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The use of cutting fluid in machining operations not only poses a health risk to workers but also creates environmental challenges associated with fluid treatment and disposal. In an effort to minimize these concerns and eliminate the costs associated with cutting fluids, e.g., purchase, maintenance, and treatment, dry machining is increasingly being considered as an alternative. This paper is focused on comparing dry and wet machining approaches from several perspectives, including air quality, product quality, and economics. Both experimental and analytical work is presented. Experiments have been performed to determine the effect cutting fluid has on product quality and aerosol generation in the wet and dry turning of gray cast iron. To compare costs in wet and dry turning, a cost model, which includes cutting fluid-related components, has also been established.

In terms of manufacturing processes and systems, decision-makers may encounter difficulty in making environmentally friendly choices. This difficulty arises largely because of the nascency of environmentally responsible manufacturing. There is a sparsity of environmental information on processes and a variety of seemingly unconnected tools, methods, concepts, etc. To help decisions-makers understand the nature of a process and identify the appropriate tools/methods that may be most suited to reducing environmental impact, a classification system for manufacturing processes is established. Methods and tools for environmentally responsible manufacturing are then identified for each class. Two examples are presented to show how the new classification system may be applied in environmentally responsible manufacturing.

The techniques used to characterize the chemical and physical nature of particulates in diesel exhaust emissions are reviewed. The emphasis is on understanding the broader aspects of the fundamental nature of not only diesel particulates, but particulate systems in general. Consideration is given to the special nature of particulates which make them significant pollutants and to the relative place of the diesel in the formation of man-made particles. The underlying combustion processes leading to carbon and sulfur based particulates are reviewed. The important variables in steps of the combustion processes which lead to particulate formation are considered, as well as major fuel and engine factors. Collection methods are examined with examples given from current diesel dilution techniques. Probes, sampling lines, and instrumentation are considered.

The U.S. Bureau of Mines and Michigan Technological University are collaborating to conduct laboratory evaluations of oxidation catalytic converters (OCCs) and diesel fuels to identify combinations which minimize potentially harmful emissions. The purpose is to provide technical information concerning diesel exhaust emission control to the mining industry, regulators, and vendors of fuel and emission control devices. In this study, an Engelhard PTX 10 DVC (Ultra-10)* OCC was evaluated in the exhaust stream of an indirect injection Caterpillar 3304 PCNA mining engine using a light-duty laboratory transient cycle. This cycle was selected because it causes high emissions of particle-associated organics. Results are also reported for two different fuels with similar sulfur contents (0.03-0.04 wt pct) and a cetane number of 53, but different aromatic contents (11 vs. 20 wt pct).

This study was conducted to assess the effects of a low sulfur (<0.05 wt.%) fuel and an uncatalyzed ceramic particle trap on heavy-duty diesel emissions during both steady-state operation and during periods of electrically assisted trap regeneration. A Cummins LTA10-300 engine was operated at two steady-state modes with and without the trap. The exhaust trap system included a Corning EX-54 trap with an electrically assisted regeneration system. Both regulated emissions (oxides of nitrogen - NOx, total hydrocarbons - HC, and total particulate matter - TPM) and some unregulated emissions (polynuclear aromatic hydrocarbons - PAH soluble organic fraction - SOF, sulfates, vapor phase organics, and mutagenic activity) were measured during baseline, trap, and regeneration conditions. Emissions were collected with low sulfur (0.01 wt.%) fuel and compared to emissions with a conventional sulfur (0.32 wt.%) fuel. These fuels also varied in other fuel properties.

A review of mine air pollutant standards and the important pollutants to control in underground mines using diesel powered equipment is presented. The underground Mine Air Quality Laboratory instrumentation is discussed. This includes the Mine Air Monitoring Laboratory (MAML) and the instrumented Load Haul Dump (LHD) vehicle. The MAML measures CO, NO2, NO, CO2, particulate and temperatures while the LHD instrumentation measures and records engine speed, rack position (fuel rate), vehicle speed, CO2 concentration, exhaust temperature and operating mode with transducers and a Sea Data Corporation data logging and reader system. The mine LHD cycle data are related to the EPA 13 mode cycle data. Engine and aftertreatment emission control methods are reviewed including recent laboratory NO, NO2, sulfate and particulate data for a monolith catalyst. Maintenance of the LHD vehicle by engine subsystems in relation to component effects on emissions is presented.

Exhaust gas recirculation (EGR) has been employed in a diesel engine to reduce NOx emissions by diluting the fresh air charge with gases composed of primarily N2, CO2, H2O, and O2 from the engines exhaust stream. The addition of EGR reduces the production of NOx by lowering the peak cylinder gas temperature and reducing the concentration of O2 molecules, both of which contribute to the NOx formation mechanism. The amount of EGR has been typically controlled using an open loop control strategy where the flow of EGR was calibrated to the engine speed and load and controlled by the combination of an EGR valve and the ratio of the boost and exhaust back pressures. When oxygenated biofuels with lower specific energy are used, the engine control unit (ECU) will demand a higher fuel rate to maintain power output, which can alter the volumetric flow rate of EGR. In addition, oxygenated biofuels affect the oxygen concentration in the intake manifold gas stream.

A diesel oxidation catalyst (Engelhard PTX Series) was evaluated on a medium-duty diesel engine (Caterpillar 3208, naturally aspirated, direct injection). Tests were conducted at six modes of the EPA 13 mode heavy-duty cycle to measure the total particulate, soluble organic fraction (SOF), sulfates, NO, NO2, NOx and hydrocarbons emitted by the engine with and without the oxidation catalysts. Chemical analysis of the SOF collected was carried out to determine the effects of the catalysts on each of the subfractions composing the SOF. The Ames Salmonella/microsome bioassay was employed to quantify the mutagenic properties of the particulate SOF. Test results show large increases in the amounts of total particulate and sulfate emissions due to the catalyst while the amounts of SOF are reduced by the catalyst. The amounts of NOx produced with and without the catalyst are similar, but the equivalent NO2 emitted with the catalyst installed is increased at most modes.

A study of the Corning ceramic diesel particulate trap was conducted to investigate the trap's overall effect on diesel particulate fractions (soluble organic fraction. SOF; solid fraction, SOL; and sulfate fraction. SO4) under four different engine loads at 1680 rpm. The trap was found to filter the SOL fraction most efficiently with the SOF and SO4 fraction following in respective order. The filter efficiency of all fractions increased with increasing engine load. Graphs illustrating filter efficiency versus engine load indicate the slope of the SOF filter efficiency was smaller in magnitude than the TPM and SOL and SO4, fractions, which had similar slopes. The different slope of the SOF filter efficiency indicates other influences may be involved with the reduction in the SOF through the trap. Particle size distribution measurements in diluted exhaust revealed particle formation downstream of the trap.

Diesel exhaust particle size distributions were measured using an Electrical Aerosol Analyzer (EAA) with both conventional (0.31 wt. pet sulfur) and low sulfur fuel (0.01 wt pet sulfur) with and without a ceramic diesel particle filter (DPF). The engine used for this study was a 1988 heavy-duty diesel engine (Cummins LTA10-300) operated at EPA steady-state modes 9 and 11. The particle size distribution results indicated the typical bi-modal distribution; however, there were clear differences in the number of particles in each mode for all conditions. For the baseline conditions with no DPF, there was more than one order of magnitude greater number of particles in the nuclei mode for the conventional fuel as compared to the low sulfur fuel, while the accumulation modes for each fuel were nearly identical.

The objective of this research was to obtain diesel particle size distributions from a 1988 and a 1991 diesel engine using three different fuels and two exhaust control technologies (a ceramic particle trap and an oxidation catalytic converter). The particle size distributions from both engines were used to develop models to estimate the composition of the individual size particles. Nucleation theory of the H2O and H2SO4 vapor is used to predict when nuclei-mode particles will form in the dilution tunnel. Combining the theory with the experimental data, the conditions necessary in the dilution tunnel for particle formation are predicted. The paper also contains a discussion on the differences between the 1988 and 1991 engine's particle size distributions. The results indicated that nuclei mode particles (0.0075-0.046 μm) are formed in the dilution tunnel and consist of more than 80% H2O-H2SO4 particles when using the 1988 engine and 0.29 wt% sulfur fuel.

Formation of pollutants from diesel combustion and methods for their control have been reviewed. Of these methods, fuel injection rate and timing were selected for a parametric study relative to total particulate, soluble organic fraction (SOF), sulfates, solids and NO and NO2 emissions from a heavy-duty, turbocharged, after-cooled, direct-injection (DI) diesel. Chemical analyses of the SOF were performed at selected engine conditions to determine the effects of injection rate and timing on each of the eight chemical subfractions comprising the SOF. Biological character of the SOF was determined using the Ames Salmonella/microsome bioassay.

In sheet metal forming, metal flow into the die is determined by the restraint imposed by both the blankholder force and the drawbead penetration. This paper describes an experimental investigation in which both advanced binder force and drawbead technologies are used to study their effect on draw depth in the drawing of an AA6111-T4 generic non-symmetric panel. Multipoint binder loading using individual pin force adjustment applied to especially designed binder structures as well as the use of variable blankholder force were investigated in one laboratory in Germany. In another laboratory in the USA, active drawbeads were applied to the drawing of the generic panel. The results of both approaches, which are shown to be successful, are presented and discussed.

This paper is concerned with the demonstration of a methodology for chemically characterizing diesel particulate organic matter (POM) emissions. The procedure begins with a Soxhlet extraction of the POM with dichloromethane to obtain a soluble organic fraction (SOF). The acidic and basic portions of the SOF are isolated by liquid-liquid extraction techniques with aqueous base and aqueous acid, respectively. The neutral portion of the extract is separated into paraffin, aromatic, transitional and oxygenated fractions by column chromatography on silica gel. Two additional fractions, the ether insoluble and hexane insoluble fractions, are also separated by the procedure. Quantitative mass data are presented on the extraction and fractionation of twelve particulate samples from the exhaust of a medium-duty diesel engine collected in a dilution tunnel at a volume dilution ratio of 8 to 1.

One of the more objectionable aspects of the use of diesel engines has been the emission of particulate matter. A literature review of combustion flames, theoretical calculations and dilution tunnel experiments have been performed to elucidate the chemical and physical processes involved in the formation of diesel particulate matter. A comparative dilution tunnel study of diluted and undiluted total particulate data provided evidence supporting calculations that indicate hydro-carbon condensation should occur in the tunnel at low exhaust temperatures. The sample collection system for the measurement of total particulate matter and soluble sulfate in particulate matter on the EPA 13 mode cycle is presented. A method to correct for hydrocarbon interferences in the EPA barium chloranilate method for the determination of sulfate in particulate matter is discussed.

The objective in this research is to investigate the effects of variable blank holder force (VBHF) on the material formability, due to its effect on the strain path. It is found in a recent study [9] that VBHF does not significantly affect the overall trend of the strain path. This strain path in deep drawing process is linear for the materials in the flange and under punch face, and is roughly bi-linear for the material around the punch nose. The second segment of the strain path in the punch nose region is plane-strain. VBHF, however, affects the strain ratio ρ1 = ε2/ε1 of the first segment of the bi-linear strain path. These effects, especially ρ1, on limit strain were studied using M-K method. A strain path dependent modified forming limit diagram (MFLD) was calculated based on the actual strain path. It is found that the MFLD is strongly dependent on ρ1.

Diesel particulate trap regeneration is a complex process involving the interaction of phenomena at several scales. A hierarchy of models for the relevant physicochemical processes at the different scales of the problem (porous wall, filter channel, entire trap) is employed to obtain a rigorous description of the process in a multidimensional context. The final model structure is validated against experiments, resulting in a powerful tool for the computer-aided study of the regeneration behavior. In the present work we employ this tool to address the effect of various spatial non-uniformities on the regeneration characteristics of diesel particulate traps. Non-uniformities may include radial variations of flow, temperature and particulate concentration at the filter inlet, as well as variations of particulate loading. In addition, we study the influence of the distribution of catalytic activity along the filter wall.

The current trend in the automotive industry is to minimize/eliminate cutting fluid use in most machining operations. Research is required prior to achieving dry or semi-dry machining. Issues such as heat generation and transfer, thermal deformation and fluid lubricity related effects on tool life and surface roughness determine the feasibility of dry machining. This paper discusses recent advances in achieving dry/semi-dry machining. As the first step, research has been conducted to investigate the actual role of fluids (if any) in various machining operations. A predictive heat generation model for orthogonal cutting of visco-plastic material was created. A control volume approach allowed development of a thermal model for convective heat transfer during machining. The heat transfer performance of an air jet in dry machining was explored. The influence of machining process variables and cutting fluid presence on chip morphology was investigated through designed experiments.

A modified version of the Laminar and Turbulent Characteristic Time combustion model and the Hiroyasu-Magnussen soot model have been implemented in the flow solver Star-CD. Combustion simulations of three DI diesel engines, utilizing the standard k-ε turbulence model and a modified version of the RNG k-ε turbulence model, have been performed and evaluated with respect to combustion performance and emissions. Adjustments of the turbulent characteristic combustion time coefficient, which were necessary to match the experimental cylinder peak pressures of the different engines, have been justified in terms of non-equilibrium turbulence considerations. The results confirm the existence of a correlation between the integral length scale and the turbulent time scale. This correlation can be used to predict the combustion time scale in different engines.

In the automotive industry, lost foam casting is a relatively new technology, which is gaining popularity among manufacturers. Lost foam casting is a process in which an expanded polystyrene pattern is formed into the shape of the part to be cast. More complex parts are fabricated by simply gluing several simple patterns together. The pattern is then coated with a refractory material consisting of a mineral mixture and binders. Finally, hot metal is poured into the pattern, evaporating the expanded polystyrene and taking shape of the coating shell. However, the automotive industry has observed that a significant number of these fabricated, coated patterns are damaged, or do not meet specifications prior to casting. These are not reusable and inevitably are landfilled. It is the goal of this project to develop a simple, reliable, and inexpensive technology to recover expanded polystyrene from the glue and coating constituents.