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Prof. Dr. Muammer Özkan
Yıldız Technical University, Faculty of Mechanical Engineering, Division of Automotive

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0 Fuel
0 exergy
0 engine emission
0 Fuel Consumption
0 internal combustion engine

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Fuel Consumption
exergy
internal combustion engine
engine emission

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Journal article
Published: 22 December 2020 in Energies
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This work presents a numerical study that investigates the optimum post-injection strategy and internal exhaust gas recirculation (iEGR) application with intake valve re-opening (2IVO) aiming to optimize the brake specific nitric oxide (bsNO) and brake specific soot (bsSoot) trade-off with reasonable brake specific fuel consumption (BSFC) via 1D engine cycle simulation. For model validation, single and post-injection test results obtained from a heavy-duty single cylinder diesel research engine were used. Then, the model was modified for 2IVO application. Following the simulations performed based on Latin hypercube DoE; BSFC, bsNO and bsSoot response surfaces trained by feedforward neural network were generated as a function of the injection (start of main injection, post-injection quantity, post-injection dwell time) and iEGR (2IVO dwell) parameters. After examining the effect of each parameter on pollutant emission and engine performance, multi-objective pareto optimization was performed to obtain pareto optimum solutions in the BSFC-bsNO-bsSoot space for 8.47 bar brake mean effective pressure (BMEP) load and 1500 rpm speed condition. The results show that iEGR and post-injection can significantly reduce NO and soot emissions, respectively. The soot oxidation capability of post-injection comes out only if it is not too close to the main injection and its efficiency and effective timing are substantially affected by iEGR rate and main injection timing. It could also be inferred that by the combination of iEGR and post-injection, NO and soot could be reduced simultaneously with a reasonable increase in BSFC if start of main injection is phased properly.

ACS Style

Volkan AKGÜL; Orkun Özener; Cihan Büyük; Muammer Özkan. Numerical Investigation and Multi-Objective Optimization of Internal EGR and Post-Injection Strategies on the Combustion, Emission and Performance of a Single Cylinder, Heavy-Duty Diesel Engine. Energies 2020, 14, 15 .

AMA Style

Volkan AKGÜL, Orkun Özener, Cihan Büyük, Muammer Özkan. Numerical Investigation and Multi-Objective Optimization of Internal EGR and Post-Injection Strategies on the Combustion, Emission and Performance of a Single Cylinder, Heavy-Duty Diesel Engine. Energies. 2020; 14 (1):15.

Chicago/Turabian Style

Volkan AKGÜL; Orkun Özener; Cihan Büyük; Muammer Özkan. 2020. "Numerical Investigation and Multi-Objective Optimization of Internal EGR and Post-Injection Strategies on the Combustion, Emission and Performance of a Single Cylinder, Heavy-Duty Diesel Engine." Energies 14, no. 1: 15.

Journal article
Published: 10 January 2020 in Fuel
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The real driving emissions of vehicles have attracted great interest in recent years due to the increased environmental awareness. Public transport systems using internal combustion engines contributes greenhouse gases and harmful pollutants significantly. The routes of public transport mainly include urban areas with high population density. From this perspective, analyzing of the public transport systems real driving emissions is important for creating environmentally friendly cities. The economy of fossil fueled public transportation is another major concern that should be optimized. There are few studies focusing on the emission characteristics of public transport buses currently working on dedicated routes. In this context one of the biggest transport axle of the world, Metrobus Rapid Bus Transport system is analyzed. The Metrobus equipped with portable emission measurement systems and portable fuel consumption meter is used for measurement activities. Then the results are analyzed in terms of emissions and fuel consumption regarding to the operating parameters. The results showed that the driving behavior has great effect on both emissions and fuel consumption. It was shown that the accumulated emissions near bus stop can strongly affect the public health. The emissions and fuel consumption are both analyzed regarding to the acceleration and speed. The emissions and fuel factors are developed and compared with the values indicated in the literature. It was also analyzed that it is possible to lower emissions with operating the vehicle some certain regions.

ACS Style

Orkun Özener; Muammer Özkan. Fuel consumption and emission evaluation of a rapid bus transport system at different operating conditions. Fuel 2020, 265, 117016 .

AMA Style

Orkun Özener, Muammer Özkan. Fuel consumption and emission evaluation of a rapid bus transport system at different operating conditions. Fuel. 2020; 265 ():117016.

Chicago/Turabian Style

Orkun Özener; Muammer Özkan. 2020. "Fuel consumption and emission evaluation of a rapid bus transport system at different operating conditions." Fuel 265, no. : 117016.

Journal article
Published: 01 January 2018 in Thermal Science
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Public transportation fuel consumption modeling shows a great importance because of economic and environmental aspects. Considering to the metropolises with millions of inhabitants with circulating thousands of buses that uses intercity lines, its importance is becoming vital in planning both operation of transportation company and city mobility planning. In this context a detailed fuel consumption modelling approach for public transportation buses was used for vehicle fuel consumption assessment during operation. The methodology was developed with IPG TruckMaker + AVL Cruise co-simulation environment following instantaneous speed, load and 3D road data primarily besides model parameters. The model was validated at one of the most important public transportation axle of the world, Istanbul Metrobus System, at two direction which carries over ~1 Million passenger daily in 24 hours operation with petrol engine buses. The comparison simulation/measurements showed that the proposed fuel consumption model is accurate and can predict fuel consumption behavior for public transit buses in a reliable band. In addition, this methodology can be used to investigate various power train and operating scenarios near future for more efficient public transportation with high reliability.

ACS Style

Orkun Ozener; Muammer Ozkan; Emre Orak; Gunes Acarbulut. A fuel consumption model for public transportation with 3-D road geometry approach. Thermal Science 2018, 22, 1505 -1514.

AMA Style

Orkun Ozener, Muammer Ozkan, Emre Orak, Gunes Acarbulut. A fuel consumption model for public transportation with 3-D road geometry approach. Thermal Science. 2018; 22 (3):1505-1514.

Chicago/Turabian Style

Orkun Ozener; Muammer Ozkan; Emre Orak; Gunes Acarbulut. 2018. "A fuel consumption model for public transportation with 3-D road geometry approach." Thermal Science 22, no. 3: 1505-1514.

Journal article
Published: 01 January 2017 in Thermal Science
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In the modern Diesel injection systems the phasing of injection in the same cycle gives a high flexibility to engineers from the perspective of engines performance and emission optimization. Basically, the injection is separated in to three phases: the pilot, main, and post injection phases. The focus of this study is based on pilot injection strategy implementation, which can be used for emission control effectively. In this work, reference main and pilot + main injection strategy experiments were realized in a modern Diesel engine. The logged data groups were used to model the engine at 1-D thermodynamic simulation AVL BOOST. In the second stage of this work, the engine operating points which are not realized at test bench are made run at BOOST programme. The new model parameters of simulation are identified with artificial neural network technique. The results showed that the implementation of appropriate mass of pilot injection at the appropriate injection advance will reduce the NOx emissions compared to reference main injection strategy. For reducing CO emissions the pilot injection mass should also be kept in the same range with higher injection pressure that can be achieved. Usage of 1-D simulation programme coupled with artificial neural network was found useful up to a certain extent especially for parametric analyses and optimization problems via with validation of calibration parameters at a huge experimental data.

ACS Style

Orkun Ozener; Muammer Özkan; Levent Yuksek. Modelling analysis of multiple diesel injection strategies with one-dimensional simulation coupled with artificial neural networks. Thermal Science 2017, 21, 413 -425.

AMA Style

Orkun Ozener, Muammer Özkan, Levent Yuksek. Modelling analysis of multiple diesel injection strategies with one-dimensional simulation coupled with artificial neural networks. Thermal Science. 2017; 21 (1 Part B):413-425.

Chicago/Turabian Style

Orkun Ozener; Muammer Özkan; Levent Yuksek. 2017. "Modelling analysis of multiple diesel injection strategies with one-dimensional simulation coupled with artificial neural networks." Thermal Science 21, no. 1 Part B: 413-425.

Journal article
Published: 12 January 2015 in Entropy
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In this study, a four stroke four cylinder direct injection CI engine was run using three different injection pressures. In all measurements, the fuel quantity per cycle, the pre injection and main injection timing, the boost pressure and the engine speed were kept constant. The motor tests were performed under 130, 140 and 150 MPa rail pressure. During the theoretical part of the study, combustion, emission, energy and exergy analysis were made using the test results. An increase in the injection pressure increases combustion efficiency. The results show that combustion efficiency is not enough by itself, because the increase in the power need of the injection pump, decreases the thermal efficiency. The increase in the combustion temperature, increases the cooling loss and decreases the exergetic efficiency. In addition, the NOx emissions increased by 12% and soot emissions decreased 44% via increasing injection pressure by 17%. The thermal and exergetic efficiencies are found inversely proportional with injection pressure. Exergy destruction is found independent of the injection pressure and its value is obtained as ~6%.

ACS Style

Muammer Özkan. A Comparative Study on Energy and Exergy Analyses of a CI Engine Performed with Different Multiple Injection Strategies at Part Load: Effect of Injection Pressure. Entropy 2015, 17, 244 -263.

AMA Style

Muammer Özkan. A Comparative Study on Energy and Exergy Analyses of a CI Engine Performed with Different Multiple Injection Strategies at Part Load: Effect of Injection Pressure. Entropy. 2015; 17 (1):244-263.

Chicago/Turabian Style

Muammer Özkan. 2015. "A Comparative Study on Energy and Exergy Analyses of a CI Engine Performed with Different Multiple Injection Strategies at Part Load: Effect of Injection Pressure." Entropy 17, no. 1: 244-263.

Journal article
Published: 01 January 2014 in Fuel
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ACS Style

Orkun Özener; Levent Yüksek; Alp Tekin Ergenç; Muammer Özkan. Effects of soybean biodiesel on a DI diesel engine performance, emission and combustion characteristics. Fuel 2014, 115, 875 -883.

AMA Style

Orkun Özener, Levent Yüksek, Alp Tekin Ergenç, Muammer Özkan. Effects of soybean biodiesel on a DI diesel engine performance, emission and combustion characteristics. Fuel. 2014; 115 ():875-883.

Chicago/Turabian Style

Orkun Özener; Levent Yüksek; Alp Tekin Ergenç; Muammer Özkan. 2014. "Effects of soybean biodiesel on a DI diesel engine performance, emission and combustion characteristics." Fuel 115, no. : 875-883.

Journal article
Published: 01 April 2013 in Applied Thermal Engineering
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ACS Style

Muammer Özkan; Derya Burcu Özkan; Orkun Özener; Hasan Yılmaz. Experimental study on energy and exergy analyses of a diesel engine performed with multiple injection strategies: Effect of pre-injection timing. Applied Thermal Engineering 2013, 53, 21 -30.

AMA Style

Muammer Özkan, Derya Burcu Özkan, Orkun Özener, Hasan Yılmaz. Experimental study on energy and exergy analyses of a diesel engine performed with multiple injection strategies: Effect of pre-injection timing. Applied Thermal Engineering. 2013; 53 (1):21-30.

Chicago/Turabian Style

Muammer Özkan; Derya Burcu Özkan; Orkun Özener; Hasan Yılmaz. 2013. "Experimental study on energy and exergy analyses of a diesel engine performed with multiple injection strategies: Effect of pre-injection timing." Applied Thermal Engineering 53, no. 1: 21-30.

Journal article
Published: 01 January 2013 in Thermal Science
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This study details the artificial neural network (ANN) modelling of a diesel engine to predict the torque, power, brake-specific fuel consumption and pollutant emissions, including carbon dioxide, carbon monoxide, nitrogen oxides, total hydrocarbons and filter smoke number. To collect data for training and testing the neural network, experiments were performed on a four cylinder, four stroke compression ignition engine. A total of 108 test points were run on a dynamometer. For the first part of this work, a parameter packet was used as the inputs for the neural network, and satisfactory regression was found with the outputs (over ~95%), excluding total hydrocarbons. The second stage of this work addressed developing new networks with additional inputs for predicting the total hydrocarbons, and the regression was raised from 75 % to 90 %. This study shows that the ANN approach can be used for accurately predicting characteristic values of an internal combustion engine and that the neural network performance can be increased using additional related input data

ACS Style

Orkun Özener; Levent Yüksek; Muammer Özkan. Artificial neural network approach to predicting engine-out emissions and performance parameters of a turbo charged diesel engine. Thermal Science 2013, 17, 153 -166.

AMA Style

Orkun Özener, Levent Yüksek, Muammer Özkan. Artificial neural network approach to predicting engine-out emissions and performance parameters of a turbo charged diesel engine. Thermal Science. 2013; 17 (1):153-166.

Chicago/Turabian Style

Orkun Özener; Levent Yüksek; Muammer Özkan. 2013. "Artificial neural network approach to predicting engine-out emissions and performance parameters of a turbo charged diesel engine." Thermal Science 17, no. 1: 153-166.

Research article
Published: 01 November 2007 in Energy & Fuels
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In this study, a compression ignition (CI) engine designed for diesel fuel was operated using biodiesel. No alteration was made to the fuel system or settings of the CI engine during tests. The changes in engine performance, emissions, and cycle by cycle (CBC) variations were observed, and their causes were studied. When biodiesel was used as the fuel, acceptable changes occurred in the performance values. The maximum brake mean effective pressure (BMEP) obtained with the biodiesel was 16% lower than that obtained with the diesel fuel, with the difference being 7.5% under maximum power. While biodiesel reduced the maximum engine power by 8.6%, it increased the brake specific fuel consumption by 9.6%. A comparison of exhaust emissions showed that CO emissions of biodiesel are lower than those of diesel fuel. The difference between the obtained minimum values was around 70%. In terms of hydrocarbon (HC) emissions, diesel fuel has produced better results than the biodiesel fuel. Biodiesel resulted in higher NO x emissions than diesel fuel when the engine operation range was considered. The difference was about 13–15% in the maximum power region. The coefficient of variation of ignition delay of both fuels had similar characteristics. However, due to the difference in the cetane numbers, the ignition delay period of biodiesel was longer. Changes of maximum cylinder pressure have occurred at the same magnitude for both fuels for the same engine speeds. The coefficient of variation of maximum cylinder pressure for both fuels had similar characteristics and considerably increased under maximum power conditions.

ACS Style

Muammer Özkan. Comparative Study of the Effect of Biodiesel and Diesel Fuel on a Compression Ignition Engine’s Performance, Emissions, and Its Cycle by Cycle Variations. Energy & Fuels 2007, 21, 3627 -3636.

AMA Style

Muammer Özkan. Comparative Study of the Effect of Biodiesel and Diesel Fuel on a Compression Ignition Engine’s Performance, Emissions, and Its Cycle by Cycle Variations. Energy & Fuels. 2007; 21 (6):3627-3636.

Chicago/Turabian Style

Muammer Özkan. 2007. "Comparative Study of the Effect of Biodiesel and Diesel Fuel on a Compression Ignition Engine’s Performance, Emissions, and Its Cycle by Cycle Variations." Energy & Fuels 21, no. 6: 3627-3636.

Journal article
Published: 01 January 2005 in International Journal of Environment and Pollution
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In this study, low pressure systems have been applied for exhaust gas recycling (EGR), which is applied in certain operating conditions. Induction air, exhaust gas flow, amount of exhaust gas added to the induction air, amount of carbon dioxide (CO

ACS Style

Muammer Özkan; Tarkan Sandalcı; Derya B. Ozkan. Comparison of EGR ratios determined by four different methods for electronic re-circulation gate control. International Journal of Environment and Pollution 2005, 23, 223 .

AMA Style

Muammer Özkan, Tarkan Sandalcı, Derya B. Ozkan. Comparison of EGR ratios determined by four different methods for electronic re-circulation gate control. International Journal of Environment and Pollution. 2005; 23 (2):223.

Chicago/Turabian Style

Muammer Özkan; Tarkan Sandalcı; Derya B. Ozkan. 2005. "Comparison of EGR ratios determined by four different methods for electronic re-circulation gate control." International Journal of Environment and Pollution 23, no. 2: 223.

Journal article
Published: 01 January 2002 in International Journal of Environment and Pollution
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The clearance volume between the piston, the cylinder and the top compression ring in an internal combustion engine has a significant effect on the unburned hydrocarbon concentration. The high heat transfer from the burning mixture to the cylinder surface extinguishes the flame front, and this is the main reason for increased unburned hydrocarbon concentrations. The heat transfer between the mixture and the clearance volume surface is affected by the ratio of coolant surface to the clearance volume. In this study the effect of the ratio of the coolant surface to the clearance volume on the unburned hydrocarbon concentration was investigated using three different purpose-built pistons. A decrease of this ratio reduced the unburned hydrocarbon concentration by 40%.

ACS Style

Muammer Özkan; Orhan Deniz; Tarkan Sandalcı. Experimental study of the effect of top-ring clearance volume on unburned hydrocarbon concentrations. International Journal of Environment and Pollution 2002, 18, 197 .

AMA Style

Muammer Özkan, Orhan Deniz, Tarkan Sandalcı. Experimental study of the effect of top-ring clearance volume on unburned hydrocarbon concentrations. International Journal of Environment and Pollution. 2002; 18 (2):197.

Chicago/Turabian Style

Muammer Özkan; Orhan Deniz; Tarkan Sandalcı. 2002. "Experimental study of the effect of top-ring clearance volume on unburned hydrocarbon concentrations." International Journal of Environment and Pollution 18, no. 2: 197.