Panagiotis Kontoulis | National Technical University of Athens (original) (raw)

Uploads

Papers by Panagiotis Kontoulis

Research paper thumbnail of Effects of Fuel Post-Injection on the Performance and Pollutant Emissions of a Large Marine Engine

Journal of Energy Engineering, 2016

Research paper thumbnail of Investigation of Fuel Injection Strategies for Partially Premixed Compression Ignition Combustion in Two-Stroke Marine Diesel Engines

The implementation of multiple-injection strategies in marine Diesel engines may partially contri... more The implementation of multiple-injection strategies in marine Diesel engines may partially contribute to compliance with emission regulations, while also maintaining a high engine performance. The present computational study investigates the possibility of implementing Partially Premixed Compression Ignition (PPCI) combustion in two-stroke marine Diesel engines. In particular, the concept is implemented in terms of pilot fuel injection with proper orientation of the spray jets, and tested by Computational Fluid Dynamics (CFD) simulations in a large two-stroke marine Diesel engine operating at full load. An early fuel injection is accompanied by long ignition delay, thus allowing fuel-air premixing.

Research paper thumbnail of A new model for marine Heavy Fuel Oil thermophysical properties: validation in a constant volume spray chamber

Heavy Fuel Oil (HFO) is widely used in marine propulsion. Marine HFOs are blending products of re... more Heavy Fuel Oil (HFO) is widely used in marine propulsion. Marine HFOs are blending products of residue and light fractions, and are commonly referred to as Intermediate Fuel Oils (IFOs). In Computational Fluid Dynamics (CFD) studies, physical model performance depends critically on the accuracy of fuel property values. In this context, a new detailed model for calculating IFO thermophysical properties has been developed in the present work. The new model considers IFO as an equivalent one-component heavy petroleum fraction with undefined composition, while the required input is four values of fuel properties, commonly measured at fuel bunkering, namely: (a) density at 288.15 K, (b-c) kinematic viscosity values at 288.15 K and 323.15 K, (d) sulphur weight content. Here, the thermophysical properties of four widely used marine heavy fuel grades, namely IFO 700/RMK, IFO 500/RMK, IFO 380/RMK and IFO 180/RMG, as prescribed by the ISO 8217:2010, are calculated, validating the new model. Further, the model is tested with CFD simulations of non-reactive spray flow in a large constant volume chamber; the results are in good agreement with recent experiments. The present results are deemed very promising, yielding a solid basis for CFD studies of HFO combustion in marine Diesel engines.

Research paper thumbnail of CFD and experimental studies of Heavy Fuel Oil sprays for marine engine applications

A major development for experimental studies in the context of marine Diesel engines was achieved... more A major development for experimental studies in the context of marine Diesel engines was achieved in the course of the EU funded research project HERCULES (High-Efficiency R&D on Combustion with Ultra Low Emissions for Ships). In particular, a state-of-the-art experimental test facility, dedicated to spray and combustion studies under conditions similar to those of large marine Diesel engines, was developed by Wärtsilä Switzerland and ETH Zürich. This Spray Combustion Chamber (SCC) facility enables detailed flow, spray, combustion and emission formation studies. Thus, valuable experimental data can be attained for characterizing spray and combustion, as well as for validating and supporting model development for Computational Fluid Dynamics (CFD) studies.

Research paper thumbnail of Evaluation of Pilot Injections in a Large Two-Stroke Marine Diesel Engine, Using CFD and T-φ Mapping

In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions... more In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions from seagoing ships. The strategy reports on the magnitude and impact of ship emissions in the EU, and sets out a number of actions to reduce the contribution of shipping to health and climate change. One possible approach for the reduction of NO X and soot emissions of marine diesel engines is the use of multiple injection strategies, similar to the ones used in automotive diesel engines. In this way, diesel combustion could be optimized with respect to pollutant emissions, without compromising fuel efficiency.

Research paper thumbnail of Analysis of Combustion and Emissions in a Large Two-Stroke Marine Diesel Engine, Using CFD and T-φ Mapping INTRODUCTION

In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions... more In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions from seagoing ships. The strategy reports on the magnitude and impact of ship emissions in the EU, and sets out a number of actions to reduce the contribution of shipping to health and climate change. One possible approach for the reduction of NO X and soot emissions of marine diesel engines is the use of multiple injection strategies, similar to the ones used in automotive diesel engines. In this way, diesel combustion could be optimized with respect to pollutant emissions, without compromising fuel efficiency.

Research paper thumbnail of Effects of Fuel Post-Injection on the Performance and Pollutant Emissions of a Large Marine Engine

Journal of Energy Engineering, 2016

Research paper thumbnail of Investigation of Fuel Injection Strategies for Partially Premixed Compression Ignition Combustion in Two-Stroke Marine Diesel Engines

The implementation of multiple-injection strategies in marine Diesel engines may partially contri... more The implementation of multiple-injection strategies in marine Diesel engines may partially contribute to compliance with emission regulations, while also maintaining a high engine performance. The present computational study investigates the possibility of implementing Partially Premixed Compression Ignition (PPCI) combustion in two-stroke marine Diesel engines. In particular, the concept is implemented in terms of pilot fuel injection with proper orientation of the spray jets, and tested by Computational Fluid Dynamics (CFD) simulations in a large two-stroke marine Diesel engine operating at full load. An early fuel injection is accompanied by long ignition delay, thus allowing fuel-air premixing.

Research paper thumbnail of A new model for marine Heavy Fuel Oil thermophysical properties: validation in a constant volume spray chamber

Heavy Fuel Oil (HFO) is widely used in marine propulsion. Marine HFOs are blending products of re... more Heavy Fuel Oil (HFO) is widely used in marine propulsion. Marine HFOs are blending products of residue and light fractions, and are commonly referred to as Intermediate Fuel Oils (IFOs). In Computational Fluid Dynamics (CFD) studies, physical model performance depends critically on the accuracy of fuel property values. In this context, a new detailed model for calculating IFO thermophysical properties has been developed in the present work. The new model considers IFO as an equivalent one-component heavy petroleum fraction with undefined composition, while the required input is four values of fuel properties, commonly measured at fuel bunkering, namely: (a) density at 288.15 K, (b-c) kinematic viscosity values at 288.15 K and 323.15 K, (d) sulphur weight content. Here, the thermophysical properties of four widely used marine heavy fuel grades, namely IFO 700/RMK, IFO 500/RMK, IFO 380/RMK and IFO 180/RMG, as prescribed by the ISO 8217:2010, are calculated, validating the new model. Further, the model is tested with CFD simulations of non-reactive spray flow in a large constant volume chamber; the results are in good agreement with recent experiments. The present results are deemed very promising, yielding a solid basis for CFD studies of HFO combustion in marine Diesel engines.

Research paper thumbnail of CFD and experimental studies of Heavy Fuel Oil sprays for marine engine applications

A major development for experimental studies in the context of marine Diesel engines was achieved... more A major development for experimental studies in the context of marine Diesel engines was achieved in the course of the EU funded research project HERCULES (High-Efficiency R&D on Combustion with Ultra Low Emissions for Ships). In particular, a state-of-the-art experimental test facility, dedicated to spray and combustion studies under conditions similar to those of large marine Diesel engines, was developed by Wärtsilä Switzerland and ETH Zürich. This Spray Combustion Chamber (SCC) facility enables detailed flow, spray, combustion and emission formation studies. Thus, valuable experimental data can be attained for characterizing spray and combustion, as well as for validating and supporting model development for Computational Fluid Dynamics (CFD) studies.

Research paper thumbnail of Evaluation of Pilot Injections in a Large Two-Stroke Marine Diesel Engine, Using CFD and T-φ Mapping

In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions... more In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions from seagoing ships. The strategy reports on the magnitude and impact of ship emissions in the EU, and sets out a number of actions to reduce the contribution of shipping to health and climate change. One possible approach for the reduction of NO X and soot emissions of marine diesel engines is the use of multiple injection strategies, similar to the ones used in automotive diesel engines. In this way, diesel combustion could be optimized with respect to pollutant emissions, without compromising fuel efficiency.

Research paper thumbnail of Analysis of Combustion and Emissions in a Large Two-Stroke Marine Diesel Engine, Using CFD and T-φ Mapping INTRODUCTION

In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions... more In 2002 the European Commission adopted a European Union strategy to reduce atmospheric emissions from seagoing ships. The strategy reports on the magnitude and impact of ship emissions in the EU, and sets out a number of actions to reduce the contribution of shipping to health and climate change. One possible approach for the reduction of NO X and soot emissions of marine diesel engines is the use of multiple injection strategies, similar to the ones used in automotive diesel engines. In this way, diesel combustion could be optimized with respect to pollutant emissions, without compromising fuel efficiency.