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The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken.

Abstract Due to the increasing requirements for efficiency, the wide range of characteristics and the improved possibilities of modern development and production processes, compressors in turbochargers have become more individualized in order to adapt to the requirements of internal combustion engines. An understanding of the working mechanisms as well as an understanding of the way that losses occur in the flow allows a reduced development effort during the optimization process. This article presents three-dimensional (3D) Computational Fluid Dynamics (CFD) investigations of the loss mechanisms and quantitative calculations of individual losses. The 3D-CFD method used in this article will reduce the drawbacks of one-dimensional calculation as far as possible. For example, the twist of the blades is taken into account and the “discrete” method is used for loss calculation instead of the “average” method.

The legislations on emission reduction is getting stringent everywhere in the world. India is following the same trend, with Government of India (GOI) declaring the nationwide implementation of BS 6 legislation by April 2020 and Real Driving Emission (RDE) Cycle relevant legislation by 2023. Additionally GOI is focusing on reduction of CO2 emissions by introduction of stringent fleet CO2 targets through CAFE regulation, making it mandatory for vehicle manufacturers to simultaneously work on gaseous emissions and CO2 emissions. Simultaneous NOx emission reduction and CO2 reduction measures are divergent in nature, but with a 48 V Diesel hybrid, this goal can be achieved. The study presented here involves arriving at the right future hybrid-powertrain layout for a Sports Utility Vehicle (SUV) in the Indian scenario to meet the future BS 6 and CAFÉ legislations. Diesel engines dominate the current LCV and SUV segments in India and the same trend can be expected to continue in future.

Abstract Regulations limiting GreenHouse Gases (GHG) from Heavy-Duty (HD) commercial vehicles in the United States (US) and European Union will phase in between the 2024 and 2030 model years. These mandates require efficiency improvements at both the engine and vehicle levels, with the most stringent reductions required in the heaviest vehicles used for long-haul applications. At the same time, a 90% reduction in oxides of nitrogen (NOx) will be required as part of new regulations from the California Air Resources Board. Any technologies applied to improve engine efficiency must therefore not come at the expense of increased NOx emissions. Research into advanced engine architectures and components has identified improved turbomachine efficiency as one of the largest potential contributors to engine efficiency improvement. However this comes at the cost of a reduced capability to drive high-pressure Exhaust Gas Recirculation (EGR).

By means of computer simulation, the potential of a Band Variable-Inertia Flywheel (BVIF) as an energy storage device for a diesel engine city bus is evaluated. Replacing both a fixed-inertia flywheel (FIF) and a continuously variable transmission (CVT), the BVIF is capable of accelerating a vehicle from rest to a nearly-constant speed, while recovering part of the kinetic energy normally dissipated through braking of the vehicle. The results are compared with that of conventionally-powered bus. A fuel saving of up to 30 percent is shown with the BVIF-integrated system. The regenerative braking system reduces brake wear by a factor of five in comparison with the conventional vehicle.

Parameters like brake mean effective pressure, mean velocity of the piston, hardness of the wear surface, oil film thickness, and surface areas of critical wear parts are similar for all the diesel engines. The mean piston velocity at the rated speed is nearly the same for all the diesel engines. The mechanical efficiency normalized to an arbitrary brake mean effective pressure (bmep) is dependent on the size of the engine. The engine life seems to be proportional directly to the square of a characteristic dimension namely, cylinder bore of the engine and inversely to speed and load factor for engines varying widely in sizes and ratings.

A quasi-dimensional computer simulation model is presented to simulate the thermodynamic and chemical processes occurring within a spark ignition engine during compression, combustion and expansion based upon the laws of thermodynamics and the theory of equilibrium. A two-zone combustion model, with a spherically expanding flame front originating from the spark location, is applied. The flame speed is calculated by the application of a turbulent entrainment propagation model. A simplified theory for the prediction of in-cylinder charge motion is proposed which calculates the mean turbulence intensity and scale at any time during the closed cycle. It is then used to describe both heat transfer and turbulent flame propagation. The model has been designed specifically for the two-stroke cycle engine and facilitates seven of the most common combustion chamber geometries. The fundamental theory is nevertheless applicable to any four-stroke cycle engine.

To meet future needs for heavy truck cooling, a novel high performance radial compact cooling system (CCS) was developed. Measurements with a prototype system were conducted in a component wind tunnel and with truck-installed systems in a climatic vehicular wind tunnel. The CSS is compared to conventional axial and side-by-side systems. In comparison with a conventional axial system, the performance per unit volume of the CCS is 42% higher, the noise level is about 6 dB lower and the power consumption of the radial fan is 70% of the axial fan leading to significant savings in fuel consumption.

Engine mounts are an integral part of the vehicle that helps in reducing the vibrations generated from the engine. Engine mounts require a simple yet complicated amalgamation of two very different materials, steel and rubber. Proper adhesion between the two is required to prevent any part failure. Therefore, it becomes important that a comprehensive study is done to understand the mating phenomenon of both. A good linking between rubber and metal substrate is governed by surface pretreatment. Various methodologies such as mechanical and chemical are adopted for the same. This paper aims to present a comparative study as to which surface pretreatment has an edge over other techniques in terms of separation force required to break the bonding between the two parts. The study also presents a cost comparison between the techniques so that the best possible technique can be put to use in the commercial vehicle industry.

Hundreds of millions of micromachined, piezoresistive Manifold Absolute Pressure (MAP) sensors have been produced to reduce pollution and improve fuel efficiency in engine control systems. Other vehicle applications for micromachined pressure sensors include monitoring turbo pressure, barometric pressure, fuel tank leakage, fuel rail pressure and tire pressure. Exhaust gas recirculation and even door compression for side impact detection are employing micromachined silicon pressure sensors. Piezoresistive pressure sensors have dominated the automotive market to date. Practical micromachined capacitive pressure sensors have recently been developed and could replace the piezoresistive sensor in many applications. This paper will examine the advantages of both pressure sensing technologies, and discuss applications that an inexpensive capacitive pressure sensor will open up.

Euro 6 emission norms are getting implemented in India from April 2020 and it is being viewed as one of the greatest challenges ever faced by the Indian automotive industry. In order to achieve such stringent emission norms a good strategy will be to optimize the engine out emission through in cylinder emission control techniques and a right sized after treatment system has to be used for this optimized engine. There exist several factors and trade-off between these should be established for in cylinder optimization of emissions. Since the turbocharger plays an apex role in controlling both the performance and engine out emissions of a CI engine, turbocharger selection is a crucial step in the development of new generation of Euro 6 engines in India. Such engines are equipped with additional actuators such as Intake Throttle Valve and Exhaust Throttle Valve and combination of these flap operations with turbocharger output plays a prominent role in controlling performance and emission.

Effects of included spray angle with different injection strategies on combustion characteristics, performance and amount of pollutant emission have been computationally investigated in a common rail heavy-duty DI diesel engine. The CFD model was firstly validated with experimental data achieved from a Caterpillar 3401 diesel engine for a conventional part load condition at 1600 rev/min. Three different included spray angles (α = 145°, 105°, 90°) were studied in comparison with the traditional spray injection angle (α = 125°). The results show that spray targeting is very effective for controlling the in-cylinder mixture distributions especially when it accompanied with various injection strategies. It was found that 105° spray cone angle along with an optimized split pre- and post-Top Dead Center (TDC) injection strategy could significantly reduce NOx and soot emissions without much penalty of the fuel consumption, as compared to the wide spray angle.

A Vehicle-Engine-Cooling (VEC) system computer simulation model was used to study the transient performance of control devices and their temperature settings on oil, coolant and cab temperatures. The truck used in the study was an International Harvester COF-9670 cab over chassis heavy-duty vehicle equipped with a standard cab heater, a Cummins NTC-350 diesel engine with a McCord radiator and standard cooling system components and aftercooler. Input data from several portions of a Columbus to Bloomington, Indiana route were used from the Vehicle Mission Simulation (VMS) program to determine engine and vehicle operating conditions for the VEC system computer simulation model. The control devices investigated were the standard thermostat, the Kysor fan-clutch and shutter system. The effect of shutterstat location on shutter performance along with thermostat, shutter and fan activation temperature settings were investigated for ambient temperatures of 32, 85 and 100°F.

This paper describes the simulation model of a backhoe excavator. The model uses a prescribed motion cycle and the objective of the program is to determine the power requirements for each of the cylinders as well as the total engine power requirement. Most computer simulations are developed by expressing the differential equations of motion for the system being studied. The known force inputs to the system are applied and the time response of the system is then obtained by numerically integrating the governing differential equations. This paper on the other hand develops the reverse of this. Utilizing a prescribed geometry and trajectory cycle for a linkage system as the input, the program solves for the types of force inputs that are required to achieve that trajectory. With the time dependence of the trajectory known, the total power required and the power required of each cylinder is also evaluated. A typical excavator linkage is shown in Fig. 1.

Water-cooled charge air cooling is being considered as part of various technology solutions in response to 2007 US, 2010 US, EU4 and EU5 emissions standards. As manufacturers determine appropriate engine and vehicle solutions to meet the upcoming emissions standards, charge air cooling requirements are increasing due to higher turbocharger outlet temperatures and pressures, higher EGR rates, and requests for intake manifold temperature control to manage combustion and exhaust temperatures. Valeo and EMP have collaborated on the development and testing of a water cooled charge air cooler (WCCAC), controlled by a 12 volt brushless motor coolant pump. The system design addresses material temperature limitations of air-air aluminum CAC's and has the potential to simplify the packaging of the air induction system.

In order to fulfill the technical requirements of a high-efficiency low-emissions off-road horizontal diesel engine, a unique design is proposed and optimized in this paper for the cooling water jacket structure with a forced-cooling closed-loop cooling system. The cooling water flow rate, temperature, and pressure at the inlet and several other critical locations of the cooling water jacket were measured and analyzed at different engine operating conditions for the water jacket designs. A numerical simulation model of the coolant flow and the cooling system was built and used to analyze the thermal/fluid characteristics of the coolant flow in the water jacket. The impact of different structural and packaging design parameters on coolant flow and heat transfer was investigated. The design deficiency of an original (earlier) design of the water jacket was pointed out and an improved design was proposed.

The absence of combustion information continues to be one of the key obstacles to the intelligent development of engines. Currently, the cost of integrating cylinder pressure sensors remains too high, prompting attention to methods for extracting combustion information from existing sensing data. Mean-value combustion models for engines are unable to capture changes of combustion parameters. Furthermore, the methods of reconstructing combustion information using sensor signals mainly depend on the working state of the sensors, and the reliability of reconstructed values is directly influenced by sensor malfunctions. Due to the concentration of operating conditions of hybrid vehicles, the reliability of priori calibration map has increased. Therefore, a combustion information reconstruction method based on priori calibration information and the fused feature deviations of existing sensing signals is proposed and named the "Deviation-based Centroid Displacement Method" (DCDM).

Several factors have driven the development of various electronic marine shift/throttle control systems in recent years. The benefits of marine electronic shift/throttle systems are increased cycle life, reduced maintenance requirements, and decreased installation concerns. Design considerations include selection of a microprocessor system, communication between nodes, operator feedback, and protocols for various mode selections. A recent development in marine electronic technology uses a distributed microprocessor approach that eliminates the negative factors associated with mechanical controls while actually improving operator feedback. The system's serial communication also allows for expansions into intelligent systems applications. This technology shows promise for use in industrial, automotive, and military applications.

The authors designed and produced a new dual fuel injector that allows two different kinds of fuel to be injected. This injector contains both a throttle type nozzle and a hole type which are located coaxially. The injection timing as well as the fuel quantity can be controlled individually. The running test using two lines of gas oil brought a good reduction of NOx and exhaust smoke. The experiment using gas oil and alcohol also brought a satisfactory reduction of exhaust emission.

We propose a novel dual-fuel combustion model for simulating heavy-duty engines with the G-Equation. Dual-Fuel combustion strategies in such engines features direct injection of a high-reactivity fuel into a lean, premixed chamber which has a high resistance to autoignition. Distinct combustion modes are present: the DI fuel auto-ignites following chemical ignition delay after spray vaporization and mixing; a reactive front is formed on its surroundings; it develops into a well-structured turbulent flame, which propagates within the premixed charge. Either direct chemistry or the flame-propagation approach (G- Equation), taken alone, do not produce accurate results. The proposed Dual-Fuel model decides what regions of the combustion chamber should be simulated with either approach, according to the local flame state; and acts as a “kernel” model for the G- Equation model. Direct chemistry is run in the regions where a premixed front is not present.