Turbocharged Diesel Engine Research Articles

Teaching Nonlinear Model Predictive Control with MATLAB/Simulink and an Internal Combustion Engine Test Bench

Model Predictive Control (MPC) is used for more and more applications in an industrial context. The applications are characterized by increasing complexity while the available computation time is getting smaller and smaller. MPC is the most important advanced control technique with even increasing importance. Hence, this topic should be covered in control lectures during the academic studies in order to prepare students for their future work. For the successful implementation of MPC algorithms, knowledge from multiple disciplines is crucial and needs to be taught. Besides teaching knowledge in classical control theory, especially fundamentals in the fields of modeling, simulation and numerical optimization are required for understanding MPC. Programming skills are inevitable to apply the concept in real-world applications.This paper presents a concept for teaching MPC from the theory to the application to real-world systems. Details about the lectures covering the relevant topics are given. In the hands-on exercises, students implement their own linear as well as nonlinear MPC in MATLAB/Simulink. As example application in the exercises, the air path of a turbocharged diesel engine with high pressure exhaust gas recirculation is investigated. At the end of the semester, students can test their developed controllers on a real diesel engine test bench and compete against each other for the best control performance.

Integrated modernization of the gas-and-air system of a turbocharged diesel engine (21/21)

Improving the exploitative and environmental performance of piston engines (PICE) is an urgent task for many engineers and scientists. The article presents the results of the upgrade of a gas-and-air system of a diesel PICE, carried out through changing the turbocharging system’s configuration and modernizing the design of the admittance collector. The authors present a review of studies on the given subject and a description of the object of the research. The study was conducted on the basis of bench tests at a manufacturing plant and mathematical modeling using ACTUS program. The results of experimental studies on the main indicators of a basic and upgraded PICEs are presented. The gas exchange processes in the PICE under examination were studied in detail using mathematical modeling. For the given diesel PICE, improvement of the gas-and-air system leads to a growth in charging efficiency by 2.45-3.92%, a decrease in scavenging factor by 3.11-6.31% and a reduction of specific fuel consumption up to 3.33%. In the conclusion, new directions for increasing the efficiency of the given PICE are offered.

The Ability to Use 50% Biodiesel and Supercharging Syngas in Dual Fuel Mode for a Turbocharging Diesel-engine Generator

The Ability to Use 50% Biodiesel and Supercharging Syngas in Dual Fuel Mode for a Turbocharging Diesel-engine Generator

Effects of Using JP8-Diesel Fuel Mixtures in a Pump Injector Engine on Engine Performance

JP-8 fuel used in the aviation industry, especially in military fields, is used as a common military fuel between NATO countries. As the basic substance of JP-8 fuel, kerosene flares at high temperatures directly increase aircraft safety and freezing point is around -49 ° C, it is advantageous to use easily in fuel systems. In this study, the effects of jp-8 and diesel fuel mixtures on engine performance were investigated experimentally. A 3-cylinder, four-stroke, turbocharged diesel engine with pump injector fuel system was used for this purpose. 5% JP8 was added to diesel fuel. It was used as a fuel in the engine and the obtained values were analyzed according to the diesel fuel.

A finite element analysis-computational fluid dynamics coupled analysis on thermal-mechanical fatigue of cylinder head of a turbo-charged diesel engine

A finite element analysis-computational fluid dynamics coupled analysis on the thermo-mechanical fatigue of cylinder head of a turbo-charged diesel engine was performed, and the complete simulation process is illustrated in this paper. In-cylinder combustion analysis and water jacket coolant flow analysis were conducted to provide heat transfer boundary conditions to the temperature field calculation of the cylinder head. Comparing with the conventional finite element analysis of cylinder head by which the heat transfer boundary conditions of the combustion and coolant sides are estimated, the present method coupled the three-dimensional combustion computational fluid dynamics and coolant computational fluid dynamics with the finite element analysis. Both computational fluid dynamics and finite element analysis obtain more accurate boundary conditions on their interface from each other, and thus, the present method improves accuracy of thermo-mechanical fatigue prediction. Based on the measured material performance parameters such as stress–strain curve under different temperatures and E–N curve, creep, and oxidation data material performance, the cylinder head–gasket–cylinder block finite element transient stress–strain field was calculated using ABAQUS. The thermo-mechanical fatigue analysis of cylinder head submodel was performed by using FEMFAT software that is based on the Sehitoglu model to predict the thermo-mechanical fatigue life of cylinder head. By comparing the measured and predicted temperatures of cylinder head, the temperature results showed a good agreement, and the error is less than 10%.

The non-regulated emissions from a turbo-charged diesel engine under steady-state operation with hydro-processed renewable diesel (HRD)

An application of hydro-processed renewable diesel (HRD) intended to reduce non-regulated emissions, including formaldehyde, acetaldehyde, benzene, toluene, and xylene (BTX), is proposed in this study, in association with the emissions from a turbo-charged common-rail direct-injection diesel engine under steady-state operation. Three types of fuel, pure petro-diesel, 20% HRD blended fuel (H20), and 20% biodiesel blended fuel (B20) were tested under various engine loads and engine speeds. According to the emissions analysis, in which the samples were collected and analyzed through the solid phase micro-extraction (SPME) technique adapted with a derivation method, a 20% addition of HRD reduced the emissions of formaldehyde, acetaldehyde, benzene, toluene, and xylene, as compared to D100 and B20.

排気タービン式過給ディーゼル機関の性能試験に関する実験研究（第1報） ──大気条件係数及び燃料温度が機関性能に及ぼす影響──

排気タービン式過給ディーゼル機関の性能試験に関する実験研究（第1報） ──大気条件係数及び燃料温度が機関性能に及ぼす影響──

Load characteristics of a turbocharged diesel engine when working on natural gas

The article presents the load characteristics of the diesel D-245.7 when working on the gas-diesel process. The graphs of changes in the parameters of the combustion process, heat release characteristics, and effective indicators are given. It is important to study the issues of converting diesel engines to natural gas, as diesel engine is the most common in the national economy. The most suitable way of converting diesel engines to natural gas is to implement a gas-diesel workflow, since it does not require a significant engine rework. Diesel D-245.7 was chosen as an object of study. In the course of the study, among other things, the load characteristics of this diesel engine were removed when working on the gas-diesel process. When analyzing the experimental data obtained for a gas-diesel process as compared to a diesel one, some features can be noted. The gas-diesel process shows an increase in the temperature and pressure of gases in the cylinder. Heat dissipation is much faster. This indicates the volumetric nature of the ignition and combustion of natural gas. Engine power during the transition to the gas-diesel process is maintained at the same level, while the consumption of diesel fuel due to replacement by natural gas is reduced several times.

Experiment investigation on the performance and regulation rule of two-stage turbocharged diesel engine for various altitudes operation

To satisfy intake demand under high-altitude condition, two-stage turbocharging system is matched for diesel engine. However, it is necessary to regulate turbocharging system at low altitude due to decline of overall system efficiency. Moreover, regulation rule of turbocharging system, in terms of regulation ability and overall efficiency, which is critical to engine performance and unclear for various altitudes operation so that regulation strategy of turbocharging system depends on numerous calibration. In this paper, regulation rules at various altitudes are investigated by experiments. Test result indicates regulation ability increases as altitudes rises up and provides less excess air coefficient with constant regulation area. Whereas, overall efficiency presents disparate tends at different altitude. Output torque and fuel consumption continue to deteriorate as the bypass valve opens at high altitude condition, while can be improved below 2000 m with reasonable regulation area due to greater overall efficiency. The effect of altitude on regulation area boundary and scope are acquired. Finally, optimal regulation strategy at various altitudes is proposed. Experiment results manifest the maximal increment of overall system efficiency achieves 7.3% and leads to fuel consumption reduction of 13.9 g/kW h under 2200r/min and 0 m condition, compared to fixed turbocharging system.

Potential of n-butanol/diesel blends for CI engines under post injection strategy and different EGR rates conditions

Blending n-butanol and diesel fuels in combination with a post injection strategy could accomplish the target of ultra-low soot emissions. However, the introduction of n-butanol leads to increased NOX emissions. Exhaust gas recirculation (EGR) technology is considered a suitable means of inhibiting the formation of NOX. Little research has been conducted on post injection strategies in conjunction with the effects of n-butanol/diesel blends and different EGR rates on engine emissions and combustion performances. In this investigation, a turbocharged diesel engine is used to explore the effect of n-butanol and EGR rates on engine emissions and combustion performances. Further, to gain a better understanding of the effect of EGR rates on compression ignition engines with different fuels, the energy distribution of cycle fuel mass with different EGR rates and fuels is analyzed. The four test fuels were as follows: pure diesel (D100), diesel with 10% n-butanol addition (NB10), diesel with 20% n-butanol addition (NB20), and diesel with 30% n-butanol addition (NB30). The results show that the use of post injection has little impact on the ignition delay time and brake thermal efficiency (BTE), and reduces the emissions of CO, HC, NOX, and soot by 33.3%, 10%, 25%, and 50%, respectively. Under certain post injection strategies, the addition of n-butanol (10%, 20%, and 30%) produced significant reduction in CO and soot emissions. Within the range of 10% and 20% EGR, NB20 fuel can achieve a balance between combustion performance and emissions under certain post injection strategies. In addition, NB30 fuel has the lowest soot and CO emission energy proportion and highest exchange heat energy proportion.

Evaluation of Performance and Emissions of Ceramic Coated Turbocharged Direct Injection Diesel Engine operated with Diesel and Biodiesel Blends

It is evident that the main derivatives of biodiesel obtained from the transesterification of vegetable oils are identified as a best suitable alternate fuel for conventional diesel fuel. However higher viscosity and poor volatility of biodiesel causes engine problems for long-term use in diesel engines. Preheating of biodiesel is one of the technique reducing the problems associated with the higher viscosity of biodiesel in diesel engines. The positive effect of increased operating temperature of ceramic-coated engine concept is incorporated to avoid the preheating and maximize the effective heat release of biodiesel. The combination of increased operating temperature associated with LHR engine and oxygenated nature of biodiesel ensure nearly complete combustion. The experiment was conducted on a four cylinder four stroke direct injection turbocharged diesel engine and the combustion chamber was coated with partially stabilized zirconia (PSZ) of 0.35 mm thickness over 0.15 mm thickness of NiCrAl bond coat. The performance and emissions of conventional turbocharged engine and ceramic coated turbocharged engine were analyzed using diesel and biodiesel blends.

Detailed study of key boundary parameters influence on a turbocharged diesel engine based on thermodynamic analysis

In present study, the test platform and computational fluid dynamics simulation model of a turbocharged diesel engine are employed to explore energy balance, exergy balance, exergy terms variation, exergy destruction formation causes and spatial distribution in wider adjustment ranges of intake air temperature, coolant temperature and exhaust gas recirculation rate at different working conditions in detail. The results indicate that first, adjusting intake air temperature from 30 °C to 70 °C, exergy efficiency, exergy destruction and exhaust energy are negatively correlated with intake air temperature, while the change trends of exhaust exergy and heat transfer terms are opposite. Secondly, enhancing coolant temperature from 50 °C to 90 °C, heat transfer terms decreases significantly and effective work increases, while exhaust terms and exergy destruction remain basically unchanged. Third, exhaust gas recirculation rate increases from 5% to 30%, heat transfer exergy decreases, while effective work increases first and then decreases, in-cylinder exergy destruction decreases first and then increases. Fourth, there are several characteristics of in-cylinder exergy destruction at different key boundary parameters: (a) exergy destruction chiefly occurs in combustion process, (b) high exergy destruction rate primarily focuses in richer mixture region, (c) exergy destruction rate is negatively correlated with in-cylinder local temperature in the same heat release rate region. Finally, root reasons for the influences of key boundary parameters on exergy destruction are in-cylinder local equivalent ratio and temperature. Adjusting of intake air temperature, coolant temperature and exhaust gas recirculation rate reasonably to enhance temperature and promote diluted mixing of oil-air appropriately can effectively suppress exergy destruction and optimize efficiency.

Experimental and numerical investigation on a novel gas turbocharging system for diesel engine power recovery at high altitude

Based on the analysis of the plateau performance for a 6 cylinder 8.6 L turbocharged diesel engine, a novel gas turbocharging system (GTS) is proposed to recover the engine power at high altitudes. Besides, a rolling-reflux combustor is designed to meet the structural requirements of GTS as well as to reduce the flow loss. Both the structure of the rolling-reflux combustor and the cycle thermal calculation of the GTS were described in detail in present work. The performance changes and the fuel consumption rate with engine speed at different altitudes of the GTS are compared to the original engine. Results show that when the altitude changes from 3 km to 5 km, the torque and power of the diesel engine with GTS can be recovered to that at sea level. Then, the particle image velocimetry (PIV) test is performed to study the cold flow field at the cylinder head of the rolling-reflux combustor, and the flow conditions are analyzed in detail. Finally, the flow bench is built and the aerodynamic experiment is carried out to verify the effectiveness of GTS.

Coupled simulation of a thermoelectric generator applied in diesel engine exhaust waste heat recovery

This work develops a heat transfer model of a thermoelectric generator to explore the coupled relationship between high temperature exhaust flows, structure, and the external cooling air. The coupled heat transfer results showed that the fins reached a uniform high temperature, for the rated speed, the average temperature is 474 K. The coupled design scheme of the thermoelectric generator tested by installing it in a 4-cylinder turbocharged Diesel engine exhaust system. Comparison of the test and simulation results showed that as engine speed in-creased, the inlet and outlet exhaust temperatures of the thermoelectric generator exhibited a parabolic trend increase. The cooling water outlet temperature and the top, middle, and bottom fin temperatures increased linearly, and the coupled model was verified. From idle speed to rated speed, the top, middle, and bottom fin temperatures increased from 458 K to 476 K, 417 K to 463 K, and 406 K to 449 K, respectively; the cooling water outlet temperature increased from 293.6 K to approximately 303 K. Hence, the thermoelectric components installed in fins can experience temperature differences of over 100 K, the heat transfer efficiency can increase which ensures consistent output performance of the thermoelectric generator based on coupled design between the heat exchanger and thermoelectric modules array column.

Zero-dimensional modelling of a four-cylinder turbocharged diesel engine with variable compression ratio and its effects on emissions

With emission legislation becoming ever more stringent, declining fossil resources and an increase in greenhouse effect caused by CO2 emissions, manufacturers are exploring new ways to match the emissions regulations without compromising on the performance of the engine. This study included development of zero-dimensional model of a 2.0 L turbocharged diesel engine and then study the effects of changing its compression ratio in the numerical model. This paper gave a framework in determining the effect of compression ratios in different operational conditions of the engine. Implementation of variable compression ratio technology on a numerical model proved to be very cost-effective, time saving and validated the fact that numerical models can be used to study different parameters of the engines during the development stage. The main effect of an increase in compression ratio, was found to be as expected, a decrease in brake specific fuel consumption and an increase in thermal efficiency with a greater impact at low rpm-low load regions. Assuming, that the variable compression ratio technology can be utilized in the engine, this work found the best combination of compression ratios around the engine map, giving a best fit of trade-offs between the emissions and performance of the engine. This study also validates the fact that variable compression ratio technology, if implemented in the engine could not only reduce emissions of the engine but can be given as an option to the end-user to switch to more economic fuel consumption values during idling or cruising at long distant journeys.

Effects of dimethyl carbonate and 2-ethylhexyl nitrate on energy distribution, combustion and emissions in a diesel engine under different load conditions

Dimethyl carbonate (DMC)/diesel blended fuels are receiving increasing attention due to the advantages of DMC (oxygen content 53.3%) that improved the fuel-rich zone of diesel engines. However, the low cetane number (CN) of DMC/diesel dual-fuel at low loads resulted in a delayed combustion progress. Since the combustion phase had a significant effect on thermal efficiency, exergetic efficiency, energetic and exergetic losses; 2-ethylhexyl nitrate (EHN) was added to the mixed fuel as a CN improver, so that the combustion phase closed to that of diesel to ensure proper combustion characteristics of the DMC/diesel dual-fuel. In this study, a four-cylinder turbocharged diesel engine was used to study performance and emissions. Based on experiments, combustion characteristics including energy balance and exergy balance were focused, in which the EHN was added to the DMC/diesel mixture at different concentrations. The five test fuels included diesel (D100), and a mixture of 20% DMC with 80% diesel (DMC20). In addition, EHN was added to DMC20 at a ratio of 0.5%, 1%, and 2%. The results showed that EHN could shorten the ignition delay time of DMC and reduced maximum pressure rise rate (MPRR). The use of EHN improved brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), under the same load, using 0.5% and 2% EHN, BTE increased by 0.2% and 1%, relative to DMC20, respectively. The study found that the energy efficiency and exergy efficiency were higher after adding EHN, which made up for the burning problem of DMC. Moreover, the irreversible loss reduced, and the available work and available energy increased. Thermodynamic analysis showed that DMC had better combustion performance than diesel after adding 2% EHN. In this study, the method of EHN/DMC/diesel blended fuel combining with 25% EGR was proposed and confirmed that the trade-off relationships of NOX and soot have been improved noteworthy.

The performance of turbocharged diesel engine with injected calophyllum inophyllum methyl ester blends and inducted babul wood gaseous fuels

The current investigation briefly elaborates usage of calophyllum inophyllum biodiesel and babul-derived gas on a turbocharged diesel engine operated in dual fuel mode taking into consideration two different phases of operation. Initially, the experimentation was to be carried out keeping the gas flow rate fixed at 21.58 kg/h with varying loading condition in contrast to the naturally aspirated mode. Secondly, the gas flow rate was varied for all the fuels with fixed optimal loading conditions at 3.77 kW. Meanwhile, the modified operating parameters such as injection timing (230bTDC), injection pressure (240 bar), combustion chamber (TrCC), nozzle hole geometry (4-hole) were kept constant throughout the set of experimentations. The present work describes the novelty of varying the gas flow rate techniques with modified engine parameters in order to discuss the overall performance, and emission and combustion behavior in contrast to conventional diesel fuel. The result concludes a lower thermal efficiency (BTE) for B20 + P gas (21.58 kg/h) of 2.7%↓ while higher exhaust gas temperature (EGT) and brake specific energy consumption (BSEC) of 3.7%↑ and 2.18%↑ at 3.77 kW than diesel + P gas. Additionally, considering emission analysis, carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), nitric oxide (NO) and smoke opacity delivers a lower emission range for B20 + P gas of about 24.4%↓, 7.14%↓, 60.8%↓, 14.28%↓ and 42.8%↓ in comparison to diesel + P gas at optimal loading conditions. Moreover, varying the producer gas flow rate depicted a lower BTE and higher BSEC, EGT for B20 at maximum flow rate of 21.58 kg/h was 7.6%↓, 1.7%↑and 6.7%↑ in contrast to conventional fuel. Furthermore, CO, CO2, HC, NO and smoke opacity delivers a very low emission range of 15.2%↓, 8.42%↓, 20.5%↓, 29.6%↓ and 49.3%↓ in contrast to diesel fuel in dual fuel mode. Hence, considering the above discussion, engine with optimal load of 3.77 kW and gas flow rate of 21.58 kg/h along with modified engine parameters as discussed above enhanced the engine’s overall performance. This provides a freedom from using conventional resources resulting in both diesel fuel savings and energy security for future development.

Analysis of the Effects of Catalytic Converter on Automotive Engines Performance Through Real-Time Simulation Models

Today restrictions on pollutant emissions require the use of catalyst-based after-treatment systems as a standard both in SI and in Diesel engines. The application of monolith cores with a honeycomb structure is an established practice: however, to overcome drawbacks such as weak mass transfer from the bulk flow to the catalytic walls as well as poor flow homogenization, the use of ceramic foams has been recently investigated as an alternative showing better conversion efficiencies (even accepting higher flow through losses). The scope of this paper is to analyse the effects of foam substrates characteristics on engine performance. To this purpose a 0D “crank-angle” real-time mathematical model of an I.C.Engine developed by the Authors has been enhanced improving the heat exchange model of the exhaust manifold to take account of thermal transients and adding an original 0D model of the catalytic converter to describe mass flows and thermal processes. The model has been used to simulate a 1.6l turbocharged Diesel engine during a driving cycle (EUDC). Effects of honeycomb and foam substrates on fuel consumption and on variations of catalyst temperatures and pressures are compared in the paper.

Inverted Brayton Cycle for waste heat recovery in reciprocating internal combustion engines

Energy recovery in reciprocating internal combustion engines is one of the most investigated topics for reducing fuel consumption and carbon dioxide emissions in the on-the-road transportation sector. An exhaust gas recovery opportunity is represented by a power unit with a so-called inverted Brayton cycle (IBC). The gas is used as the working fluid, which expands inside a turbine when it falls below atmospheric pressure; after being cooled by an external source, it is re-compressed to the atmospheric value. The useful work is the difference between the one produced by the turbine and that absorbed by the compressor. In this study, a thermodynamic assessment of the opportunity to apply an IBC-based power unit to a turbocharged diesel engine was conducted, and the most important parameters affecting the range of possible recovery (turbine and compressor efficiencies, pressure drops) were evaluated, and the pressure ratio was optimized. A conventional bottomed layout shows a recovery of approximately 1.5% of the engine’s mechanical power when a homologation heavy duty procedure is performed. An improved integration, in which the IBC turbine is placed upstream of the turbocharger one, makes it possible to partially recover the energy losses related to the turbocharger control device, which leads to an average recoverable power of approximately 2% of the engine brake power. Concerns about possible water condensation in the exhaust have also been thoroughly investigated, and they can be managed in temperate weather.

Prediction of turbocharged diesel engine performance equipped with an electric supercharger using 1D simulation

The electric supercharger has the advantages of reducing turbo lag and improving low-speed torque of turbocharged engine. The steady-state model using 1D simulation was performed to analyze the effect of the supercharger on the increase of BMEP and the combustion phenomena. Also, transient simulation using a mean value engine model (MVEM) was performed to analyze the improvement of engine response and fuel economy. The differences of engine performance were analyzed according to three locations (Layout A, B, and C) of the supercharger and the air-fuel ratio under controlled and uncontrolled conditions. The BMEPs increased 140.3%, 65.6%, and 17.3%, based on the maximum BMEP of the engine under the air-fuel ratio controlled condition in 1000 rpm, 1250 rpm, and 1500 rpm respectively. The validity of the BMEP analysis can be verified through the results of the combustion pressure; the results seem reasonable in this respect. The volumetric efficiency, maximum combustion temperature, and intake mass flow rate were compared to analyze the cause of volumetric efficiency change by using the supercharger and air-fuel ratio control. In addition, the total fuel consumption decreased by 18 g from 574 g to 556 g owing to the effect of the supercharger in the NEDC simulation.