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Technical Paper


After a brief consideration of airplane-engine practice in France, England and Germany, the author outlines the problems encountered in designing a twelve-cylinder aviation engine. He explains at some length the difficulties in determining the connection between propeller and engine and shows why valve-in-head location was chosen. Such features of engine design as the mounting of carbureter and exhaust pipes, methods of fuel and lubricant supply and details involved in selecting the lighting, starting and ignition equipment are considered.
Technical Paper


As the engine is the most important unit of a complete automobile chassis, it has had a major share of attention in its development and is far in advance of the rest of the machine as a result. Consequently, at least for the passenger-car engineer, improvements in the automobile as a road vehicle offer greater scope and reward than improvements in engines, particularly as all such improvements are reflected in direct proportion instead of being minimized by adverse operating conditions. The attitude has been common of not worrying about a fraction of 1-per cent loss here and there when such an enormous loss occurs at the exhaust pipe and radiator. Other varying and intermittent losses in the aggregate are not insignificant and, when multiplied by millions of cars, become millions of gallons of fuel and oil. The author's aim is to call attention to some of these losses, with suggestions as to means and methods of correction.
Technical Paper


New evidence is presented that wall quenching is the principal cause of the failure of all the fuel to burn in the combustion chamber. Moreover, it is shown that a significant portion of the quenched hydrocarbons are not exhausted from the engine cylinder. The hydrocarbon concentration of the gases which are exhausted from the chamber varies with time during the exhaust stroke. In addition, some of the quenched hydrocarbons may burn in the exhaust pipe. These findings provided a basis for enumerating several factors which ultimately determine the amount of hydrocarbons which reach the atmosphere.
Technical Paper

Development of a Three Wheeler Engine With LPG fuel For Improved Performance Using Simulation Techniques

Three-wheeler is a popular mode of transport in developing nations. Customers demand higher fuel economy from the vehicles to keep the operating costs to a minimum. Competitive environment of automobile market demands for new improved products with minimum development time. Computer simulations are very useful in reducing the development time through virtual prototyping and testing the system on computers rather than making the physical prototypes and testing on road. Particularly, lumped parameter modeling provides reasonably accurate results for predicting vehicle performance characteristics in short span of time. This is very useful when various system level targets have to be achieved and when trade-offs have to be made to obtain optimal results. This paper focuses on the development of a three-wheeler with LPG fuelled engine to achieve target performance using simulation tools.
Journal Article

Diesel Exhaust Aerosol Measurements Using Air-Ejector and Porous Wall Dilution Techniques

The objective of this work is to improve the understanding of variables like dilution and sampling conditions that contribute to particle-based emission measurements by assessing and comparing the nucleation tendency of diesel aerosols when diluted with a porous wall dilutor or an air ejector in a laboratory setting. An air-ejector dilutor and typical dilution conditions were used to establish the baseline sensitivity to dilution conditions for the given engine operating condition. A porous tube dilutor was designed and special attention was given to integrating the dilutor with the exhaust pipe and residence time chamber. Results from this system were compared with the ejector dilutor. Exhaust aerosols were generated by a Deere 4045 diesel engine running at low speed (1400 rpm) and low load (50 Nm, ~10% of rated). Primary dilution parameters that were varied included dilution air temperature (25 and 47°C) and dilution ratio (5, 14, and 55).
Journal Article

Motor Vehicle PM Emissions Measurement at LEV III Levels

This paper examines the issues concerning particulate matter (PM) emissions measurement at the 3 mg/mi level proposed as the future LEV III standard. These issues are general in nature, but are exacerbated at the low levels contemplated for upcoming emissions standards. They are discussed in the context of gasoline direct injection (GDI) engines, where they can have an important impact on the continued development of this technology for improved fuel economy. GDI particulate emissions, just as engine-out diesel PM, contain a high fraction of soot. But the total PM mass is significantly lower than from diesel engines, and there can be significant variations in emissions rate and apparent PM composition between cold-start and running emissions. PM emissions levels depend on sampling method and location. As a result, there can be substantial differences in PM sampled and diluted directly at the exhaust pipe, as opposed to measurements from a dilution tunnel.
Technical Paper

Optimizing the On Board Diagnostic System (OBD) to Monitor for Reduction of the SCR Catalyst Conversion Efficiency using the NOx Sensor

Due to the independent operation of the aftertreatment system from the engine, the aim of the OBD system (On Board Diagnostic) is to guarantee the powertrain emissions stay within the emissions standards during all the vehicle useful life. In the case of heavy-duty diesel vehicles, that uses the SCR system (Selective Catalytic Reduction) as the aftertreatment technology to meet the stringent emissions levels, the use of a NOx sensor in the exhaust pipe will be indispensable for a reliable monitoring of the emissions. Analyzing the European directives that are legislating the OBD system, the NOx sensor must be monitored by the emissions control system, guaranteeing faults detection in the aftertreatment system that could increase the emissions. According to the annex 4 of the directive 2005/78/EC item (requirements for the OBD system Stage 2), it is needed to monitor the catalyst efficiency as an isolated component of the system.
Technical Paper

A Study on the Factors Affecting Heated Wall Impinging Characteristics of SCR Spray

Many studies show that under diesel engine operating conditions, SCR reductant sprays will impinge on the wall of exhaust pipes. In order to understand this impinging process of SCR reductant spray, and to analyze what factors affect it, a test bench was set up by means of high speed video camera. At atmospheric pressure, SCR spray was injected on a heated metal wall, the impacts of wall temperature, injection pressure, injection height and angle on developing characteristics of SCR reductant spray after impinging on the heated wall have been researched and analyzed. The results show that the heated wall temperature has a great impact on the spray developing process, when wall temperature is lower than 405K, after water evaporated the crystallized urea will remain on the wall to block exhaust pipes. When wall temperature is higher, the atomization and evaporation of SCR reductant spray will be better, and the hydrolysis process of urea will be faster.
Technical Paper

Modeling of the Injection and Decomposition Processes of Urea-Water-Solution Spray in Automotive SCR Systems

The current work aims to develop a reliable numerical model simulating the depletion and decomposition process of urea-water solution (UWS) droplets injected in a hot exhaust stream as experienced in an automotive urea-based selective catalytic reduction (SCR) system. The depleting process of individual UWS droplets in heated environment is simulated using a multicomponent vaporization model with separate depletion law for each component. While water depletion is modeled as a vaporization process, urea depletion from the UWS droplet is modeled using two different approaches. The first approach models urea depletion as a vaporization process with an experimentally determined saturation pressure. The second approach models urea depletion as a direct thermolysis process from molten urea to ammonia and isocyanic acid using various sets of kinetic parameters. Comparison with experimental data shows the superiority of modeling urea depletion as a vaporization process.
Technical Paper

Effective BSFC and NOx Reduction on Super Clean Diesel of Heavy Duty Diesel Engine by High Boosting and High EGR Rate

Reduction of exhaust emissions and BSFC was studied for high pressure, wide range, and high EGR rates in a Super-clean Diesel six-cylinder heavy duty engine. The GVW 25-ton vehicle has 10.52 L engine displacement, with maximum power of 300 kW and maximum torque of 1842 Nm. The engine is equipped with high-pressure fuel injection of a 200 MPa level common-rail system. A variable geometry turbocharger (VGT) was newly designed. The maximum pressure ratio of the compressor is about twice that of the previous design: 2.5. Additionally, wide range and a high EGR rate are achieved by high pressure-loop EGR (HP-EGR) and low pressure-loop EGR (LP-EGR) with described VGT and high-pressure fuel injection. The HP-EGR can reduce NOx concentrations in the exhaust pipe, but the high EGR rate worsens smoke. The HP-EGR system layout has an important shortcoming: it has great differences of the intake EGR gas amount into each cylinder, worsens smoke.
Journal Article

Enhancement of Diesel Soot Combustion with Oxygen on Particulate Filters After Injection of Dicyclopentadienyl Iron (Ferrocene) in the Exhaust Pipe

For the regeneration of diesel particulate filters with oxygen, temperatures above 550°C are normally required. The increase of the exhaust gas temperature to temperatures above 500°C demands a large amount of energy, so that strategies to reduce the regeneration temperature have to be considered. One option is the injection of a catalyst, which reduces the required regeneration temperature. Hence, a system was developed at HJS Emission Technology GmbH to inject catalyst-precursor into the exhaust gas pipe, whereby the catalysts are generated due to decomposition of the precursor in the hot exhaust gas. A technique based on the calculation of apparent activation energies was developed to characterize the soot combustion on the filter. In the first step metal oxide catalysts, like cerium(IV)oxide, manganese-oxide and iron(III)oxide were investigated after injection of their nitrate precursors dissolved in water.
Technical Paper

The Regeneration of Diesel Particulates Filter (DPF) with Hydrogen

Diesel engines possess high energy efficiency as for power generation, and they have been used in commercial vehicles widely for a long time. Due to the coming shortage of fossil fuel in the near future and the impact of greenhouse gas effect in recent years, the types and quantities of diesel vehicles have grown year by year. However, smoke emission of diesel engine has always been an issue. Diesel smoke can be seen by eyes apparently, and it becomes an obvious pollution problem. Traditional diesel particulate filter (DPF) is the current solution to solve the problem of smoke emission currently. However, after using DPF for a certain period of time, the back pressure of engine will rise up and the engine performance will be affected because of the accumulation of soot particles. The soot particles must be removed. This process is the regeneration of DPF.
Technical Paper

New Challenges and Technologies for the Emissions Monitoring System (OBD) in Heavy Duty Diesel Engines to Meet the Requirements of the PROCONVE P7

Due to the independent operation between the aftertreatment systems and the engine, the aim of the On Board Diagnostic System (OBD) is to ensure the engine emissions stay within the emissions standards during the whole vehicle useful life. In the case of the heavy duty diesel vehicles that use the Selective Catalytic Reduction System (SCR) or the Exhaust Gas Recirculation System (EGR) as the NOx aftertreatment technologies to meet the stringent emissions levels, the use of sensors in the exhaust pipe is required to control and to monitor the engine emissions. These are new and great challenges to the national diesel engine developers who are working with these systems to get the homologation certification. Accurate mathematic models within the automotive control strategies are becoming ever more important and are strongly used to monitor the NOx emissions directly (in case of SCR systems using the NOx sensor) or indirectly (in case of EGR systems using the Lambda sensor).
Technical Paper

The Fluid Induced Vibration Analysis on an Integrated Exhaust Manifold

With its advantages on cost and performance, the integrated exhaust manifold (casting with the turbine) is being used on more vehicles by auto makers. Generally, when compared with the divided exhaust manifold, the integrated exhaust manifold stands for higher vibratory excitation from gas dynamics. In this paper, the gas dynamics excitation has been computed through the GD (gas dynamics) software GT-Power which calculates the exhaust pipe surface pressure, and CFD code Star-CCM+ which calculates the turbine blade force. And the response of manifold has been solved under this excitation. On the other hand, the mechanical excitation has been computed through the MBD (multi-body dynamics) platform AVL-Excite-PU, and the responses under the gas excitation plus the mechanical load have been studied in order to analyze the effects of the fluid excitation on an integrated manifold.
Journal Article

In-Situ Real-Time Fuel Consumption Measurement Using Raw Exhaust Flow Meter and Zirconia AFR Sensor

Fuel efficiency is one of the most important parameters in advanced vehicles. Therefore, the measurement of fuel consumption in-situ and in real-time is obviously demanded in development and evaluation processes of new engines and vehicles. This paper describes a new concept for measuring fuel consumption in real-time, which utilizing raw exhaust gas flow rate and exhaust air-to-fuel ratio (AFR). The AFR is defined as the mass ratio of air and fuel supplied to the engine, and the mass flow rate of exhaust gas can be regarded as the summation of the mass flow rate of air and fuel. This means the fuel consumption can be calculated from exhaust flow rate and AFR. To realize in-situ, real-time measurement, we used an ultrasonic exhaust flow meter which can measure a wide flow range accurately with no pressure loss, and a fast response zirconia sensor which can be installed onto the exhaust pipe directly without any sampling system.
Technical Paper

LES Multi-cycle Analysis of a High Performance GDI Engine

The paper reports the application of LES multi-cycle analysis for the characterization of cycle to cycle variability (hereafter CCV) of a highly downsized DISI engine for sport car applications. The analysis covers several subsequent engine cycles operating the engine at full load, peak power engine speed. Despite the chosen engine operation is usually considered relatively stable, relevant fluctuations were experimentally measured in terms of in-cylinder pressure evolution and combustion phasing. On one hand, despite the complex architecture of the V-8 engine, the origin of such CCV is considered to be poorly related to cyclic fluctuations of the gas-dynamics within the intake and exhaust pipes, since acquisitions of the instantaneous pressure traces at both the intake port entrance and exhaust port junction by fast-response pressure measurements over 250 subsequent engine cycles showed almost negligible differences in both amplitude and phasing compared to those within the cylinder.
Journal Article

Non Intrusive Exhaust Gas Heat Recovery System for an Automobile: A Preliminary Investigation

A parallel flow concentric tube heat exchanger is designed to recover exhaust heat by using the exhaust pipe as the tube side and the concentric tube as the shell side. The heat exchanger which is also called the primary heat exchanger is welded concentrically to the intermediate exhaust pipe forming a double pipe heat exchanger. The shell side pipe consists of Cold Water inlet and Hot Water outlet, while the tube side pipe carries the hot exhaust gases. The water flowing in the shell side gets heated due to conduction and convection and is circulated through the Hot Water outlet to produce Hot Water on demand. The same Hot Water is simultaneously circulated to the annular chamber of the secondary heat exchanger, thereby transferring the heat to the Hot Box.
Journal Article

Drivetrain Energy Distribution and Losses from Fuel to Wheel

Depending on a vehicles drive cycle, an improvement of the overall drivetrain efficiency does not necessarily have to go along with an improvement of its mileage. In here the ratio of energy to overcome rolling resistance, aerodynamic drag, acceleration and energy wasted directly in wheel brakes is responsible for potentially differing trends. A detailed knowledge of energy flows, sources and sinks makes up a substantial step into optimizing any drive train. Most fuel energy leaves the drivetrain via exhaust pipes. Next to usable mechanical energy, a big amount is spent to heat up the system directly or to overcome drive train friction, which is converted into heat to warm up the system additionally. An in depth quantification of the most important energy flows for an upper middle-sized class gasoline powered drive train is given as results of warm-up cycle simulations.
Technical Paper

Model Based Study of the Urea Injector's Effects on SCR of an 11 Liter Diesel Engine

Selective catalytic reduction (SCR) has become one of the primary technologies to reduce internal combustion engine (ICE) emission. The installation angle of urea injector plays an important role during the SCR process. The urea injector is often vertically mounted to the exhaust pipe for on road heavy duty truck because of its good performance and general packaging convenience, and this type of installation has been the focus of previous research. However, due to certain packaging constraints or responsiveness considerations, the injector is installed with an inclined acute angle to the exhaust pipe under some circumstance.
Technical Paper

Scope of Fe-ZSM5 Zeolite Based Urea-SCR with Fish Oil Bio-Diesel Fuel in Compressed Ignition Engine

The present consumption rates and heavy dependence on fossil fuels pose a humongous threat to the environment. The increased pollution in urban areas is already causing serious sociological, ecological and economic implications. The issue of energy security led governments and researchers to look for alternate means of renewable and environment friendly fuels. Biodiesel has been one of the promising, and economically viable alternatives. The biodiesels are reported to cause reduction in CO, HC and PM emissions. However, NOx emissions are increased in case of biodiesel in CI engine. Therefore, a Urea-SCR over Fe-ZSM5 honeycomb substrate (400cpsi) zeolite catalyst after treatment system is an effective technology to reduce emissions for biodiesel applications. Exhaust gases pass through the catalyst and reactions take place along its surface, consequently converting NOx into nitrogen and H2O.