scholarly journals Effect of boosting system architecture and thermomechanical limits on diesel engine performance: Part-I—Steady-state operation

2017 ◽  
Vol 19 (8) ◽  
pp. 854-872
Author(s):  
José Galindo ◽  
Hector Climent ◽  
Olivier Varnier ◽  
Chaitanya Patil

Internal combustion engine developments are more focused on efficiency optimization and emission reduction for the upcoming future. To achieve these goals, technologies like downsizing and downspeeding are needed to be developed according to the requirement. These modifications on thermal engines are able to reduce fuel consumption and [Formula: see text] emission. However, implementation of these kind of technologies asks for right and efficient charging systems. This article consists of study of different boosting systems and architectures (single- and two-stage) with combination of different charging systems like superchargers and e-boosters. A parametric study is carried out with a zero-dimensional engine model to analyze and compare the effects of these different architectures on the same base engine. The impact of thermomechanical limits, turbo sizes and other engine development option characterizations are proposed to improve fuel consumption, maximum power and performance of the downsized/downspeeded diesel engines.

2017 ◽  
Vol 19 (8) ◽  
pp. 873-885 ◽  
Author(s):  
José Galindo ◽  
Hector Climent ◽  
Olivier Varnier ◽  
Chaitanya Patil

Nowadays, internal combustion engine developments are focused on efficiency optimization and emission reduction. Increasing focus on world harmonized ways to determine the performance and emissions on Worldwide harmonized Light vehicles Test Procedure cycles, it is essential to optimize the engines for transient operations. To achieve these objectives, the downsized or downspeeded engines are required, which can reduce fuel consumption and pollutant emissions. However, these technologies ask for efficient charging systems. This article consists of the study of different boosting architectures (single stage and two stage) with a combination of different charging systems like superchargers and e-boosters. A parametric study has been carried out with a zero-dimensional engine model to analyze and compare different architectures on the different engine displacements. The impact of thermomechanical limits, turbo sizes and other engine development option characterizations is proposed to improve fuel consumption, maximum power and performance of the downsized/downspeeded diesel engines during the transient operations.


Author(s):  
Tigran Parikyan ◽  
Thomas Resch

The paper discusses the importance of a numerical method for fast and accurate prediction of main bearing loads of inner combustion engine and its place in the concept phase of engine development process. An approach based on linear dynamic analysis of 3D engine model in frequency domain is presented. Implemented within a separate module of AVL software package EXCITE Designer, it delivers a combination of accuracy and performance suitable for this task. An application example illustrates the method.


Author(s):  
Apostolos Pesiridis ◽  
Benjamin Dubois ◽  
Ricardo F. Martinez-Botas

The present paper discusses the impact of a new type of turbocharger, namely, the Active Control Turbocharger (ACT). The aim of this work was to prove the advantage of this type of turbocharger over the current state-of-the-art: the Variable Geometry Turbocharger (VGT). This was achieved by carrying out a comparison between two commercial Diesel engine models (through the use of a commercial engine simulation software), which belong to the same family: one 10 litre engine equipped with VGT (originally) was consecutively compared to the same model of engine modified for ACT operation and through the integration of the ACT into the 81 version of the same engine in order to demonstrate the ACT’s downsizing capability. The study has been carried out for speeds between 800 and 2000 rpm, and a fuel-air ratio range of between 0.017 and 0.057. The results showed that the actuation of the turbine in ACT mode (through the sinusoidal regulation of the turbine inlet area with each incoming exhaust gas pressure pulse) increases greatly the energy available at the turbine inlet. This leads to an increase of the boost pressure at the intake of the engine by an average 30%. The specific fuel consumption was found to be similar throughout engine operating range with a penalty of up to 10% for the ACT engine of the same size (10 litre). A comparison was then carried out between the 10 litre VGT engine and the 8 litre ACT engine. The 8 litre has been found to produce up to 37% more torque and horse power under 1400 rpm and obtained very similar performance to the 10 litre VGT engine at higher speeds. At constant power output between the 8 and 10 litre engines, it has been found that the fuel consumption was decreased by a maximum of 9% when using the 8 litre engine. The results of the present study were encouraging with respect to the potential of ACT to downsize the internal combustion engine.


2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Hossein Balaghi Enalou ◽  
Serhiy Bozhko

Abstract With design trends toward the more electric engine (MEE) for the more electric aircraft (MEA), novel technologies can be pinpointed for multi-spool engines. Provided that a multi-spool MEE is equipped with electrical machines connected to each of its shafts, using power electronic converters (PECs) within a common high-voltage DC bus configuration, it is possible to redistribute a desired amount of power between the engine shafts independent of their speeds. This paper presents the impact of electric power transfer (EPT) on engine performance by using a developed 0-dimensional engine model based on the inter-component volume (ICV) method and engine component maps. Generic component maps are scaled to match the design point of the CFM56-3 engine. Validating the simulation results with engine performance data from literature shows that the steady-state error of the speed and fuel consumption is within 1% and 3.5% for the high- and low-speed settings, respectively, which is acceptable for the purpose of power transfer studies. It is shown that a 400 kW EPT system is the best performing for the cases run for the CFM56-3 engine, which can halve the amount of bleed air from variable bleed valves (VBVs). Results show that EPT with the rescheduled VBVs opening improves the engine performance significantly at low-speed settings by decreasing fuel consumption and increasing surge margins. Detailed simulation results from the engine model and EPT weight penalty analysis show that fuel consumption for short- and medium-haul flights reduces by up to 0.46% and 0.79% with state-of-the-art, and 0.60% and 1.0% with future technologies, respectively. Furthermore, results show that electric power transfer can recover the surge margins of degraded engines at high-speed settings.


Author(s):  
Jakub Lasocki

The World-wide harmonised Light-duty Test Cycle (WLTC) was developed internationally for the determination of pollutant emission and fuel consumption from combustion engines of light-duty vehicles. It replaced the New European Driving Cycle (NEDC) used in the European Union (EU) for type-approval testing purposes. This paper presents an extensive comparison of the WLTC and NEDC. The main specifications of both driving cycles are provided, and their advantages and limitations are analysed. The WLTC, compared to the NEDC, is more dynamic, covers a broader spectrum of engine working states and is more realistic in simulating typical real-world driving conditions. The expected impact of the WLTC on vehicle engine performance characteristics is discussed. It is further illustrated by a case study on two light-duty vehicles tested in the WLTC and NEDC. Findings from the investigation demonstrated that the driving cycle has a strong impact on the performance characteristics of the vehicle combustion engine. For the vehicles tested, the average engine speed, engine torque and fuel flow rate measured over the WLTC are higher than those measured over the NEDC. The opposite trend is observed in terms of fuel economy (expressed in l/100 km); the first vehicle achieved a 9% reduction, while the second – a 3% increase when switching from NEDC to WLTC. Several factors potentially contributing to this discrepancy have been pointed out. The implementation of the WLTC in the EU will force vehicle manufacturers to optimise engine control strategy according to the operating range of the new driving cycle.


Author(s):  
Alex Oliveira ◽  
Junfeng Yang ◽  
Jose Sodre

Abstract This work evaluated the effect of cooled exhaust gas recirculation (EGR) on fuel consumption and pollutant emissions from a diesel engine fueled with B8 (a blend of biodiesel and Diesel 8:92%% by volume), experimentally and numerically. Experiments were carried out on a Diesel power generator with varying loads from 5 kW to 35 kW and 10% of cold EGR ratio. Exhaust emissions (e.g. THC, NOX, CO etc.) were measured and evaluated. The results showed mild EGR and low biodiesel content have minor impact of engine specific fuel consumption, fuel conversion efficiency and in-cylinder pressure. Meanwhile, the combination of EGR and biodiesel reduced THC and NOX up to 52% and 59%, which shows promising effect on overcoming the PM-NOX trade-off from diesel engine. A 3D CFD engine model incorporated with detailed biodiesel combustion kinetics and NOx formation kinetics was validated against measured in-cylinder pressure, temperature and engine-out NO emission from diesel engine. This valid model was then employed to investigate the in-cylinder temperature and equivalence ratio distribution that predominate NOx formation. The results showed that the reduction of NOx emission by EGR and biodiesel is obtained by a little reduction of the local in-cylinder temperature and, mainly, by creating comparatively rich combusting mixture.


2014 ◽  
Vol 663 ◽  
pp. 336-341 ◽  
Author(s):  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff ◽  
Aminuddin Saat ◽  
Mazlan Said ◽  
Shaiful Fadzil Zainal Abidin

In this paper, engine simulation tool is used to investigate the effect of variable intake manifold and variable valve timing technologies on the engine performance at full load engine conditions. Here, an engine model of 1.6 litre four cylinders, four stroke spark ignition (SI) engine is constructed using GT-Power software to represent the real engine conditions. This constructed model is then correlated to the experimental data to make sure the accuracy of this model. The comparison results of volumetric efficiency (VE), intake manifold air pressure (MAP), exhaust manifold back pressure (BckPress) and brake specific fuel consumption (BSFC) show very well agreement with the differences of less than 4%. Then this correlated model is used to predict the engine performance at various intake runner lengths (IRL) and various intake valve open (IVO) timings. Design of experiment and optimisation tool are applied to obtain optimum parameters. Here, several configurations of IRL and IVO timing are proposed to give several options during the engine development work. A significant improvement is found at configuration of variable IVO timing and variable IRL compared to fixed IVO timing and fixed IRL.


Author(s):  
Derek Johnson ◽  
Marc Besch ◽  
Nathaniel Fowler ◽  
Robert Heltzel ◽  
April Covington

Emissions compliance is a driving factor for internal combustion engine research pertaining to both new and old technologies. New standards and compliance requirements for off-road spark ignited engines are currently under review and include greenhouse gases. To continue operation of legacy natural gas engines, research is required to increase or maintain engine efficiency, while reducing emissions of carbon monoxide, oxides of nitrogen, and volatile organic compounds such as formaldehyde. A variety of technologies can be found on legacy, large-bore natural gas engines that allow them to meet current emissions standards — these include exhaust after-treatment, advanced ignition technologies, and fuel delivery methods. The natural gas industry uses a variety of spark plugs and tuning methods to improve engine performance or decrease emissions of existing engines. The focus of this study was to examine the effects of various spark plug configurations along with spark timing to examine any potential benefits. Spark plugs with varied electrode diameter, number of ground electrodes, and heat ranges were evaluated against efficiency and exhaust emissions. Combustion analyses were also conducted to examine peak firing pressure, location of peak firing pressure, and indicated mean effective pressure. The test platform was an AJAX-E42 engine. The engine has a bore and stroke of 0.216 × 0.254 meters (m), respectively. The engine displacement was 9.29 liters (L) with a compression ratio of 6:1. The engine was modified to include electronic spark plug timing capabilities along with a mass flow controller to ensure accurate fuel delivery. Each spark plug configuration was examined at ignition timings of 17, 14, 11, 8, and 5 crank angle degrees before top dead center. The various configurations were examined to identify optimal conditions for each plug comparing trade-offs among brake specific fuel consumption, oxides of nitrogen, methane, formaldehyde, and combustion stability.


2015 ◽  
Vol 77 (8) ◽  
Author(s):  
S. F. Zainal Abidin ◽  
M. F. Muhamad Said ◽  
Z. Abdul Latiff ◽  
I. Zahari ◽  
M. Said

There are many technologies that being developed to increase the efficiency of internal combustion engines as well as reducing their fuel consumption.  In this paper, the main area of focus is on cylinder deactivation (CDA) technology. CDA is mostly being applied on multi cylinders engines. CDA has the advantage to improve fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6L four cylinders gasoline engine is studied. One-dimensional (1D) engine modeling work is performed to investigate the effect of intake valve strategy on engine performance with CDA. 1D engine model is constructed based on the 1.6L actual engine geometries. The model is simulated at various engine speeds at full load conditions. The simulated results show that the constructed model is well correlated to measured data. This correlated model is then used to investigate the CDA application at part load conditions. Also, the effects on the in-cylinder combustion as well as pumping losses are presented. The study shows that the effect of intake valve strategy is very significant on engine performance. Pumping losses is found to be reduced, thus improve fuel consumption and engine efficiency.


Author(s):  
Francesco Montella ◽  
J. P. van Buijtenen

This paper presents a simplified and fast method to evaluate the impact of a single engine component design on the overall performance. It consists of three steps. In the first step, an engine system model is developed using available data on existing engines. Alongside the cycle reference point, a sweep of operating points within the flight envelop is simulated. The engine model is tuned to match a wide range of conditions. In the second step, the module that contains the engine component of interest is analyzed. Different correlations between the component design and the module efficiency are investigated. In the third step, the deviations in efficiency related to different component configurations are implemented in the engine baseline model. Eventually, the effects on the performances are evaluated. The procedure is demonstrated for the case of a two-spool turbofan. The effects of tip leakage in the low pressure turbine on the overall engine performance are analyzed. In today’s collaborative engine development programs, the OEMs facilitate the design process by using advanced simulation software, in-house available technical correlations and experience. Suppliers of parts have a limited influence on the design of the components they are responsible for. This can be rectified by the proposed methodology and give subcontractors a deeper insight into the design process. It is based on commercially available PC engine simulation tools and provides a general understanding of the relations between component design and engine performance. These relations may also take into account of aspects like production technology and materials in component optimization.


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