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Technical Paper

13 Simulation of Dynamic Operation of a Single-Cylinder Two-Stroke Engine

2002-10-29
2002-32-1782
A drivetrain model incorporating detailed crankshaft and drivetrain dynamics has been incorporated into an unsteady gas dynamic computer simulation of a single-cylinder two-stroke engine. This study examines the change in predicted engine performance caused by relaxing the conventional assumption of constant crankshaft velocity, and a comparison of results is presented. Relaxing the assumption changed the predicted brake mean effective pressures by over 10%. Experimental validation of the simulation involved mounting an engine to a test bed and driving an inertia wheel through a fully characterized drivetrain. A high-speed data acquisition system measured signals from a position encoder mounted on the crankshaft and from a non-contact torque transducer. The time and position data were used to calculate instantaneous crankshaft speed, and these results were compared to the predicted profiles. Simulation results and experimental measurements are presented and discussed.
Technical Paper

15 Combustion Characteristics of an Improved Design of a Stratified Charge Spark Ignition Engine

2002-10-29
2002-32-1784
The characteristics of the combustion process in an improved design of a novel spark ignition engine studied by means of Computational Fluid Dynamics are presented. The engine is designed to work at low average combustion temperatures to achieve very low NOx emissions. The engine is a two-stroke, two piston in-line engine. The main combustion occurs in four combustion pre-chambers that have an annular shape with a nozzle on the side facing the cylinder. Fuel is directly injected into the pre-chambers by using high-pressure fuel injectors. A progressive burning process is expected to keep the flame inside the pre-chambers while the fast ejection of combustion products should produce effective mixing with the cold air in the cylinder. This fast dilution should guarantee a temperature drop of the combustion products thus reducing the formation of NOx via a thermal path.
Technical Paper

15 Years of Transfer Path Analysis VINS in the Vehicle NVH Development - Selected Results

2014-06-30
2014-01-2047
Transfer path analysis is a powerful tool to support the vehicle NVH development. On the one hand it is a fast method to gain an overview of the complex interplay in the vehicle noise generation process. On the other hand it can be used to identify critical noise paths and vehicle components responsible for specific noise phenomena. FEV has developed several tools, which are adapted to the considered noise phenomena: Powertrain induced interior noise and vibration is analyzed by VINS (Vehicle Interior Noise Simulation), which allows the deduction of improvement measures fast enough for application in the accelerated vehicle development process. Further on vehicle/powertrain combinations not realized in hardware can be evaluated by virtual installation of the powertrain in the vehicle, which is especially interesting in the context of engine downsizing from four to three or six to four cylinders.
Technical Paper

1500 W Deployable Radiator with Loop Heat Pipe

2001-07-09
2001-01-2194
Two-phase capillary loops are being extensively studied as heat collection and rejection systems for space applications as they appear to satisfy several requirements like low weight, low volume, temperature control under variable heat loads and/or heat sink, operation under on ground and micro gravity conditions, simplicity of mounting and heat transfer through tortuous paths. In 1998–2000 Alenia defined and Lavochkin Association developed the Deployable Radiator on the base of honeycomb panels, axial grooved heat pipes and Loop Heat Pipe. It was designed for on-ground testing.
Technical Paper

16 Optimisation of a Stratified Charge Strategy for a Direct Injected Two-Stroke Engine

2002-10-29
2002-32-1785
Direct fuel injection is becoming mandatory in two-stroke S.I. engines, since it prevents one of the major problems of these engines, that is fuel loss from the exhaust port. Another important problem is combustion irregularity at light loads, due to excessive presence of residual gas in the charge, and can be solved by charge stratification. High-pressure liquid fuel injection is able to control the mixing process inside the cylinder for getting either stratified charge at partial loads or quasi-stoichiometric conditions, as it is required at full load. This paper shows the development of this solution for a small engine for moped and light scooter, using numeric and experimental tools. In order to obtain the best charge characteristics at every load and engine speed, different combustion chambers have been conceived and studied, examining the effects of combustion chamber geometry, together with injector position and injection timing
Technical Paper

17 Study on Auto-Ignition and Combustion Completion of n-Butane in a Two-stroke Homogeneous Charge Compression Ignition (HCCI) Engine

2002-10-29
2002-32-1786
Homogeneous Charge Compression Ignition (HCCI) is good method to be higher efficiency and to reduce NOx emission and particular matter together than conventional SI combustion engine. But HCCI depends on chemical reaction of fuel and air mixture. So controlling of ignition timing is difficult, and HCCI is high THC and CO emissions because temperature can't reach the enough temperature to reduce those. In this study, we investigated factor for auto ignition timing and combustion completion on n-Butane/Air mixture by a two-stroke HCCI engine. Auto Ignition temperature are known to be decided by fuel(1), for n-Butane, the temperature was 1150±30K. And as we researched combustion completion from In-cylinder gas temperature, increasing In-cylinder gas temperature caused high combustion efficiency and low THC, CO emissions.
Technical Paper

18 Gasoline CAI and Diesel HCCI: the Way towards Zero Emission with Major Engine and Fuel Technology Challenges

2002-10-29
2002-32-1787
Engines and fuels for transport as well as off-road applications are facing a double challenge: bring local pollution to the level requested by the most stringent city air quality standard reduce CO2 emission in order to minimize the global warming risk. These goals stimulate new developments both of conventional and alternative engines and fuels technologies. New combustion processes known as Controlled Auto-Ignition (CAI™) for gasoline engine and Homogeneous Charge Compression Ignition (HCCI) for Diesel engine are the subject of extensive research world wide and particularly at IFP for various applications such as passenger cars, heavy-duty trucks and buses as well as small engines. Because of the thermo-chemistry of the charge, the thermal NOx formation and the soot production are in principle much lower than in flames typical of conventional engines.
Technical Paper

180MPa Piezo Common Rail System

2006-04-03
2006-01-0274
The challenge for the diesel engines today is to reduce harmful emissions, such as particulate matter (PM) and Nitrogen oxides (NOx), and enhance the fuel efficiency and power, which are its main advantages. To meet this challenge, DENSO has developed an advanced common rail system (CRS) that uses piezo actuated fuel injectors capable of delivering up to five injection events per combustion cycle at 180MPa, currently the world's highest commercially available diesel fuel injection pressure. The DENSO piezo injector incorporates an internally developed piezoelectric element that energizes quicker than its solenoid counterpart, thereby reducing the transition time for the start and end of the fuel injection event. The piezoelectric element and unique passage structure of the DENSO injector combine to provide a highly reliable and responsive fuel injection event.
Technical Paper

1941 CFR ROAD DETONATION TESTS - Further Experience with New Methods (Compiled from Report of the Cooperative Fuel Research Committee)

1942-01-01
420122
The cooperative road tests carried out during 1941 have added considerable information and experience to that already existing on the subject of road detonation testing. Extensive data were obtained on the fuel requirements of the 1940 and 1941 models of the three most popular cars. Corresponding data were obtained on the knocking characteristics of current gasolines representing the bulk of the sales volume in various parts of the United States. On account of large variations in octane-number requirement among different cars of the same make - due to differences in ignition timing, combustion-chamber deposit, and other causes - and on account of variations in commercial gasolines, it has been necessary to use statistical methods of analysis in the appraisal of fuel and engine relationships. These methods of analysis have been applied in a number of ways, and have proved very useful.
Technical Paper

1985 Light-Duty Truck Fuel Economy

1980-10-01
801387
This paper addresses fuel economy standards that can be obtained in 1985 for two-wheel drive LDT's using existing technology. To estimate the fuel economy, the fleet of LDT's is first segmented into market classes based on the concept of utility. The 1985 sales share of each class is predicted from an extrapolation of current trends as well as published sales forecasts. The 1985 fuel economy of each market class is projected using 1) MY '80 truck technology and fuel economy as a baseline, 2) a regression equation that allows an estimate of fuel economy based on the weight, drag, and engine displacement, and 3) the addition of fuel-efficient technologies. Estimates of weight reduction and new model introduction within each market class were derived from published manufacturers' plans. Based on this methodology, this analysis concludes that a fleet fuel economy in excess of 24/25 mpg is feasible for 1985 without/with the use of diesel engines.
Technical Paper

1D Engine Simulation Approach for Optimizing Engine and Exhaust Aftertreatment Thermal Management for Passenger Car Diesel Engines by Means of Variable Valve Train (VVT) Applications

2018-04-03
2018-01-0163
Using a holistic 1D engine simulation approach for the modelling of full-transient engine operation, allows analyzing future engine concepts, including its exhaust gas aftertreatment technology, early in the development process. Thus, this approach enables the investigation of both important fields - the thermodynamic engine process and the aftertreatment system, together with their interaction in a single simulation environment. Regarding the aftertreatment system, the kinetic reaction behavior of state-of-the-art and advanced components, such as Diesel Oxidation Catalysts (DOC) or Selective Catalytic Reduction Soot Filters (SCRF), is being modelled. Furthermore, the authors present the use of the 1D engine and exhaust gas aftertreatment model on use cases of variable valve train (VVT) applications on passenger car (PC) diesel engines.
Technical Paper

1D Fluid Dynamic Modeling of Unsteady Reacting Flows in the Exhaust System with Catalytic Converter for S.I. Engines

2000-03-06
2000-01-0210
This paper deals with some recent advances in the field of 1D fluid dynamic modeling of unsteady reacting flows in complex s.i. engine pipe-systems, involving a catalytic converter. In particular, a numerical simulation code has been developed to allow the simulation of chemical reactions occurring in the catalyst, in order to predict the chemical specie concentration in the exhaust gas from the cylinder to the tailpipe outlet, passing through the catalytic converter. The composition of the exhaust gas, discharged by the cylinder and then flowing towards the converter, is calculated by means of a thermodynamic two-zone combustion model, including emission sub-models. The catalytic converter can be simulated by means of a 1D fluid dynamic and chemical approach, considering the laminar flow in each tiny channel of the substrate.
Technical Paper

1D Model of a Copper Exchanged Small Pore Zeolite Catalyst Based on Transient SCR Protocol

2013-04-08
2013-01-1578
Urea-selective catalytic reduction (SCR) catalysts are the leading aftertreatment technology for diesel engines, but there are major challenges associated with meeting future NOx emission standards, especially under transient drive cycle conditions that include large swings in exhaust temperatures. Here we present a simplified, transient, one-dimensional integral model of NOx reduction by NH₃ on a commercial small-pore Cu-zeolite urea-SCR catalyst for which detailed kinetic parameters have not been published. The model was developed and validated using data acquired from bench reactor experiments on a monolith core, following a transient SCR reactor protocol. The protocol incorporates NH₃ storage, NH₃ oxidation, NO oxidation and three global SCR reactions under isothermal conditions, at three space velocities and at three NH₃/NOx ratios.
Technical Paper

1D Modeling Approach for Prediction of Heat Transfer in Exhaust Aftertreatment System and Sensors Module

2024-04-09
2024-01-2739
The study of temperature distribution and heat transfer over non-uniform geometry is of great importance to engineers because of universal occurrence in many engineering applications such as diesel engine, boilers, heaters, radiators, dosers, etc. Performance of engine and its components (mechanical and electronic) is highly depending upon efficient thermal management. An accurate heat transfer analysis is necessary in automotive application and power plant. This study presents one dimensional model for prediction of conjugate heat transfer in Aftertreatment system and Sensors Module (Nox Sensor, PM Sensor, EGTS etc..) for diesel engine. Three-dimensional conductive, convective and radiative thermal analysis is computationally expensive as underhood models are of complex shape in nature and total turnaround time for product development project is also significantly high.
Technical Paper

1D Modeling of Alternative Fuels Spray in a Compression Ignition Engine Using Injection Rate Shaping Strategy

2019-09-09
2019-24-0132
The Injection Rate Shaping consists in a novel injection strategy to control air-fuel mixing quality via a suitable variation of injection timing that affects the injection rate profile. This strategy has already provided to be useful to increase combustion efficiency and reduce pollutant emissions in the modern compression ignition engines fed with fossil Diesel fuel. But nowadays, the ever more rigorous emission targets are enhancing a search for alternative fuels and/or new blends to replace conventional ones, leading, in turn, a change in the air-fuel mixture formation. In this work, a 1D model of spray injection aims to investigate the combined effects of both Injection Rate Shaping and alternative fuels on the air-fuel mixture formation in a compression ignition engine. In a first step, a ready-made model for conventional injection strategies has been set up for the Injection Rate Shaping.
Technical Paper

1D Modeling of Expansion tank Flow

2015-01-14
2015-26-0194
An expansion tank is an integral part of an automotive engine cooling system. The primary function of the expansion tank is to allow the thermal expansion of the coolant. The expansion tank will be referred as hot bottle in this paper. In the System level modeling of the engine internal flow, it is imperative to accurately model and characterize the components in the system. It is often challenging to define the hot bottle accurately with limited parameters in the 1D modeling. Currently it is very difficult to optimize the system by testing. Since testing consumes a lot of time and changes in development stage. If the hot bottle component is not defined properly in the system network, then the system flow balancing cannot be predicted accurately. In this paper, the approach of creating a 1D modeling tool for hot bottle flow prediction is discussed and the simulation results are compared with the physical test data.
Technical Paper

1D Modeling of HVAC Unit Air Flow for Automatic Climate Control Simulations

2021-04-06
2021-01-0215
Advanced control techniques are widely used in different automotive applications including climate control. Significant costs associated with the development and calibration of such controllers can be reduced if these tasks are conducted in a virtual environment. Such a virtual environment can be developed by integrating the controller with the system model. Different scenarios can be then simulated to make sure functional objectives of the system are met. 1D models provide the necessary level of accuracy without imposing extra computational cost in such virtual environments. As such, they are perfect candidates for model, hardware or software-in-the loop validation benches for controls. Performance of a heating, ventilation and air-conditioning (HVAC) system can be controlled through the settings of the components like mode door, blend door, recirculation door, blower, and the compressor.
Technical Paper

1D Modeling of the Hydrodynamics and of the Regeneration Mechanism in Continuous Regenerating Traps

2006-09-14
2006-01-3011
The present work focuses on the simulation of the hydrodynamics, transient filtration/loading and catalytic/NO2-assisted regeneration of Diesel after-treatment systems. A 1D unsteady model for compressible and reacting flows for the numerical simulation of the behavior of Diesel Oxidation Catalysts (DOCs) and Diesel Particulate Filters (DPFs) has been developed. The numerical model is able to keep track of the amount of soot in the flow; the increasing of back-pressure through the exhaust system (mainly due to the Diesel Particulate Filter) can be predicted by the calculation of the permeability variation of the porous wall, as the soot particles goes inside the DPF. A sub-model for the regeneration of the collected soot has been developed: the collected particulate is oxidized by the Oxygen (O2) and by the Nitrogen Dioxide (NO2).
Technical Paper

1D Modelling of Reactive Fluid Dynamics, Cold Start Behavior of Exhaust Systems

2006-04-03
2006-01-1544
The introduction of more stringent standards for engine emissions requires a steady development of exhaust gas aftertreatment in addition to an optimized cylinder combustion. The reduction of the cold start phase can help significantly to lower cycle emissions. With the goal of optimizing the overall emission performance this study presents a comprehensive simulation approach. A well established 1D gas dynamics and engine simulation model is extended by three key features. These are models for combustion and pollutant production in the cylinder, models for the pollutant conversion in a catalyst, and a general species transport model. This allows to consider an arbitrary number of chemical species and reactions in the entire system.
Journal Article

1D Numerical and Experimental Investigations of an Ultralean Pre-Chamber Engine

2019-11-19
Abstract In recent years, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations. With this solution, in fact, it is possible to simultaneously reduce NOx raw emissions and fuel consumption due to decreased heat losses, higher thermodynamic efficiency, and enhanced knock resistance. However, the real applicability of this technique is strongly limited by the increase in cyclic variation and the occurrence of misfire, which are typical for the combustion of homogeneous lean air/fuel mixtures. The employment of a Pre-Chamber (PC), in which the combustion begins before proceeding in the main combustion chamber, has already shown the capability of significantly extending the lean-burn limit. In this work, the potential of an ultralean PC SI engine for a decisive improvement of the thermal efficiency is presented by means of numerical and experimental analyses.
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