Anghel Chiru - Academia.edu (original) (raw)

Papers by Anghel Chiru

To date, vehicle motion data logging is often done using GPS receivers. The motion parameters are... more To date, vehicle motion data logging is often done using GPS receivers. The motion parameters are useful for studies related to vehicle dynamics, road traffic and even road events reconstruction. Depending by the goal of the study, different data loggers with different parameters may be used. Commercial low cost devices can be used for collecting traffic flow data, when the sampling rate can be low (1 sample/second), but professional high speed devices are required for braking tests or crash tests. In this paper are presented some devices used for data logging in road traffic as well as in the study of the vehicle dynamics.

The study analyzes the energetic aspect of the pole vault, training in the athlete's strategy, ne... more The study analyzes the energetic aspect of the pole vault, training in the athlete's strategy, near by pole's compressing postcritical, the application of a couple of pole's bending, maintaining verticality in the negative acceleration field. The study evaluate the contribution at the elastic potential stored in the pole by application the couple and the pole's deformations in this loading states with the purpose to identify the jump. The couple's necessary intensity is evaluated from the condition that at the pole's fixing end in the box, the moment to be null. Identify the difficulty on the deformations is caused by the differentials, hard to be showed by measuring. The access to the information upon this loading's component remains in the essence the jump's kinogram, the time to maintain verticality in the negative acceleration field.

Energies

Improving the performance of internal combustion engines (ICE), together with lowering emissions,... more Improving the performance of internal combustion engines (ICE), together with lowering emissions, are the main targets for specialists in the automotive field. One option for increasing engine efficiency is creating a considerable amount of boost for the inlet combustion air by means of supercharging. In addition to common turbochargers, an alternative solution that has interested researchers for almost a century is the pressure wave supercharger (PWS). This paper is, at first, a complimentary tribute to most of the researchers that studied, experimented with and improved PW supercharging technology from the 50′s to the present. Second, this review emphasizes the performance achieved by ICEs when using PW supercharging, highlighting the limits of these main parameters in different operating conditions, based on the main reported results in the literature. It also provides an overview of PW supercharging technology, with its main advantages and disadvantages and suggests some technic...

The use of vegetable oil methyl esters has been proposed as an alternative fuel for Diesel engine... more The use of vegetable oil methyl esters has been proposed as an alternative fuel for Diesel engines. The purpose of this study is to investigate the operating conditions of a Diesel engine fuelled by mixtures of rapeseed oil and Diesel fuel. Experimental measurements and theoretical simulation of performance and emissions are presented versus classical DI Diesel Engines parameters. The paper show what are the ways that can use for improve engine emissions performances.

The basis of shape memory alloys is the martensite-austenite transformation. For this transformat... more The basis of shape memory alloys is the martensite-austenite transformation. For this transformation of the lattice structure the temperature change is one of the driving forces. In most cases electrical or thermal energy is used to activate the memory effect. In this paper, the tests and results regarding the required electrical energy to activate the memory effect will be described. If the shape memory wires work like actuators in automotive industry it is important to find the best values for the current intensity and the electrical tension. One of the questions of this investigation is to find the electrical value when the contraction and mechanical stress is constant. The defined goal is to obtain in less than one second 4-4,5% contraction at different stresses between 100-450 N/mm 2 and to analyze the electrical behavior of the samples. A great focus was given to the electrical connection to realize the activation of the actuator wires. Different parallel and serial connection...

Lately, in the field of car design, the level of noise perceived by the client has been continuou... more Lately, in the field of car design, the level of noise perceived by the client has been continuously decreased as a result of progress. An important element of this approach is the study of vibration induced by braking behavior of the coupling pad / disk brake. Based on observations made over time regarding brake noise of various combinations of pad / disk, this paper proposes a method to anticipate the possibility of producing noise when braking due to brake disc , as well as control the manufacture, to avoid possibility of its occurrence. This article does not address the mechanism which produces noise brake in the coupling pad / disk, which is fully yet unexplained by researchers. The disk is considered in two cases (made of different materials or geometric errors caused by drift in the manufacturing process), at a standard definition of the pad. A disk identified as " noisy " brake (type β) and a disk identified " silent " (type α) are compared and the influe...

Internal combustion engines have an operating efficiency that can be exploited to increase their ... more Internal combustion engines have an operating efficiency that can be exploited to increase their performance. Some of the waste gases can be recovered through technical solutions such as turbocharging. The turbocharging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. This requires an analysis of the energy balance of the internal combustion engine. This shows that there is a significant reserve of energy in the exhaust gases, which can be used to increase the engine efficiency. One solution is to use this energy to drive a turbine coupled with an electric generator. This article aims to present the result of the experimental research of the hybrid turbocharger, simulating and validating the new solutions for increasing the energy performance of internal combustion engines through hybrid turbochargers using a coupled electric generator. The simulations will be performed using AMESim software developed by Si...

The Pressure Wave technology has proved real potential in improving performance and efficiency of... more The Pressure Wave technology has proved real potential in improving performance and efficiency of thermodynamic systems. Its working principle is based on the transfer of energy between two fluids that are in direct contact for a very short period of time. This technology was implemented in many various applications, including: pressure wave superchargers for internal combustion engines, wave rotor constant volume combustors, novel generation of rotary thermal separators, wave rotor refrigerators, ultra-micro gas turbines, heat exchangers cleaning devices, etc. This paper is a theoretical analysis of the evolution of the pressures along the wave rotor channels for the exhaust gases and for the fresh air. Furthermore, a simulation of the phenomenon at the contact of the two fluids is provided in order to show the interaction of the high energy fluid with the low energy fluid. The theoretical analysis was made using COMSOL Multiphysics software. The study results were represented grap...

A major source of noise in an urban agglomeration is the road traffic. In order to analyze the ef... more A major source of noise in an urban agglomeration is the road traffic. In order to analyze the effect of the noise on the population, the local authorities need noise maps, created depending by each major noise source. Data necessary for estimate the noise generated by the road traffic are: vehicle numbers and vehicle speed, by category, and data related to the road segment: traffic flow, road surface construction and gradient. The final result – noise map – is strongly influenced by the accuracy of input data. This paper presents a method for road noise mapping, from the beginning (data acquisition) to the end (printing and evaluation of population exposure), an original approach that gives accurate results.

– The article presents the determination of the maximum number of electrovalve switchings until m... more – The article presents the determination of the maximum number of electrovalve switchings until malfunction (valve lifetime), using different contamination oil conditions (size and type of particles) in case of a test bench used for studying contaminantion behaviour of some components of the vehicle engine variable valve timing system. An analysis of the hauling time estimation in case of vehicles equiped with this type of electrohydraulic valves until this device fail due to contamination with particles from the oil was also presented in this paper. It was also created a database with tested electrovalves.

Internal combustion engines have an efficiency of operating which can be exploit to increase its ... more Internal combustion engines have an efficiency of operating which can be exploit to increase its performance. Part of the residual gases can be recovered through the technical solutions such as turbocharging. The turbocharging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. For the turbocharging process it is used a turbocharger. The turbocharger can contribute also with new technical solutions to increase the energy performance of the internal combustion engines. One of the solutions proposed for the theoretical and experimental research is the hybrid turbocharger, which has a double function, namely to compress the fresh air for the internal combustion engine, and to generate electric energy for the electric engine of the vehicle both for consumption other to be stored in batteries. This article aims is to present the result of the experimental research of the hybrid turbocharger, simulate and validate t...

SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE, 2018

The aim of the article is to present and evaluate the results of a internal combustion engine wit... more The aim of the article is to present and evaluate the results of a internal combustion engine with the Dyno-Max Software and the test bed, which has a high applicability in the field of internal combustion engines and automobiles as well as the peripheral related equipment. For research it was used a Chevy 350 engine with a 350 cubic inch (5.7-liter) small block V8 with a 4.00 and 3.48 inch bore and stroke. The base version of this engine makes 195 horsepower and features an 8.5 compression ratio.

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2013

The wire rope isolators (WRI) represent efficient solutions for vibration and shock attenuation w... more The wire rope isolators (WRI) represent efficient solutions for vibration and shock attenuation which can appear in equipment and installations exploitation. Choosing the WRI model which corresponds a certain application is the main objective for the researchers. The aim of this paper is to present the influences of the wire rope length in vibration isolation. Measurements performed with 3 different WRI models offer information on their vibration behavior depending on their length. The obtained results are useful in choosing WRI isolators for vibration attenuation applications.

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2015

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2015

The paper presents a case study regarding a the noise generated by the road traffic on a main roa... more The paper presents a case study regarding a the noise generated by the road traffic on a main road that traverse a city. Since no input data was available, all data was produced using free available sources for the base map and data collected on site for the traffic volumes and speed. The methods and tools used to process the outputs are also presented. Beside the noise mapping software, are used GPS, GIS and CAD techniques.

Applied Mechanics and Materials, 2016

TThe efficiency of the turbochargers is not satisfactory while the supercharged engine is working... more TThe efficiency of the turbochargers is not satisfactory while the supercharged engine is working at low speeds. The dual supercharging can represent a solution to improve the supercharging process efficiency of the turbochargers. Due to the different functioning principles of the turbochargers and the pressure wave superchargers, this compressors are not having the same efficiency when the engines is running at a certain speed. The pressure wave superchargers can operate with a satisfactory efficiency at low-medium engine speeds. For this reason the dual supercharging with turbocharger-pressure wave supercharger is making the supercharging processes applied on engines more efficient. The two supercharging compressors are compressing the intake air by using a part of the exhaust gases energy. Due to the pressure wave supercharger rotor is having only gas distribution role, the power needed to drive it is reduced. The driving of the rotor can be realized by the crankshaft or by an el...

Applied Mechanics and Materials, 2016

In many cases we have to estimate the speed of the vehicles involved in an accident. The aim of t... more In many cases we have to estimate the speed of the vehicles involved in an accident. The aim of this paper is to make a brief presentation of some cases solved on the question of speed and dynamics using different methods and presenting the estimated error obtained. So in the paper it will be taken into account the indication of tachograph diagram with pro and contra arguments assuming that this indication is only informative as far as the tachograph is not specially designed as an accident recorder device. In the paper it will be included the reconstruction of the accident using PC Crash facility in optimization method to reduce the error regarding the trajectory and rest position. For validation of this analysis we will provide also a video surveillance camera film high resolution versus simulation of the accident.

Proceedings of the European Automotive Congress EAEC-ESFA 2015, 2015

The goal of this study is to use different data acquisition devices based on GPS (global position... more The goal of this study is to use different data acquisition devices based on GPS (global positioning system) receivers and/or IMU (inertial measuring unit) sensors for ascertaining the vehicle’s dynamics performances. The acquisition systems used were with two GPS receivers, one GPS receiver and one inertial unit, and two GPS receivers and one inertial unit. The parameters that can be determined include velocity, longitudinal and lateral acceleration, slip angle, yaw rate, turning radius. Raw data are filtered using digital filters like CFC (Channel Frequency Class) or Kalman, and values measured with one device are used to improve the quality of data taken with another device. The tests performed involved accelerating, braking and turning. The collected data are processed using the proprietary software of the commercial acquisition systems, and also some original developed software applications.

Proceedings of the European Automotive Congress EAEC-ESFA 2015, 2015

The performances of the supercharged internal combustion engines are depending significantly on t... more The performances of the supercharged internal combustion engines are depending significantly on the efficiency of the compressors, but also on the quality of tuning of the compressors with the engines. Such an example may be the pressure wave compressor. This compressor requires a careful tuning with the engine, in order to assure a high working efficiency. More precisely, the driving speed of the compressor must be identified, for every engine speed and load domain. Researches in this direction are required, both for the pressure wave compressor separately to the engine, but also for the whole assembly mounted on the engine. Through pressure wave compressors exhaust gas and intake air is flowing. For this reason, it is necessary to evaluate the evolution in time of the two gases parameters, at different speeds of the compressor’s rotor. The measurements can be realized with special and precise equipment. Therefore, in this paper are presented such equipment, with the mounting places on the pressure wave compressor.

To date, vehicle motion data logging is often done using GPS receivers. The motion parameters are... more To date, vehicle motion data logging is often done using GPS receivers. The motion parameters are useful for studies related to vehicle dynamics, road traffic and even road events reconstruction. Depending by the goal of the study, different data loggers with different parameters may be used. Commercial low cost devices can be used for collecting traffic flow data, when the sampling rate can be low (1 sample/second), but professional high speed devices are required for braking tests or crash tests. In this paper are presented some devices used for data logging in road traffic as well as in the study of the vehicle dynamics.

The study analyzes the energetic aspect of the pole vault, training in the athlete's strategy, ne... more The study analyzes the energetic aspect of the pole vault, training in the athlete's strategy, near by pole's compressing postcritical, the application of a couple of pole's bending, maintaining verticality in the negative acceleration field. The study evaluate the contribution at the elastic potential stored in the pole by application the couple and the pole's deformations in this loading states with the purpose to identify the jump. The couple's necessary intensity is evaluated from the condition that at the pole's fixing end in the box, the moment to be null. Identify the difficulty on the deformations is caused by the differentials, hard to be showed by measuring. The access to the information upon this loading's component remains in the essence the jump's kinogram, the time to maintain verticality in the negative acceleration field.

Energies

Improving the performance of internal combustion engines (ICE), together with lowering emissions,... more Improving the performance of internal combustion engines (ICE), together with lowering emissions, are the main targets for specialists in the automotive field. One option for increasing engine efficiency is creating a considerable amount of boost for the inlet combustion air by means of supercharging. In addition to common turbochargers, an alternative solution that has interested researchers for almost a century is the pressure wave supercharger (PWS). This paper is, at first, a complimentary tribute to most of the researchers that studied, experimented with and improved PW supercharging technology from the 50′s to the present. Second, this review emphasizes the performance achieved by ICEs when using PW supercharging, highlighting the limits of these main parameters in different operating conditions, based on the main reported results in the literature. It also provides an overview of PW supercharging technology, with its main advantages and disadvantages and suggests some technic...

The use of vegetable oil methyl esters has been proposed as an alternative fuel for Diesel engine... more The use of vegetable oil methyl esters has been proposed as an alternative fuel for Diesel engines. The purpose of this study is to investigate the operating conditions of a Diesel engine fuelled by mixtures of rapeseed oil and Diesel fuel. Experimental measurements and theoretical simulation of performance and emissions are presented versus classical DI Diesel Engines parameters. The paper show what are the ways that can use for improve engine emissions performances.

The basis of shape memory alloys is the martensite-austenite transformation. For this transformat... more The basis of shape memory alloys is the martensite-austenite transformation. For this transformation of the lattice structure the temperature change is one of the driving forces. In most cases electrical or thermal energy is used to activate the memory effect. In this paper, the tests and results regarding the required electrical energy to activate the memory effect will be described. If the shape memory wires work like actuators in automotive industry it is important to find the best values for the current intensity and the electrical tension. One of the questions of this investigation is to find the electrical value when the contraction and mechanical stress is constant. The defined goal is to obtain in less than one second 4-4,5% contraction at different stresses between 100-450 N/mm 2 and to analyze the electrical behavior of the samples. A great focus was given to the electrical connection to realize the activation of the actuator wires. Different parallel and serial connection...

Lately, in the field of car design, the level of noise perceived by the client has been continuou... more Lately, in the field of car design, the level of noise perceived by the client has been continuously decreased as a result of progress. An important element of this approach is the study of vibration induced by braking behavior of the coupling pad / disk brake. Based on observations made over time regarding brake noise of various combinations of pad / disk, this paper proposes a method to anticipate the possibility of producing noise when braking due to brake disc , as well as control the manufacture, to avoid possibility of its occurrence. This article does not address the mechanism which produces noise brake in the coupling pad / disk, which is fully yet unexplained by researchers. The disk is considered in two cases (made of different materials or geometric errors caused by drift in the manufacturing process), at a standard definition of the pad. A disk identified as " noisy " brake (type β) and a disk identified " silent " (type α) are compared and the influe...

Internal combustion engines have an operating efficiency that can be exploited to increase their ... more Internal combustion engines have an operating efficiency that can be exploited to increase their performance. Some of the waste gases can be recovered through technical solutions such as turbocharging. The turbocharging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. This requires an analysis of the energy balance of the internal combustion engine. This shows that there is a significant reserve of energy in the exhaust gases, which can be used to increase the engine efficiency. One solution is to use this energy to drive a turbine coupled with an electric generator. This article aims to present the result of the experimental research of the hybrid turbocharger, simulating and validating the new solutions for increasing the energy performance of internal combustion engines through hybrid turbochargers using a coupled electric generator. The simulations will be performed using AMESim software developed by Si...

The Pressure Wave technology has proved real potential in improving performance and efficiency of... more The Pressure Wave technology has proved real potential in improving performance and efficiency of thermodynamic systems. Its working principle is based on the transfer of energy between two fluids that are in direct contact for a very short period of time. This technology was implemented in many various applications, including: pressure wave superchargers for internal combustion engines, wave rotor constant volume combustors, novel generation of rotary thermal separators, wave rotor refrigerators, ultra-micro gas turbines, heat exchangers cleaning devices, etc. This paper is a theoretical analysis of the evolution of the pressures along the wave rotor channels for the exhaust gases and for the fresh air. Furthermore, a simulation of the phenomenon at the contact of the two fluids is provided in order to show the interaction of the high energy fluid with the low energy fluid. The theoretical analysis was made using COMSOL Multiphysics software. The study results were represented grap...

A major source of noise in an urban agglomeration is the road traffic. In order to analyze the ef... more A major source of noise in an urban agglomeration is the road traffic. In order to analyze the effect of the noise on the population, the local authorities need noise maps, created depending by each major noise source. Data necessary for estimate the noise generated by the road traffic are: vehicle numbers and vehicle speed, by category, and data related to the road segment: traffic flow, road surface construction and gradient. The final result – noise map – is strongly influenced by the accuracy of input data. This paper presents a method for road noise mapping, from the beginning (data acquisition) to the end (printing and evaluation of population exposure), an original approach that gives accurate results.

– The article presents the determination of the maximum number of electrovalve switchings until m... more – The article presents the determination of the maximum number of electrovalve switchings until malfunction (valve lifetime), using different contamination oil conditions (size and type of particles) in case of a test bench used for studying contaminantion behaviour of some components of the vehicle engine variable valve timing system. An analysis of the hauling time estimation in case of vehicles equiped with this type of electrohydraulic valves until this device fail due to contamination with particles from the oil was also presented in this paper. It was also created a database with tested electrovalves.

Internal combustion engines have an efficiency of operating which can be exploit to increase its ... more Internal combustion engines have an efficiency of operating which can be exploit to increase its performance. Part of the residual gases can be recovered through the technical solutions such as turbocharging. The turbocharging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. For the turbocharging process it is used a turbocharger. The turbocharger can contribute also with new technical solutions to increase the energy performance of the internal combustion engines. One of the solutions proposed for the theoretical and experimental research is the hybrid turbocharger, which has a double function, namely to compress the fresh air for the internal combustion engine, and to generate electric energy for the electric engine of the vehicle both for consumption other to be stored in batteries. This article aims is to present the result of the experimental research of the hybrid turbocharger, simulate and validate t...

SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE, 2018

The aim of the article is to present and evaluate the results of a internal combustion engine wit... more The aim of the article is to present and evaluate the results of a internal combustion engine with the Dyno-Max Software and the test bed, which has a high applicability in the field of internal combustion engines and automobiles as well as the peripheral related equipment. For research it was used a Chevy 350 engine with a 350 cubic inch (5.7-liter) small block V8 with a 4.00 and 3.48 inch bore and stroke. The base version of this engine makes 195 horsepower and features an 8.5 compression ratio.

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2013

The wire rope isolators (WRI) represent efficient solutions for vibration and shock attenuation w... more The wire rope isolators (WRI) represent efficient solutions for vibration and shock attenuation which can appear in equipment and installations exploitation. Choosing the WRI model which corresponds a certain application is the main objective for the researchers. The aim of this paper is to present the influences of the wire rope length in vibration isolation. Measurements performed with 3 different WRI models offer information on their vibration behavior depending on their length. The obtained results are useful in choosing WRI isolators for vibration attenuation applications.

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2015

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2015

The paper presents a case study regarding a the noise generated by the road traffic on a main roa... more The paper presents a case study regarding a the noise generated by the road traffic on a main road that traverse a city. Since no input data was available, all data was produced using free available sources for the base map and data collected on site for the traffic volumes and speed. The methods and tools used to process the outputs are also presented. Beside the noise mapping software, are used GPS, GIS and CAD techniques.

Applied Mechanics and Materials, 2016

TThe efficiency of the turbochargers is not satisfactory while the supercharged engine is working... more TThe efficiency of the turbochargers is not satisfactory while the supercharged engine is working at low speeds. The dual supercharging can represent a solution to improve the supercharging process efficiency of the turbochargers. Due to the different functioning principles of the turbochargers and the pressure wave superchargers, this compressors are not having the same efficiency when the engines is running at a certain speed. The pressure wave superchargers can operate with a satisfactory efficiency at low-medium engine speeds. For this reason the dual supercharging with turbocharger-pressure wave supercharger is making the supercharging processes applied on engines more efficient. The two supercharging compressors are compressing the intake air by using a part of the exhaust gases energy. Due to the pressure wave supercharger rotor is having only gas distribution role, the power needed to drive it is reduced. The driving of the rotor can be realized by the crankshaft or by an el...

Applied Mechanics and Materials, 2016

In many cases we have to estimate the speed of the vehicles involved in an accident. The aim of t... more In many cases we have to estimate the speed of the vehicles involved in an accident. The aim of this paper is to make a brief presentation of some cases solved on the question of speed and dynamics using different methods and presenting the estimated error obtained. So in the paper it will be taken into account the indication of tachograph diagram with pro and contra arguments assuming that this indication is only informative as far as the tachograph is not specially designed as an accident recorder device. In the paper it will be included the reconstruction of the accident using PC Crash facility in optimization method to reduce the error regarding the trajectory and rest position. For validation of this analysis we will provide also a video surveillance camera film high resolution versus simulation of the accident.

Proceedings of the European Automotive Congress EAEC-ESFA 2015, 2015

The goal of this study is to use different data acquisition devices based on GPS (global position... more The goal of this study is to use different data acquisition devices based on GPS (global positioning system) receivers and/or IMU (inertial measuring unit) sensors for ascertaining the vehicle’s dynamics performances. The acquisition systems used were with two GPS receivers, one GPS receiver and one inertial unit, and two GPS receivers and one inertial unit. The parameters that can be determined include velocity, longitudinal and lateral acceleration, slip angle, yaw rate, turning radius. Raw data are filtered using digital filters like CFC (Channel Frequency Class) or Kalman, and values measured with one device are used to improve the quality of data taken with another device. The tests performed involved accelerating, braking and turning. The collected data are processed using the proprietary software of the commercial acquisition systems, and also some original developed software applications.

Proceedings of the European Automotive Congress EAEC-ESFA 2015, 2015

The performances of the supercharged internal combustion engines are depending significantly on t... more The performances of the supercharged internal combustion engines are depending significantly on the efficiency of the compressors, but also on the quality of tuning of the compressors with the engines. Such an example may be the pressure wave compressor. This compressor requires a careful tuning with the engine, in order to assure a high working efficiency. More precisely, the driving speed of the compressor must be identified, for every engine speed and load domain. Researches in this direction are required, both for the pressure wave compressor separately to the engine, but also for the whole assembly mounted on the engine. Through pressure wave compressors exhaust gas and intake air is flowing. For this reason, it is necessary to evaluate the evolution in time of the two gases parameters, at different speeds of the compressor’s rotor. The measurements can be realized with special and precise equipment. Therefore, in this paper are presented such equipment, with the mounting places on the pressure wave compressor.