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A new proprietary Atmospheric Pressure Microwave Plasma Technology, developed for various materials processing applications, has been applied to P/M sintering of cam lobes. The aims were a) to compare the new processing route with conventional process for the same alloy composition and b) to check the possibility of successful sintering at higher temperatures so that different higher temperature P/M alloys may be used. P/M green cam lobes were used, and sintering runs were carried out initially at temperatures comparable to that currently used in the conventional processes; this was followed by runs at higher temperatures that are not very practical in the conventional processing route due to equipment component constraints. Properties such as density and hardness were measured for the sintered samples, together with corresponding microstructural analysis.

Automotive parts have been brazed by heating with atmospheric pressure plasma generated by a computer controlled 2.45 GHz, 5 kW microwave source. The plasma is created in a suitable gas by a simple, proprietary ignition process and is confined to the vicinity of the joint, thereby eliminating thermal stress in other areas. Brazing of 1008 low-carbon steel parts with copper generates a distinctive spike in the plasma emission intensity at the time when copper melts. This spike can be used as a signature for brazing. The energy efficiency, test results, and the significance of the braze signature are discussed.

Microwave plasmas at atmospheric pressures can be utilized for carburization of steel alloys. Due to their high frequencies, microwaves ionize and dissociate molecules with great efficiency and provide carbon for carburization by dissociating hydrocarbons that are introduced in the plasma. Also, conventional carburization techniques are not very energy efficient, as much of the heat generated is not utilized for the heating of the parts. Microwave plasmas are highly energy efficient due to very high coupling of microwaves to the plasma and then transferring of heat to the parts. Since plasma surrounds the part uniformly, heating rates over the part surface are also uniform. Preliminary results are presented for carburization of steel alloy 8620H by atmospheric microwave plasma process using acetylene as the source gas. Possible effects of application of pulsed DC bias to the parts are also discussed.

The Euro IV/V emission standards for diesel passenger vehicles require a reduction in Carbon Monoxide (CO) and Hydrocarbon (HC) emissions that necessitates the use of an oxidation catalyst function for many of the applications. Field-aged catalysts were analyzed to determine their deactivation mechanisms. In this paper, it is shown that by proper selection of washcoat materials, the sulfur tolerance and performance characteristics of the DOC can be improved. It is also shown how the DOC and can be made to withstand the low temperature operation sulfur poisoning effect as well as high temperatures resulting from post-injection of fuel.

The fluid borne noise in the power steering system of an automobile can couple with the chassis vibrational modes to produce audible noise in the passenger compartment. If the pressure ripple produced by the power steering pump, which is the main source of fluid borne noise, is reduced, the automobiles can be made quieter. In this paper, an active, broadband (bandwidth ∼1 kHz) noise cancellation technique based on piezoelectric actuators is presented. A reduction in pressure ripple by a factor of up to five is observed in a EHPS system. The design of control electronics also presents some challenges. The restrictions and advantages of feedback electronics used are also discussed.

A new method of solution is presented for the equations governing unsteady flow field during compression and combustion in a spark ignition. The Lagrangian approach, an application of a vortex method to the three-dimensional solution of the continuity and conservation equations, avoids the need for a turbulence model and wall laws close to the surfaces. Vorticity is introduced as blobs close to the wall which diffuse into the main flow. The potential equation is solved by the boundary element method. Combustion is treated as a thin sheet propagating at laminar flame speed using an extension of the simple line interface method to three-dimensions, now called a simple plane interface method. The code is demonstrated in application to a wedge shaped combustion chamber with surface irregularities closely approximating the actual shape.

A methodology for predicting the cyclically variable pressure time history based on correlations derived from optically observed flame fronts in the engine is presented. The methodology relies on relating the observed flame propagation to engine design and operating parameters like swirl, engine speed and chamber geometry etc. The correlations are developed using typically 25 cycles of engine data for each operating condition. The cyclic variability is incorporated in the model by analyzing the observed variability in the flame kernels corresponding to 1% burnt mass. The pressure time history is predicted using a spherical flame front model. The model is able to predict both the pressure history and the cyclic-variation reasonably well.

A fleet of 17 utility, van and flat tray bodied trucks has been tested for fuel consumption and exhaust emissions over a range of drive cycles and steady state operating conditions. The influence of vehicle load on the results was included. For each vehicle the tractive force applied by the chassis dynamometer, on which testing was performed, was adjusted to match those found on the road using a new procedure. The fuel consumption results show a downward trend with model year (1.7% annum); about 30% higher petrol use compared with diesel; a cold start penalty of 3 L/100 km and over 2:1 variation for vehicles capable of identical transport task. Exhaust emissions from these rigid trucks were between 3 and 6 times greater than those of the passenger car fleet.

A thermodynamic model has been employed to study the effect of changing injection timing, spray angle, fuel density, fuel viscosity, chemical reaction rate constants and air entrainment on the combustion performance of seed oils and their methyl esters in an open chamber diesel engine. It is shown that the most important valuables affecting the performance are fuel density and fuel viscosity. It is deduced that modification of these physical properties can lead to substantial improvement in the combustion performance of the seed oils.

A study of the performance characteristics of Indolene-Methanol Plus High Alcohols (MPHA) has been completed. The study includes the measurement of fuel properties and performance parameters. The fuel properties investigated are distillation characteristics, heat of combustion, flash point, specific gravity and water tolerance. The performance parameters measured are MBT spark advance, power output and thermal efficiency. The alcohol concentration was varied from 0 to 100 percent by volume in clear indolene. The measurement of fuel properties indicated that, in general, MPHA-indolene blends have higher water tolerance, similar specific gravity, similar flash point and different distillation characteristics compared to methanol-indolene blends. The performance parameters were measured using a single cylinder CFR spark ignition engine at different compression ratios.

A phenomenological model having modular formulation is presented for combustion in the open chamber diesel engine. The modules for fuel injection, jet penetration and droplet formation have been calibrated outside the engine in a high pressure, fixed volume chamber by high speed photographic and laser analysis of single spray ‘shots’. In the diagnostic mode of operation the chemical components of the combustion reaction are estimated. In the predictive mode of operation the model is used to estimate engines’ pressure diagrams and various other combustion characteristics of the fuels over a wide range of speed and load conditions. Finally, sensitivity analyses of the reaction rate constants of five fuels namely distillate, sunflower oil, rapeseed oil and methyl esters of sunflower and rapeseed oils, to some of the model inputs are presented.