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This paper, confined to the application of hard chrome plated liners to high-speed four-stroke diesel and gasoline engines, illustrates the increase in their popularity in the United Kingdom, and the advanced production methods which make this economically possible. The need for balanced engine life has long been apparent and is even more important today, the growth of motor transport having outstripped repair facilities. Iron bore life has been surpassed by improvement in the life of other component parts in the modern diesel engine. The provision of hard chrome plated liners can restore the balance. Further development and turbocharging of diesel engines has shown the need for a bore material capable of preventing scuffing and galling at elevated temperatures. Hard chrome has already proved itself in four-stroke engines under these conditions.

Ammonia is one of the most useful compounds that react with NOx selectively on a catalyst, such as V2O5-TiO2, under oxygen containing exhaust gas. However ammonia cannot be stored because of its toxicity for the small power generator in populated areas or for the diesel vehicles. A new concept for NOx reduction in diesel engine using ammonia is introduced. This system is constructed from the hydrogen generator by fuel reformer, the ammonia synthesizer, SCR catalyst for NOx reduction and the gas injection system of reformed gas into the cylinder. Experimental results show that, the SCR catalyst provides a very high rate of NOx reduction, reformed gas injection into cylinder is very effective for particulate reduction. WHEN CONSIDERING INTERNAL COMBUSTION ENGINES of the 1990's the question of how to harmonize the engine with the natural environments is one of the greatest problems. The internal combustion engine changes a substance into energy via its explosive combustion.

Powertrain electrification is becoming increasingly common in the transportation sector to address the challenges of global warming and deteriorating air quality. This paper introduces a novel “Build Your Hybrid” approach to experience and test various hybrid powertrain concepts. This approach is applied to the light commercial vehicles (LCV) segment due to the attractive combination of a Diesel engine and a partly electrified powertrain. For this purpose, a demonstrator vehicle has been set up with a flexible P02 hybrid topology and a prototype Hybrid Control Unit (HCU). Based on user input, the HCU software modifies the control functions and simulation models to emulate different sub-topologies and levels of hybridization in the demonstrator vehicle. Three powertrain concepts are considered for LCVs: HV P2, 48V P2 and 48V P0 hybrid. Dedicated hybrid control strategies are developed to take full advantage of the synergies of the electrical system and reduce CO2 and NOx emissions.

A new method for the structural study of long hydraulic cylinders has been developed. The rational analysis, taking cognizance of most known conditions and disturbances, is capable of an iterative type solution by computer. Some examples of its use are given, illustrating the effects of stroke length and mounting position on stresses, deflections, internal bearing loads, and critical axial load.

This paper discusses the use of electromechanical devices as the kinematic portions of a microprocessor based gas turbine control system. Specific applications are: 1. An electric motor driven, positive displacement pump, which provides metered high pressure fuel to the distribution manifold. Fuel metering to be provided by varying the motor angular velocity. 2. An electric motor driven lube oil pump. 3. Electromechnical actuators for motion and control of compressor and power turbine variable geometry. 4. A starter/generator integral with the gas generator. Topics covered include: Comparison to conventional hydro-mechanical systems. Response characteristics of the fuel pump and actuator systems. Brushless D.C. motor characteristics. Power electronics requirements for brushless D.C. motors. Control electronics interface with brushless D.C. motor systems. Reliability and maintainability issues. Diagnostic/prognostic enhancements.

Dynamic skip fire (DSF) has shown significant fuel economy improvement potential via reduction of pumping losses that generally affect throttled spark-ignition (SI) engines. In DSF operation, individual cylinders are fired on-demand near peak efficiency to satisfy driver torque demand. For vehicles with a downsized-boosted 4-cylinder engine, DSF can reduce fuel consumption by 8% in the WLTC (Class 3) drive cycle. The relatively low cost of cylinder deactivation hardware further improves the production value of DSF. Lean burn strategies in gasoline engines have also demonstrated significant fuel efficiency gains resulting from reduced pumping losses and improved thermodynamic characteristics, such as higher specific heat ratio and lower heat losses. Fuel-air mixture stratification is generally required to achieve stable combustion at low loads.

RADIOTRACERS were used to study the wear effects of engine speed, load, jacket water temperature, fuel temperature, and chromium-plated rings in a medium-speed diesel engine. One distillate fuel and two residual fuels were tested. This paper describes the tests and their results. Some of the conclusions are: The brake thermal efficiency with high viscosity residual fuel was essentially equal to distillate diesel fuel over a wide range of loads, providing the residual fuel was heated to the proper temperature. Engine speed did not affect the wear rate of cast-iron rings when distillate fuel was used, while with residual fuel wear decreased with increased speed. With distillate fuel, engine load had essentially no effect on cast-iron ring wear. With residual fuel, decreasing engine load produced a marked increase in ring wear*

COMPARISON of work capacity per unit mass and volume of different energy carriers shows that liquid hydrocarbons are superior to other energy sources. Solar and nuclear powerplants as well as their use in conjunction with a steam engine are examined in this paper. Suitability of an electric drive is discussed. Using a production 2-stroke diesel engine and its development forecast, a comparison is made of spark ignition, diesel, and gas turbine engines. The status of the free-piston engine turbine combination is reviewed.

SIMULTANEOUS RECORDINGS of cylinder pressure, audible sound, and crankshaft motion have shown that rumble is a noise associated with bending vibrations of the crankshaft. The vibrations are caused by abnormally high rates of pressure rise near the top dead center piston position. In this study the high rates of pressure rise were obtained by inducting deposits into the the engine. Thud is a torsional vibration of the crankshaft, similar in sound to rumble but resulting from much earlier occurrence of the maximum rates of pressure rise. Rumble vibrations consisted of a fundamental frequency of 600 cps and higher harmonics in the 11/1 compression ratio V-8 laboratory engine used in the investigation. The audible noise of rumble was predominantly composed of the second harmonic or about 1200 cps.

PEARLITIC malleable iron crankshafts are being used in the new Pontiac engine as a result of recent developments. This paper discusses the physical properties of pearlitic malleable iron such as elastic modulus, fatigue endurance, and tensile strength. According to the author, definite machining economies result from using pearlitic malleable iron crankshafts.

This paper deals with the Coupled thermo mechanical analysis of a cylinder head, cylinder block and crank case with the liner of an uprated engine. The existing engine develops 780 hp output with mechanical driven supercharger and the engine is uprated to 1000 hp by replacing the supercharger with a turbocharger and new Fuel injection equipment. For uprating any engine, the piston and cylinder head are the most vulnerable members due to increased mechanical and thermal loadings. Mechanical loading is due to the gas pressure in the gas chamber and its magnitude can be judged in terms of peak pressure. Thermal loading is due to temperature and the heat transfer conditions in the piston surface, cylinder liner and the cylinder head. The relative importance of the various loads applied on the head and cylinder block in operation are assessed and a method of predicting their influence on the structural integrity of the components described.

mDSF is a novel cylinder deactivation technology developed at Tula Technology, which combines the torque control of Dynamic Skip Fire (DSF) with Miller cycle engines to optimize fuel efficiency at minimal cost. mDSF employs a valvetrain with variable valve lift plus deactivation and novel control algorithms founded on Tula’s proven DSF technology. This allows cylinders to dynamically alternate among 3 potential states: high-charge fire, low-charge fire, and skip (deactivation). The low-charge fire state is achieved through an aggressive Miller cycle with Early Intake Valve Closing (EIVC). The three operating states in mDSF can be used to simultaneously optimize engine efficiency and driveline vibrations. Acceleration performance is retained using the all-cylinder, high-charge firing mode.

ENGINE noise has become an increasing problem with the higher and higher compression ratios of present-day automotive engines. Because fuel octane number cannot be raised indefinitely, the problem is one of engine design and selection of crankcase lubricating oils and gasoline formulations, the authors think. This paper describes investigations into the cause of spark knock, wild ping, rumble, and the added problem of hot-spot surface ignition (which also intensifies as compression ratios increase). The authors have found gasolines with phosphorous additives, used with properly formulated multiviscosity lubricating oils, provide a partial answer to the problem of engine rumble. The authors conclude that very exact tailoring of fuels, lubricants, additives, and engines will be necessary to prevent engine noise if compression ratios continue to rise.

THE NEW DIRECT-INJECTION diesel engines — the naturally aspirated 16000 and the turbocharged 21000 — were developed to power specific crawler and wheel vehicles built by Allis-Chalmers. Thus the original design and performance specifications were defined by the space available in these machines, and by the power and torque characteristics required by them. Also, the engines had to be suitable not only for commercial applications such as generator sets, shovels, and compressors, but also for oil field and marine service. Torque and speed requirements indicated that a 5¼-in. bore and 6½-in. stroke would give the desired performance. To meet the low heat rejection and good starting requirements, an open-chamber combustion system had to be used. The three-valve arrangement — two intake and one exhaust — was chosen because it offered low pumping losses and reasonable cost. This paper describes the design considerations and development work which produced the new diesel engines.*

THE performance characteristics of various devices applicable for jet directional control, lift augmentation, and VTOL-STOL studied at the NACA Lewis Laboratory are discussed, including jet deflection devices applicable to the conventonal round nozzle and novel nozzle configurations. The results indicate that many of the deflection devices applicable to conventional nozzles can readily be used for directional control or lift augmentation. Other deflection devices, such as movable plug, internal flap, cylindrical thrust reverser, swiveled primary with fixed shroud, and 90 deg side-bleed nozzle, are limited in application to jet directional control or aircraft trim because the loss in axial thrust for a given deflection force is prohibitive or the maximum deflected force obtainable is limited.

ALTHOUGH turbocharging of low-speed diesel engines has been used world-wide for a long time, it is only during recent years that it has been applied to high-speed diesels. This is the result of considerable engineering efforts from both the turbocharger and the diesel side that were put into the turbocharger, which appears to be a so utterly simple device. This paper de­scribes some of these engineering efforts. The basic design characteristics are developed with the point of view in mind that the turbo­charger has become much more than just an ad­ditional accessory. It is a vital component of the basic engine itself, contributing actively to the advancement of this prime mover. The basic de­sign characteristics center heavily around aero­dynamical and thermodynamical performance cri­teria which are so important in any advanced high-speed turbomachine.

Reduced emissions, improved fuel economy, and improved performance are a priority for manufacturers of internal combustion engines. However, these three goals are normally interrelated and difficult to optimize simultaneously. Studying the experimental heat release provides a useful tool for combustion optimization. Heavy-duty diesel engines are inherently transient, even during steady state operation engine controls can vary due to exhaust gas recirculation (EGR) or aftertreatment requirements. This paper examines the heat release and the derived combustion characteristics during steady state and transient operation for a 1992 DDC series 60 engine and a 2004 Cummins ISM 370 engine. In-cylinder pressure was collected during repeat steady state SET and the heavy-duty transient FTP test cycles.