Engine Duty Cycle Research Articles

Enabling off-highway diesel engine downsizing and performance improvement using electrically assisted turbocharging

Internal combustion engine (ICE) downsizing through various turbocharging configurations is generally known by the powertrain design community as an effective means to reduce frictional losses, increase waste heat recovery, and improve fuel efficiency while increasing engine power density. However, often is the case that turbocharging strategies, including variable geometry turbochargers, and regulated two-stage turbochargers, incur the performance tradeoff between transient response and fuel economy (pumping losses) at high engine speeds. For off-highway vehicles having particularly transient and high-powered duty cycles, efforts to improve this tradeoff and increase operational flexibility have turned to evaluating various electrified air system architectures. In this study, a 4.5 L diesel-ICE configured with an electrically driven compressor (eBooster®) is placed in series with a conventional turbocharger and integrated into a 48 V mild-hybrid powertrain architecture. The objective of this powertrain configuration is to enable engine downsizing by 34%, replacing the current 6.8 L ICE platform with the hybridized 4.5 L ICE concept. The commercial 1-D simulation software GT-SUITE is used for powertrain system development and system optimization. Development and validation of the GT-SUITE model and air system controls is concurrently supported through experimental data collection. The simulation model development includes using machine learning methods for optimizing exhaust gas dilution, injection timing, and eBooster® power to improve steady-state and transient brake-specific fuel consumption while minimizing criteria pollutant emissions. It was found that total specific fluid consumption over the standardized non-road transient engine duty cycle could be reduced by 18% over the current 6.8 L engine by using an optimized eBoosted 4.5 L engine. The hybridized 4.5 L engine concept concurrently showed sufficient transient response capability and nearly an order of magnitude reduction in duty cycle total soot production.

Retrofit Micro Turbojet Engine AERO-16 Berbasis Turbocharge HOLSET HX-35

Gas turbine engine is a type of engine that performs internal combustion. The engine works by converting thermal energy into mechanical energy, where the thermal energy is generated from the combustion chamber and the mechanical energy is generated from the turbine rotation. This research discusses in detail the manufacturing process of the Micro Turbojet Engine Aero-16. Before manufacturing, a literature study is carried out and information gathering about what data needs to be prepared as a benchmark for manufacturing. The Micro Turbojet Engine Aero-16 has the main components in the form of a compressor, combustion chamber and turbine. The engine requires other components such as a compressor shroud, flange housing, housing, stator tube and exhaust nozzle. The manufacturing of components is used to produce a perfect micro turbojet engine duty cycle. After the manufacturing process is complete, measurements between the design blue print and the components of the manufacturing results have been carried out. There are dimensional differences in some components with the design blue print, due to the lack of available manufacturing tools. From this research, the Micro Turbojet Engine Aero- 16 has been successfully realized, and it is hoped that it will produce useful specifications and features to facilitate learning about the gas turbine engine working system on an airplane

Alternative fuel engine duty cycle

In developing promising systems for reducing the toxicity of ICE emissions, special attention is paid to suppressing the formation of toxic components directly in the engine’s working chamber. This primarily relates to nitrogen oxides. The method is of particular interest when using aqueous solutions of ethanol as fuel. Therefore, the study of the ignition and combustion capabilities of various fuels includes the study of the prospects for using water-saturated air-fuel mixtures in a multi-fuel operating cycle to reduce the emission of nitrogen oxides. It is assumed that the formation of shock and detonation waves as a result of self-ignition in local foci is acceptable if they propagate attenuate to a level that does not pose a danger to the engine design and does not impair its effective performance.

An Algebraic Model for Structural and Life Analysis of Regeneratively-Cooled Thrust Chambers

An algebraic model to evaluate the structural behavior and the cyclic life of regeneratively cooled thrust chambers is presented. The model is based on the evaluation of the stresses, displacements, and elastoplastic strains induced by the severe thermomechanical environment under which the regeneratively cooled thrust chambers operate. The evaluation of the strain range accumulated during an engine duty cycle is then used to estimate the cyclic life by considering the so-called doghouse effect: that is, the peculiar deformation of the chamber inner wall that accumulates cycle after cycle. The cyclic life model is taken and rearranged from an already existing model. Both low-cycle fatigue and tensile ductile ruptures are considered as possible failure mechanisms. A minimum number of inputs are required for the application of the model: the geometry of the investigated section; the hot-gas and coolant pressures; and the wall temperature in the inner and outer walls. Of course, material characterization (mainly in terms of the stress–strain behavior and low cycle fatigue) must also be provided. After the model description and setup, a wide database of experimentally tested thrust chambers (which is almost unique in the technical and scientific literature) is reproduced for the sake of model verification.

Developing the Automatic System for the Multi-Point Fumigation of Air Charge in the Diesel Engine

Introduction. The study deals with enhancement of an automotive diesel engine duty cycle through fumigating air charge by the certain dose (10−20 %) of hydrocarbon activator (alcohol, gasoline, kerosene, biodiesel, etc.). This is a relevant problem in engineering. In spite of its effectiveness, this method has not yet been widely applied to machinery. The existing mechanical devices for fumigating air charge do not provide the exact dosage of activator and its timely supply in a diesel engine at different operating modes. Materials and Methods. The solution for this problem may be the development of an automatic system for the multi-point fumigation of air charge. This device performs the injection of activator into the diesel engine intake manifold branches with the help of electromagnetic injectors managed by the electronic control unit. The system should provide the injectors operation by the algorithm for the cylinders firing order and calculate the injection duration for the adjusted activator dose. For the programming of the Electronic Control Unit, the injection duration of the exact activator dose was theoretically calculated. The algorithm of electromagnetic injectors operation was substantiated (for D-243 tractor diesel engine by the example). Results. To implement the multi-point fumigation of air charge, it was determined that depending on the activator dose and the engine speed and load mode, the cyclic dose of activator amounts may be from 1 mg per cycle to 13 mg per cycle, while the activator injection duration is from 0.27 ms to 3.5 ms. For the practical realization of the multi-point fumigation of air charge for D-243 diesel engine of MTZ-82.1 tractor the automatic system was designed. The system consists of an activator tank, filter, electric pump, rail, pressure regulator, electromagnetic injectors, electronic control unit, fuel consumption sensor, and sensor of phase and crankshaft speed. Conclusions. The device solves the problem of the automatic fumigation of air charge at the intake stroke and helps to improve power, fuel economy and environmental indicators of the automotive diesel engines. Keywords: diesel engine, fumigation of air charge, activator, system, electromagnetic injector, electronic control unit, sensor For citation: Ryblov M. V., Ukhanov D. A., Ukhanov A. P. Developing the Automatic System for the Multi-Point Fumigation of Air Charge in the Diesel Engine. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):523–536. DOI: https://doi.org/10.15507/0236-2910.028.201804.523-536 Acknowledgements: The authors thank the engineer of PNIEI company A. V. Grunyushkin for help in invention of Electronic Control Unit and in programming of microcontroller; the President of GAKS-Armservis Research and Manufacturing Association, D.Sc. (Engineering), professor S. V. Seynov for help in manufacturing of the modified intake manifold for diesel engine. Special thanks to anonymous reviewers for the objective analysis of the article.

Derivation of a Representative Engine Duty Cycle from On-Road Heavy-Duty Vehicle Driving Data

The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting these heavy-duty diesel engines to run on natural gas-diesel dual-fuel, a transient engine duty cycle representing the real-world engine working conditions is necessary. In this paper, a methodology is proposed, and a target engine duty cycle comprising of 2231 seconds is developed from on-road data collected from 11 on-road sand and water hauling trucks. The similarity of inherent characteristics of the developed cycle and the base trip observed is evidenced by the 2.05% error of standard deviation and average values for normalized engine speed and engine torque. Our results show that the proposed approach is expected to produce a representative cycle of in-use heavy-duty engine behavior.

Size-Resolved Emissions of Organic Tracers from Light- and Heavy-Duty Vehicles Measured in a California Roadway Tunnel

Individual organic compounds found in particulate emissions from vehicles have proven useful in source apportionment of ambient particulate matter. Species of interest include the hopanes, originating in lube oil, and selected PAHs generated via combustion. Most efforts to date have focused on emissions and apportionment PM10 or PM2.5 However, examining how these compounds are segregated by particle size in both emissions and ambient samples will help efforts to apportion size-resolved PM, especially ultrafine particles which have been shown to be more potent toxicologically. To this end, high volume size-resolved (coarse, accumulation, and ultrafine) PM samples were collected inside the Caldecott tunnel in Orinda, California to determine the relative emission factors for these compounds in different size ranges. Sampling occurred in two bores, one off-limits to heavy-duty diesel vehicles, which allows determination of the different emissions profiles for diesel and gasoline vehicles. Although tunnel measurements do not measure emissions over a full engine duty cycle, they do provide an average emissions profile over thousands of vehicles that can be considered characteristic of "freeway" emissions. Results include size-fractionated emission rates for hopanes, PAHs, elemental carbon, and other potential organic markers apportioned to diesel and gasoline vehicles. The results are compared to previously conducted PM2.5 emissions testing using dynamometer facilities and othertunnel environments.

Paper 4: Critical Factors in the Application of Diesel Engines to Rail Traction

The authors consider that the operation of diesel engines for rail traction is arduous because of the ‘on-off’ operation of the engine duty cycle in service, and hence thermal cycling is more severe than that in other applications. The joint paper discusses the limitations of the cooling systems, the turbo-blower and its lubrication, and the arrangements made to ensure that fuel input is related to turbo-blower speed during acceleration of the engine. The silencing of diesel engines is of additional importance from the exhaust noise aspect and from the mechanical noise of the engine itself. The rating of diesel engines is discussed briefly, as are overhaul life, ease of maintenance, and reliability.

Nuclear Rocket Engine Controls in an Orbital Transfer Role

It is assumed that the mission for a nuclear rocket upper-stage vehicle is the transfer from a 300-mile earth orbit to a corotational earth orbit. An engine of the solid fuel, heat exchanger type is assumed and briefly described. The engine duty cycle requirements are deduced from the incremental velocity requirements of the mission. Controls attention is fixed on the thrust programmer without discussion of the equally important sequence control aspects. A constant specific impulse, variable thrust controls approach is taken. Basic principles underlying this approach are discussed. Fineness of control and restart capability are pointed out as inherent features of the engine. These augment the well-known performance advantages due to the high specific impulse of nuclear rocket engines.