all the pre-TDC injection cases occur in a distributed way in the piston bowl. Two different combustion modes are observed for the pre-TDC injection cases including a homogeneous bulky combustion flame at earlier crank angles and a heterogeneous film combustion mode with luminous sooting flame at later crank angles. In terms of soot emissions, NO x emissions, and fuel efficiency, results show that the late post-TDC injection strategy gives the best performance.

Low-Temperature Combustion Within a HSDI Diesel Engine Using Multiple-Injection Strategies

Low Temperature Compression Ignition (LTCI) combustion employing multiple injection strategies in an optical High-Speed Direct Injection (HSDI) diesel engine was investigated in this work. Heat release characteristics were analyzed through the measurement of in-cylinder pressure. The whole cycle combustion process was visualized with a high-speed digital video camera by imaging natural flame luminosity and three-dimensional-like combustion structures were obtained by taking flame images from both the bottom of the optical piston and the side window simultaneously. The NOx emissions were measured in the exhaust pipe. The effects of pilot injection timing, pilot fuel quantity, main injection timing, operating load, and injection pressure on the combustion and emissions were studied. Low temperature combustion mode was achieved by using a small pilot injection with an injection timing much earlier than TDC followed by a main injection after TDC. For comparison, experiment of a diffusion diesel combustion case was also conducted. Premixed-combustion-dominated heat release rate pattern was seen for all the low temperature combustion cases, while a typical diffusion flame combustion heat release rate was obtained for the conventional combustion case. Highly luminous flame was observed for the conventional combustion condition while much less luminous flame was seen for the low temperature combustion cases. For the higher load and lower injection pressure cases, liquid fuel being injected into low temperature premixed flame was observed for certain cases, which was different from the conventional diesel combustion with liquid fuel injected into hot premixed flame. Compared with the conventional diffusion diesel combustion, simultaneous reduction of soot and NOx was obtained for the low temperature combustion mode at both the same and increased injection pressure with similar operating load. For high load conditions, higher NOx emissions were obtained than the low load conditions with the same injection pressure due to a higher in-cylinder temperature under high load conditions with more fuel burned. However, compared with the diffusion combustion mode with a lower load at lower injection pressure, a significant reduction of soot was achieved for the high load conditions, which shows that increasing injection pressure greatly reduce soot emissions.Copyright

Extended Performance of Alcohol Fumigation in Diesel Engines through Different Multipoint Alcohol infection Timing Cycles

This paper reports on the results of using multipoint port injection alcohol fumigation of a four-cycle turbocharged diesel engine in which the fumigation injection cycle was varied. The three cycles, dual with one-half of the alcohol injection on each engine revolution, single with all of the alcohol injection during the open intake valve revolution, and single with all of the alcohol injected during the closed intake valve revolution, lead to significant differences in the engines pressure-volume history and alcohol energy replacement tolerance. The engine was fumigated with both industrial grade ethanol and methanol and complete performance and emissions data (excluding aldehydes) were measured at low, medium, and high values of BMEP and rpm.