Carmen MATA - Academia.edu (original) (raw)

Papers by Carmen MATA

Research paper thumbnail of Effect of diesel injection parameters on instantaneous fuel delivery using a solenoid- operated injector with different fuels Efecto de parámetros de inyección diesel sobre la entrega instantánea de combustible usando un inyector de bobina electromagnética con diferentes combustibles

Research paper thumbnail of Experimental determination and modelling of fuel rate of injection: A review

Research paper thumbnail of Performance and regulated emissions from a Euro VI-D hybrid bus tested with fossil and renewable (hydrotreated vegetable oil) diesel fuels under urban driving in Bilbao city, Spain

Journal of Cleaner Production

Research paper thumbnail of Bioethanol-Diesel Blends Used in Diesel Engines and Vehicles under Transient Operation

Bioethanol [Working Title], 2020

This book chapter describes, the experiences of different experimental works related to the study... more This book chapter describes, the experiences of different experimental works related to the study of the effect of bioethanol-diesel fuel blends directly used on a study about the integrity of some parts of a diesel injection system, and on performance and regulated emissions of engines and/or vehicles under different transient conditions. The experiences described are carried out in an engine test bench, two public busses under urban transportation and a construction machine in an actual railway construction. A bioethanol-diesel fuel blend with 10% v/v of bioethanol was used for engine testing to study the potential effect on performance and emissions. Later, a blend with around 8% v/v of alcohol concentration was selected to carry out the experimental work with an injection system and with busses and construction machinery. This work points out the most important advantages and disadvantages of the use of bioethanol blended with diesel fuel. The most important strength is the pote...

Research paper thumbnail of Comparative study of the opacity tendency of alternative diesel fuels blended with gasoline

Fuel, 2020

Abstract New combustion concepts in Diesel engines imply the use of more appropriate fuels for th... more Abstract New combustion concepts in Diesel engines imply the use of more appropriate fuels for this type of combustion than traditional diesel fuel. Low Temperature Combustion (LTC), as Premixed Charge Compression Ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or Reactivity Controlled Compression Ignition (RCCI) concepts, have begun to use Diesel–Gasoline blends because their low cetane number can reduce, simultaneously, NOx and soot emissions and also improve thermal efficiency. However, new cleaner fuels, alternative to conventional fossil Diesel can also be a solution. In this work, the sooting tendency of Diesel–Gasoline blends was compared to three binary alternative fuels blended with Gasoline: a Biodiesel, a Gas–To–Liquid (GTL) and a new renewable paraffinic fuel called Farnesane. The Oxygen Extended Sooting Index (OESI) was chosen as an appropriate parameter for opacity tendency comparison. Results show that, for the same Gasoline percentage, the sooting tendency scales as follows: Farnesane = GTL

Research paper thumbnail of Comparative study of the effect of a new renewable paraffinic fuel on the combustion process of a light-duty diesel engine

Energy, 2019

The effect of a new renewable paraffinic fuel on the combustion characteristics of a diesel engin... more The effect of a new renewable paraffinic fuel on the combustion characteristics of a diesel engine was evaluated and compared to other fossil paraffinic fuel (GTL e Gas-To Liquid), to a Biodiesel (blend of soybean and palm oil) and a to a conventional fossil diesel (without Biodiesel). Five steady state modes were selected that cover the most part of the engine speed-torque map of the driving conditions established in the New European Driving Cycle (NEDC). At the lowest engine load modes (A and C), the start of heat release occurs after main injection but at the other three modes (E, G and I) thermal conditions favor combustion of the pre-injection, the start of combustion escalating with the cetane number of the fuels. Biodiesel shows the lowest combustion duration, being the behavior of Farnesane similar only at high engine load conditions. Although Farnesane and GTL are paraffinic fuels, the combustion duration with the biofuel is more than 5 shorter in modes G and I although its start of combustion takes place earlier.

Research paper thumbnail of Particles emitted during the stops of an urban bus fuelled with ethanol–biodiesel–diesel blends

Urban Climate, 2012

Urban buses with diesel engines produce NOx and particulate matter emissions thus affecting local... more Urban buses with diesel engines produce NOx and particulate matter emissions thus affecting local city pollution. During stops, due to traffic lights, programmed stops, etc., pollutants are emitted close to people, being damaging to their health. This paper studies the effects on particle size distributions caused by the use of oxygenated fuels during stops of an urban bus. Fuels used are a blend of ethanol and diesel (denoted as ED) and a blend of ethanol, biodiesel and diesel (denoted as EBD), which are compared to a diesel fuel used as reference. Tests were carried out on a vehicle under real working conditions in the Spanish city of Seville. A Horiba 1300 on-board system (OBS) was used to measure operating conditions, and an Engine Exhaust Particle Sizer Spectrometer was used to determine particle size distributions. Results showed a reduction in the number concentration of accumulation mode when oxygenated fuels were used. However, they produced a slight increase in the nuclei mode, as well as a reduction in particle diameters from both modes when using EBD blends, being more significant when referring to accumulation mode. These findings may be considered negative for the oxygenated blends under these operating conditions.

Research paper thumbnail of sj-pdf-1-jer-10.1177_1468087421996525 – Supplemental material for Impact of alternative and fossil diesel fuels on internal flow of injection nozzle

Supplemental material, sj-pdf-1-jer-10.1177_1468087421996525 for Impact of alternative and fossil... more Supplemental material, sj-pdf-1-jer-10.1177_1468087421996525 for Impact of alternative and fossil diesel fuels on internal flow of injection nozzle by Francisco J Martos, José A Soriano, Carmen Mata, Octavio Armas and Felipe Soto in International Journal of Engine Research

Research paper thumbnail of Comparison of real driving emissions from Euro VI buses with diesel and compressed natural gas fuels

Fuel, 2021

Public transport bus service is extended in big cities and cleaner bus fleets are encouraged to r... more Public transport bus service is extended in big cities and cleaner bus fleets are encouraged to reduce greenhouse and air pollutant emissions in high populated areas. In this work, real driving emissions produced by two Euro VI-C buses, one fueled by diesel fuel and one fueled by compressed natural gas, were measured. Both vehicles with different engine technologies but with the same pollutant emission certification, were tested in Madrid (Spain), in order to compare their emissions under the same route. The buses were instrumented with a modular on-board Portable Emissions Measurement System, the OBS-ONE by Horiba. Regulated gaseous emissions and particle number were registered together with different vehicle parameters: speed, exhaust mass flow rate, air and fuel consumption, environmental conditions and global position coordinates during the route. THC emissions from CNG bus doubled those obtained with Diesel bus. Slightly higher NO x emissions from the Diesel bus, with selective catalytic reduction, were obtained during those parts of the circuits (mainly urban) where both the exhaust and the operation temperature of the after-treatment device were below the light-off temperature. However, the CNG bus emitted a greater number of particles, mainly on the rural sector of the circuit. Finally, NO x and particle number concentrations along the route showed that traffic is a determining factor in creating areas with high concentrations of pollutants.

Research paper thumbnail of Effect of the In-Cylinder Back Pressure on the Injection Process and Fuel Flow Characteristics in a Common-Rail Diesel Injector Using GTL Fuel

Energies, 2021

The presented paper aims to study the influence of mineral diesel fuel and synthetic Gas-To-Liqui... more The presented paper aims to study the influence of mineral diesel fuel and synthetic Gas-To-Liquid fuel (GTL) on the injection process, fuel flow conditions, and cavitation formation in a modern common-rail injector. First, the influence on injection characteristics was studied experimentally using an injection system test bench, and numerically using the one-dimensional computational program. Afterward, the influence of fuel properties on internal fuel flow was studied numerically using a computational program. The flow inside the injector was considered as multiphase flow and was calculated through unsteady Computational Fluid Dynamics simulations using a Eulerian–Eulerian two-fluid approach. Finally, the influence of in-cylinder back pressure on the internal nozzle flow was studied at three distinctive back pressures. The obtained numerical results for injection characteristics show good agreement with the experimental ones. The results of 3D simulations indicate that differences...

Research paper thumbnail of Implantación de práctica docente para la recuperación de energía eléctrica usando termoeléctricos

Research paper thumbnail of Design of Laboratory Practice for Observation of Parts with a Digital Microscope

EDULEARN18 Proceedings, 2018

Research paper thumbnail of Simulation of Optimal Driving for Minimization of Fuel Consumption or NOx Emissions in a Diesel Vehicle

Energies, 2021

Significant reduction in fuel consumption and NOx emissions can be achieved just by changing the ... more Significant reduction in fuel consumption and NOx emissions can be achieved just by changing the driving along the road. In this paper, dynamic programming is employed to find two different driving profiles optimized for fuel consumption and NOx creation minimization in a diesel vehicle. Results, show that the fuel reduction driving cycle leads to fuel savings of 4% compared with the average consumption with arbitrary driving. The NOx reduction driving profile improves the emissions of arbitrary driving by a 34.5%. NOx oriented driving profile improves the emissions of the fuel-oriented cycle by a 38% at the expense of a fuel consumption penalty of 10%. This result points out the difficulty of a simultaneous NOx and fuel consumption reduction, stressing the efforts to be done in this field during the following years. Strategies followed and conclusions drawn from this paper are relevant concerning vehicle autonomy integration.

Research paper thumbnail of Impact of alternative and fossil diesel fuels on internal flow of injection nozzle

International Journal of Engine Research, 2021

This work presents a computational study about the effect of different fossil fuels (Diesel and G... more This work presents a computational study about the effect of different fossil fuels (Diesel and GTL) and renewable (Farnesane and Biodiesel) on the characteristics of the nozzle fuel internal flow (speed flow, cavitation, mass flow rate and discharge coefficient). This investigation was focused on the pass of fuel from the volume around the tip of the injector needle to the nozzle holes. Several engine-operating conditions, characteristic of urban driving conditions, were tested. These conditions, characterized by their injection pressure and injection timing as well as the experimental rates of fuel injected, were simulated with all mentioned fuels. Solenoid operated seven holes injector, 0.15 mm orifice diameter was used. Results show the effect of fuel origin on the internal flow along the nozzle orifice of the injector. Among the results obtained are the following: at medium load the effect of the needle lift on the cavitation generation is more significant than the fluid circul...

Research paper thumbnail of Impact of regulated pollutant emissions of Euro 6d-Temp light-duty diesel vehicles under real driving conditions

Journal of Cleaner Production, 2021

The inclusion of the measurement of pollutant emissions under real driving conditions for the veh... more The inclusion of the measurement of pollutant emissions under real driving conditions for the vehicle certification, together with the restrictive limits in environmental regulations, has motivated an improvement of active and passive pollution control technologies in order to reduce pollution under both urban and extra-urban conditions. In this work, two Euro 6d-Temp diesel passenger cars, classified in different segments, a C-segment and a Sport Utility Vehicle (SUV), were tested along a route selected considering the Real Driving Emissions (RDE) test procedure. The tests were carried out in Madrid (Spain), a city with almost 3.3 million of inhabitants and a metropolitan area population of approximately 6.5 million with almost 5 million of vehicles. This work aims to study the contribution of the new generation diesel light-duty vehicles on the urban air quality. Results show great effectiveness of pollution control technologies, since the results of NOx emissions registered were 60% and 76% lower, with the SUV and C-segment vehicle, respectively, than limits established in Euro 6d-Temp regulation. In the case of PN emissions this reduction is even higher, 99% and 88% with SUV and C-segment vehicle, respectively. The opposite trends between NOx and PN for both vehicles revealed the different effectiveness of the pollution control strategies. This work also presents the distribution of emissions along the circuit, identifying the zones more affected regarding the pollution produced by both vehicles.

Research paper thumbnail of Impact of Alternative Paraffinic Fuels on the Durability of a Modern Common Rail Injection System

Energies, 2020

Common rail (CR) diesel fuel injection systems are very sensitive to variations in fuel propertie... more Common rail (CR) diesel fuel injection systems are very sensitive to variations in fuel properties, thus the impact of alternative fuels on the durability of the injection system should be investigated when considering the use of alternative fuels. This work studies a high-pressure CR (HPCR) diesel fuel injection system operating for 400 h in an injection test bench, using a fuel blend composed of an alternative paraffinic fuel and conventional diesel (50PF50D). The alternative fuel does not have aromatic components and has lower density than conventional diesel fuel. The injection system durability study was carried out under typical injection pressure and fuel temperature for the fuel pump, the common rail and the injector. The results show that the HPCR fuel injection system and its components (e.g., piston, spring, cylinder, driveshaft and cam) have no indication of damage, wear or change in surface roughness. The absence of internal wear to the components of the injection syste...

Research paper thumbnail of Rate of injection measurements of a direct-acting piezoelectric injector for different operating temperatures

Energy Conversion and Management, 2017

As the regulations for pollutant emissions in diesel engines are increasingly restrictive, the in... more As the regulations for pollutant emissions in diesel engines are increasingly restrictive, the introduction of the piezoelectric direct-acting injectors seeks to improve the overall efficiency of the injection system, and consequently reduce combustion contaminants. In such systems, the needle lift is governed by the charge, or voltage, applied to the piezo stack, allowing for a more precise control over the fuel injection process. Although it is known that the performance of the piezoelectric crystals depends on its temperature of operation, the effect this has on the rate of injection is still unclear. In this research, a particular setup was used to measure the rate of injection of a direct-acting injector for different operating temperatures. It was mounted into an injection discharge rate curve indicator with a particular holder that has a cooling sleeve connected to a circuit running ethylene glycol, which is driven by a thermoregulator unit. A parametric sweep of different piezo stack control voltages for three rail pressures and operating temperatures was carried out. On the results, when needle lift does not influence internal flow development, the rate of injection was controlled by the injection pressure, with minimal impact from the working temperature, resembling results from conventional hydraulic injectors. At partial needle lift, two operating regions were observed, delimited by a particular voltage level. Above it, the needle throttling was able to control mass fuel flow accurately. But below it, the stabilized rate of injection values decreased drastically. The rate of this decline was dependent only on the injection pressure. The threshold level, named critical voltage, increased linearly with increasing injection pressure and working temperature. Also, to maintain a constant fuel mass flow for decreasing operating temperature, the voltage level of the control signal had to be reduced. These results highlight the importance of monitoring and controlling the operating conditions of the direct-acting injectors, as their performance and efficiency are both influenced by the working temperature of the piezo stack.

Research paper thumbnail of The influence of ethanol-diesel blend on pollutant emissions from different bus fleets under acceleration transitions

Fuel, 2017

Main pollutant emissions produced by urban diesel buses are nitrogen oxides and particulate matte... more Main pollutant emissions produced by urban diesel buses are nitrogen oxides and particulate matter. Moreover, it is well known that level of emissions produced under real world driving conditions can be very different compared to those obtained under dyno-chassis tests or engine tests. The causes of these differences can be due to several sources such as operating conditions at various temperatures and pressures, different ground roughness, slopes, driver effect, change of gears or traffic. This work studies the effect of two different fuels on nitrogen oxides and particle size distributions under real world driving sequences of vehicle acceleration. Fuels tested were a low sulfur Diesel fuel (without biodiesel) and a binary ethanol-diesel fuel blend. This work was done with two models of similar buses, each one operating in cities located at different altitudes. Results show a reduction in particle concentration when ethanol-diesel blend was used. Mean geometric diameters decreased when ethanol-diesel was used. Concerning nitrogen oxides emissions, different trends were observed between vehicles depending on the transient sequence and the fuel used. Ethanol-diesel fuel blend reduces NO x at high altitude, but increases at low altitude. All results were probably affected by the altitude of the cities more than by the vehicle model itself.

Research paper thumbnail of Impact of Gas To Liquid and diesel fuels on the engine cold start

Fuel, 2017

h i g h l i g h t s Gas To Liquid and diesel fuels were tested under cold engine start conditions... more h i g h l i g h t s Gas To Liquid and diesel fuels were tested under cold engine start conditions. A methodology to evaluate different parameters from thermodynamic diagnosis has been developed. Parameters derived from on-line thermodynamic diagnosis have been studied. Clear effect of the engine coolant temperature on the rate of apparent heat release has been observed. The effect of cetane number is notable at low cold start temperatures.

Research paper thumbnail of Prediction of NOx Emissions and Fuel Consumption of a City Bus under Real Operating Conditions by Means of Biharmonic Maps

Journal of Energy Engineering, 2016

AbstractThe prediction of pollutant emissions and fuel consumption under real operating condition... more AbstractThe prediction of pollutant emissions and fuel consumption under real operating conditions of any motor vehicle requires the use of complex mathematical models and experimental tools. In the present research, biharmonic maps (BM) were used to predict NOx (nitrogen oxides) emissions and relative fuel–air ratio (Fr) of a passenger city bus. For the collection of experimental data, an instrumented city bus was tested during real passenger transportation. The data were classified into four dynamic sequences: acceleration, idling, deceleration with fuel consumption, and deceleration without fuel consumption. Among them, the acceleration sequence was selected due to high NOx emissions and high fuel consumption. Experimental results were in good agreement with BM predictions. Significant parameters for predicting NOx concentration were vehicle velocity and relative fuel–air ratio (Fr). While for predicting Fr, significant parameters were the exhaust gas flow (EGF) rate, vehicle velocity, and NOx concentr...

Research paper thumbnail of Effect of diesel injection parameters on instantaneous fuel delivery using a solenoid- operated injector with different fuels Efecto de parámetros de inyección diesel sobre la entrega instantánea de combustible usando un inyector de bobina electromagnética con diferentes combustibles

Research paper thumbnail of Experimental determination and modelling of fuel rate of injection: A review

Research paper thumbnail of Performance and regulated emissions from a Euro VI-D hybrid bus tested with fossil and renewable (hydrotreated vegetable oil) diesel fuels under urban driving in Bilbao city, Spain

Journal of Cleaner Production

Research paper thumbnail of Bioethanol-Diesel Blends Used in Diesel Engines and Vehicles under Transient Operation

Bioethanol [Working Title], 2020

This book chapter describes, the experiences of different experimental works related to the study... more This book chapter describes, the experiences of different experimental works related to the study of the effect of bioethanol-diesel fuel blends directly used on a study about the integrity of some parts of a diesel injection system, and on performance and regulated emissions of engines and/or vehicles under different transient conditions. The experiences described are carried out in an engine test bench, two public busses under urban transportation and a construction machine in an actual railway construction. A bioethanol-diesel fuel blend with 10% v/v of bioethanol was used for engine testing to study the potential effect on performance and emissions. Later, a blend with around 8% v/v of alcohol concentration was selected to carry out the experimental work with an injection system and with busses and construction machinery. This work points out the most important advantages and disadvantages of the use of bioethanol blended with diesel fuel. The most important strength is the pote...

Research paper thumbnail of Comparative study of the opacity tendency of alternative diesel fuels blended with gasoline

Fuel, 2020

Abstract New combustion concepts in Diesel engines imply the use of more appropriate fuels for th... more Abstract New combustion concepts in Diesel engines imply the use of more appropriate fuels for this type of combustion than traditional diesel fuel. Low Temperature Combustion (LTC), as Premixed Charge Compression Ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or Reactivity Controlled Compression Ignition (RCCI) concepts, have begun to use Diesel–Gasoline blends because their low cetane number can reduce, simultaneously, NOx and soot emissions and also improve thermal efficiency. However, new cleaner fuels, alternative to conventional fossil Diesel can also be a solution. In this work, the sooting tendency of Diesel–Gasoline blends was compared to three binary alternative fuels blended with Gasoline: a Biodiesel, a Gas–To–Liquid (GTL) and a new renewable paraffinic fuel called Farnesane. The Oxygen Extended Sooting Index (OESI) was chosen as an appropriate parameter for opacity tendency comparison. Results show that, for the same Gasoline percentage, the sooting tendency scales as follows: Farnesane = GTL

Research paper thumbnail of Comparative study of the effect of a new renewable paraffinic fuel on the combustion process of a light-duty diesel engine

Energy, 2019

The effect of a new renewable paraffinic fuel on the combustion characteristics of a diesel engin... more The effect of a new renewable paraffinic fuel on the combustion characteristics of a diesel engine was evaluated and compared to other fossil paraffinic fuel (GTL e Gas-To Liquid), to a Biodiesel (blend of soybean and palm oil) and a to a conventional fossil diesel (without Biodiesel). Five steady state modes were selected that cover the most part of the engine speed-torque map of the driving conditions established in the New European Driving Cycle (NEDC). At the lowest engine load modes (A and C), the start of heat release occurs after main injection but at the other three modes (E, G and I) thermal conditions favor combustion of the pre-injection, the start of combustion escalating with the cetane number of the fuels. Biodiesel shows the lowest combustion duration, being the behavior of Farnesane similar only at high engine load conditions. Although Farnesane and GTL are paraffinic fuels, the combustion duration with the biofuel is more than 5 shorter in modes G and I although its start of combustion takes place earlier.

Research paper thumbnail of Particles emitted during the stops of an urban bus fuelled with ethanol–biodiesel–diesel blends

Urban Climate, 2012

Urban buses with diesel engines produce NOx and particulate matter emissions thus affecting local... more Urban buses with diesel engines produce NOx and particulate matter emissions thus affecting local city pollution. During stops, due to traffic lights, programmed stops, etc., pollutants are emitted close to people, being damaging to their health. This paper studies the effects on particle size distributions caused by the use of oxygenated fuels during stops of an urban bus. Fuels used are a blend of ethanol and diesel (denoted as ED) and a blend of ethanol, biodiesel and diesel (denoted as EBD), which are compared to a diesel fuel used as reference. Tests were carried out on a vehicle under real working conditions in the Spanish city of Seville. A Horiba 1300 on-board system (OBS) was used to measure operating conditions, and an Engine Exhaust Particle Sizer Spectrometer was used to determine particle size distributions. Results showed a reduction in the number concentration of accumulation mode when oxygenated fuels were used. However, they produced a slight increase in the nuclei mode, as well as a reduction in particle diameters from both modes when using EBD blends, being more significant when referring to accumulation mode. These findings may be considered negative for the oxygenated blends under these operating conditions.

Research paper thumbnail of sj-pdf-1-jer-10.1177_1468087421996525 – Supplemental material for Impact of alternative and fossil diesel fuels on internal flow of injection nozzle

Supplemental material, sj-pdf-1-jer-10.1177_1468087421996525 for Impact of alternative and fossil... more Supplemental material, sj-pdf-1-jer-10.1177_1468087421996525 for Impact of alternative and fossil diesel fuels on internal flow of injection nozzle by Francisco J Martos, José A Soriano, Carmen Mata, Octavio Armas and Felipe Soto in International Journal of Engine Research

Research paper thumbnail of Comparison of real driving emissions from Euro VI buses with diesel and compressed natural gas fuels

Fuel, 2021

Public transport bus service is extended in big cities and cleaner bus fleets are encouraged to r... more Public transport bus service is extended in big cities and cleaner bus fleets are encouraged to reduce greenhouse and air pollutant emissions in high populated areas. In this work, real driving emissions produced by two Euro VI-C buses, one fueled by diesel fuel and one fueled by compressed natural gas, were measured. Both vehicles with different engine technologies but with the same pollutant emission certification, were tested in Madrid (Spain), in order to compare their emissions under the same route. The buses were instrumented with a modular on-board Portable Emissions Measurement System, the OBS-ONE by Horiba. Regulated gaseous emissions and particle number were registered together with different vehicle parameters: speed, exhaust mass flow rate, air and fuel consumption, environmental conditions and global position coordinates during the route. THC emissions from CNG bus doubled those obtained with Diesel bus. Slightly higher NO x emissions from the Diesel bus, with selective catalytic reduction, were obtained during those parts of the circuits (mainly urban) where both the exhaust and the operation temperature of the after-treatment device were below the light-off temperature. However, the CNG bus emitted a greater number of particles, mainly on the rural sector of the circuit. Finally, NO x and particle number concentrations along the route showed that traffic is a determining factor in creating areas with high concentrations of pollutants.

Research paper thumbnail of Effect of the In-Cylinder Back Pressure on the Injection Process and Fuel Flow Characteristics in a Common-Rail Diesel Injector Using GTL Fuel

Energies, 2021

The presented paper aims to study the influence of mineral diesel fuel and synthetic Gas-To-Liqui... more The presented paper aims to study the influence of mineral diesel fuel and synthetic Gas-To-Liquid fuel (GTL) on the injection process, fuel flow conditions, and cavitation formation in a modern common-rail injector. First, the influence on injection characteristics was studied experimentally using an injection system test bench, and numerically using the one-dimensional computational program. Afterward, the influence of fuel properties on internal fuel flow was studied numerically using a computational program. The flow inside the injector was considered as multiphase flow and was calculated through unsteady Computational Fluid Dynamics simulations using a Eulerian–Eulerian two-fluid approach. Finally, the influence of in-cylinder back pressure on the internal nozzle flow was studied at three distinctive back pressures. The obtained numerical results for injection characteristics show good agreement with the experimental ones. The results of 3D simulations indicate that differences...

Research paper thumbnail of Implantación de práctica docente para la recuperación de energía eléctrica usando termoeléctricos

Research paper thumbnail of Design of Laboratory Practice for Observation of Parts with a Digital Microscope

EDULEARN18 Proceedings, 2018

Research paper thumbnail of Simulation of Optimal Driving for Minimization of Fuel Consumption or NOx Emissions in a Diesel Vehicle

Energies, 2021

Significant reduction in fuel consumption and NOx emissions can be achieved just by changing the ... more Significant reduction in fuel consumption and NOx emissions can be achieved just by changing the driving along the road. In this paper, dynamic programming is employed to find two different driving profiles optimized for fuel consumption and NOx creation minimization in a diesel vehicle. Results, show that the fuel reduction driving cycle leads to fuel savings of 4% compared with the average consumption with arbitrary driving. The NOx reduction driving profile improves the emissions of arbitrary driving by a 34.5%. NOx oriented driving profile improves the emissions of the fuel-oriented cycle by a 38% at the expense of a fuel consumption penalty of 10%. This result points out the difficulty of a simultaneous NOx and fuel consumption reduction, stressing the efforts to be done in this field during the following years. Strategies followed and conclusions drawn from this paper are relevant concerning vehicle autonomy integration.

Research paper thumbnail of Impact of alternative and fossil diesel fuels on internal flow of injection nozzle

International Journal of Engine Research, 2021

This work presents a computational study about the effect of different fossil fuels (Diesel and G... more This work presents a computational study about the effect of different fossil fuels (Diesel and GTL) and renewable (Farnesane and Biodiesel) on the characteristics of the nozzle fuel internal flow (speed flow, cavitation, mass flow rate and discharge coefficient). This investigation was focused on the pass of fuel from the volume around the tip of the injector needle to the nozzle holes. Several engine-operating conditions, characteristic of urban driving conditions, were tested. These conditions, characterized by their injection pressure and injection timing as well as the experimental rates of fuel injected, were simulated with all mentioned fuels. Solenoid operated seven holes injector, 0.15 mm orifice diameter was used. Results show the effect of fuel origin on the internal flow along the nozzle orifice of the injector. Among the results obtained are the following: at medium load the effect of the needle lift on the cavitation generation is more significant than the fluid circul...

Research paper thumbnail of Impact of regulated pollutant emissions of Euro 6d-Temp light-duty diesel vehicles under real driving conditions

Journal of Cleaner Production, 2021

The inclusion of the measurement of pollutant emissions under real driving conditions for the veh... more The inclusion of the measurement of pollutant emissions under real driving conditions for the vehicle certification, together with the restrictive limits in environmental regulations, has motivated an improvement of active and passive pollution control technologies in order to reduce pollution under both urban and extra-urban conditions. In this work, two Euro 6d-Temp diesel passenger cars, classified in different segments, a C-segment and a Sport Utility Vehicle (SUV), were tested along a route selected considering the Real Driving Emissions (RDE) test procedure. The tests were carried out in Madrid (Spain), a city with almost 3.3 million of inhabitants and a metropolitan area population of approximately 6.5 million with almost 5 million of vehicles. This work aims to study the contribution of the new generation diesel light-duty vehicles on the urban air quality. Results show great effectiveness of pollution control technologies, since the results of NOx emissions registered were 60% and 76% lower, with the SUV and C-segment vehicle, respectively, than limits established in Euro 6d-Temp regulation. In the case of PN emissions this reduction is even higher, 99% and 88% with SUV and C-segment vehicle, respectively. The opposite trends between NOx and PN for both vehicles revealed the different effectiveness of the pollution control strategies. This work also presents the distribution of emissions along the circuit, identifying the zones more affected regarding the pollution produced by both vehicles.

Research paper thumbnail of Impact of Alternative Paraffinic Fuels on the Durability of a Modern Common Rail Injection System

Energies, 2020

Common rail (CR) diesel fuel injection systems are very sensitive to variations in fuel propertie... more Common rail (CR) diesel fuel injection systems are very sensitive to variations in fuel properties, thus the impact of alternative fuels on the durability of the injection system should be investigated when considering the use of alternative fuels. This work studies a high-pressure CR (HPCR) diesel fuel injection system operating for 400 h in an injection test bench, using a fuel blend composed of an alternative paraffinic fuel and conventional diesel (50PF50D). The alternative fuel does not have aromatic components and has lower density than conventional diesel fuel. The injection system durability study was carried out under typical injection pressure and fuel temperature for the fuel pump, the common rail and the injector. The results show that the HPCR fuel injection system and its components (e.g., piston, spring, cylinder, driveshaft and cam) have no indication of damage, wear or change in surface roughness. The absence of internal wear to the components of the injection syste...

Research paper thumbnail of Rate of injection measurements of a direct-acting piezoelectric injector for different operating temperatures

Energy Conversion and Management, 2017

As the regulations for pollutant emissions in diesel engines are increasingly restrictive, the in... more As the regulations for pollutant emissions in diesel engines are increasingly restrictive, the introduction of the piezoelectric direct-acting injectors seeks to improve the overall efficiency of the injection system, and consequently reduce combustion contaminants. In such systems, the needle lift is governed by the charge, or voltage, applied to the piezo stack, allowing for a more precise control over the fuel injection process. Although it is known that the performance of the piezoelectric crystals depends on its temperature of operation, the effect this has on the rate of injection is still unclear. In this research, a particular setup was used to measure the rate of injection of a direct-acting injector for different operating temperatures. It was mounted into an injection discharge rate curve indicator with a particular holder that has a cooling sleeve connected to a circuit running ethylene glycol, which is driven by a thermoregulator unit. A parametric sweep of different piezo stack control voltages for three rail pressures and operating temperatures was carried out. On the results, when needle lift does not influence internal flow development, the rate of injection was controlled by the injection pressure, with minimal impact from the working temperature, resembling results from conventional hydraulic injectors. At partial needle lift, two operating regions were observed, delimited by a particular voltage level. Above it, the needle throttling was able to control mass fuel flow accurately. But below it, the stabilized rate of injection values decreased drastically. The rate of this decline was dependent only on the injection pressure. The threshold level, named critical voltage, increased linearly with increasing injection pressure and working temperature. Also, to maintain a constant fuel mass flow for decreasing operating temperature, the voltage level of the control signal had to be reduced. These results highlight the importance of monitoring and controlling the operating conditions of the direct-acting injectors, as their performance and efficiency are both influenced by the working temperature of the piezo stack.

Research paper thumbnail of The influence of ethanol-diesel blend on pollutant emissions from different bus fleets under acceleration transitions

Fuel, 2017

Main pollutant emissions produced by urban diesel buses are nitrogen oxides and particulate matte... more Main pollutant emissions produced by urban diesel buses are nitrogen oxides and particulate matter. Moreover, it is well known that level of emissions produced under real world driving conditions can be very different compared to those obtained under dyno-chassis tests or engine tests. The causes of these differences can be due to several sources such as operating conditions at various temperatures and pressures, different ground roughness, slopes, driver effect, change of gears or traffic. This work studies the effect of two different fuels on nitrogen oxides and particle size distributions under real world driving sequences of vehicle acceleration. Fuels tested were a low sulfur Diesel fuel (without biodiesel) and a binary ethanol-diesel fuel blend. This work was done with two models of similar buses, each one operating in cities located at different altitudes. Results show a reduction in particle concentration when ethanol-diesel blend was used. Mean geometric diameters decreased when ethanol-diesel was used. Concerning nitrogen oxides emissions, different trends were observed between vehicles depending on the transient sequence and the fuel used. Ethanol-diesel fuel blend reduces NO x at high altitude, but increases at low altitude. All results were probably affected by the altitude of the cities more than by the vehicle model itself.

Research paper thumbnail of Impact of Gas To Liquid and diesel fuels on the engine cold start

Fuel, 2017

h i g h l i g h t s Gas To Liquid and diesel fuels were tested under cold engine start conditions... more h i g h l i g h t s Gas To Liquid and diesel fuels were tested under cold engine start conditions. A methodology to evaluate different parameters from thermodynamic diagnosis has been developed. Parameters derived from on-line thermodynamic diagnosis have been studied. Clear effect of the engine coolant temperature on the rate of apparent heat release has been observed. The effect of cetane number is notable at low cold start temperatures.

Research paper thumbnail of Prediction of NOx Emissions and Fuel Consumption of a City Bus under Real Operating Conditions by Means of Biharmonic Maps

Journal of Energy Engineering, 2016

AbstractThe prediction of pollutant emissions and fuel consumption under real operating condition... more AbstractThe prediction of pollutant emissions and fuel consumption under real operating conditions of any motor vehicle requires the use of complex mathematical models and experimental tools. In the present research, biharmonic maps (BM) were used to predict NOx (nitrogen oxides) emissions and relative fuel–air ratio (Fr) of a passenger city bus. For the collection of experimental data, an instrumented city bus was tested during real passenger transportation. The data were classified into four dynamic sequences: acceleration, idling, deceleration with fuel consumption, and deceleration without fuel consumption. Among them, the acceleration sequence was selected due to high NOx emissions and high fuel consumption. Experimental results were in good agreement with BM predictions. Significant parameters for predicting NOx concentration were vehicle velocity and relative fuel–air ratio (Fr). While for predicting Fr, significant parameters were the exhaust gas flow (EGF) rate, vehicle velocity, and NOx concentr...