HAL (Le Centre pour la Communication Scientifique Directe), May 1, 2019
This paper proposes a numerical approach for the accurate estimation of convective heat transfer ... more This paper proposes a numerical approach for the accurate estimation of convective heat transfer coefficients in the end region of an Integrated Starter Generator (ISG) used into a mild-hybrid vehicle. A simplified numerical model based on CFD methods is developed to provide a qualitative understanding the mechanism of convective heat transfer over a large operation range. The effect of the rotation speed on the variation of the convective heat transfer coefficients inside the end region is thoroughly investigated. Heat flux paths are also identified for the entire operation range. CFD calculation results are used to provide an enhancement to the Schubert's correlation for the different surfaces delimiting the end region of the ISG. Subsequently, general correlations are defined using averaged Nusselt numbers as a function of Reynolds numbers. Then, a detailed lumped thermal network is developed which estimates correctly the temperature distribution in different areas of the electrical machine. The obtained numerical data are validated using local temperature measurements.
The population of many cities in the world is increasing over time, which leads to urban sprawl a... more The population of many cities in the world is increasing over time, which leads to urban sprawl and an increase in energy consumption and polluting gases, especially in urban areas. Indeed, energy consumption and pollutant gases threaten human life. On the other hand, technology has affected every aspect of our life. To prevent such threats, cities must be smart so that they can be managed in a smart way. In this sense, the main objective of this paper is to realize a prototype of an Internet of Things (IoT) system to save human life while preserving the environment. This system is called I-CITY and incorporates Smart Parking, Intelligent fire detection system with automatic fire extinguisher and quality monitoring system around the city environment. This invented device is made up of web access that gathers, sends, and processes data from their environment using embedded systems including processors, sensors, and communication gear. Finally, I-CITY solves parking problems in cities with high populations. It also contains a flame detection system that can identify local fires by processing signals receives from flames. However, this system contains a fire extinguisher to automatically extinguish the fire. Finally, an air quality monitoring system collects information from their surroundings. The information from this work could be used by decision market for better city planning.
This paper investigates numerically and experimentally the flow structure and convective heat tra... more This paper investigates numerically and experimentally the flow structure and convective heat transfers in an unconfined air gap of a discoid technology rotor–stator system. The cavity between the interdisk is defined by dimensionless spacing varying between G = 0.02 (Haidar et al., 2020, “Numerical and Experimental Study of Flow and Convective Heat Transfer on a Rotor of a Discoidal Machine With Eccentric Impinging Jet,” J. Therm. Sci. Eng. Appl., 12(2), 021012) and G = 0.16. For experimental data, an infrared thermography is applied to obtain a measurement of the rotor surface temperatures and a steady-state energy equation is solved to evaluate the local convective coefficients. A numerical study is performed with a computational code ansys-fluent and based to apply two different turbulence models named the Reynolds stress model (RSM) and k–ε renormalization group (RNG). The results of the numerical simulation are compared with experimental results on heat transfer for the rotati...
International Journal of Renewable Energy Research, 2019
This work presents a numerical and experimental study of convection heat transfer in the unconfin... more This work presents a numerical and experimental study of convection heat transfer in the unconfined air gap of a discoidal technology rotor-stator system. In particular, the rotor is cooled here by an eccentric air jet impingement. The cavity is characterized by a dimensionless spacing G = 0.02 and a low aspect ratio for the jet H/D= 0.25. the rotational Reynolds numbers from 2.38*10^5 to 5.44*10^5 and the jet Reynolds number between 16.5*10^3 and 49.5*10^3 are used. The experimental technique is based on using infrared thermography to access the rotor surface temperature measurement, and on the numerical resolution of the energy equation at steady state to evaluate the local convective coefficient. The numerical study is based on the turbulence model RSM (Reynolds Stress Model). The results of this study are described in terms of radial distributions of the mean velocity components, Reynolds stress tensor components and corresponding local and mean Nusselt numbers. Three flow regio...
Journal of Thermal Science and Engineering Applications
This work focuses on the numerical and experimental study of convective heat transfer in a rotor ... more This work focuses on the numerical and experimental study of convective heat transfer in a rotor of a discoidal the machine with an eccentric impinging jet. Convective heat transfers are determined experimentally in steady state on the surface of a single rotating disk. The experimental technique is based on the use of infrared thermography to access surface temperature measurement, and on the numerical resolution of the energy equation in steady-state, to evaluate local convective coefficients. The results from the numerical simulation are compared with heat transfer experiments for rotational Reynolds numbers between 2.38×105 and 5.44×105 and for the jet's Reynolds numbers ranging from 16.5×103 to 49.6 ×103. A good agreement between the two approaches was obtained in the case of a single rotating disk, which confirms us in the choice of our numerical model. On the other hand, a numerical study of the flow and convective heat transfer in the case of an unconfined rotor-stator s...
HAL (Le Centre pour la Communication Scientifique Directe), May 1, 2019
This paper proposes a numerical approach for the accurate estimation of convective heat transfer ... more This paper proposes a numerical approach for the accurate estimation of convective heat transfer coefficients in the end region of an Integrated Starter Generator (ISG) used into a mild-hybrid vehicle. A simplified numerical model based on CFD methods is developed to provide a qualitative understanding the mechanism of convective heat transfer over a large operation range. The effect of the rotation speed on the variation of the convective heat transfer coefficients inside the end region is thoroughly investigated. Heat flux paths are also identified for the entire operation range. CFD calculation results are used to provide an enhancement to the Schubert's correlation for the different surfaces delimiting the end region of the ISG. Subsequently, general correlations are defined using averaged Nusselt numbers as a function of Reynolds numbers. Then, a detailed lumped thermal network is developed which estimates correctly the temperature distribution in different areas of the electrical machine. The obtained numerical data are validated using local temperature measurements.
The population of many cities in the world is increasing over time, which leads to urban sprawl a... more The population of many cities in the world is increasing over time, which leads to urban sprawl and an increase in energy consumption and polluting gases, especially in urban areas. Indeed, energy consumption and pollutant gases threaten human life. On the other hand, technology has affected every aspect of our life. To prevent such threats, cities must be smart so that they can be managed in a smart way. In this sense, the main objective of this paper is to realize a prototype of an Internet of Things (IoT) system to save human life while preserving the environment. This system is called I-CITY and incorporates Smart Parking, Intelligent fire detection system with automatic fire extinguisher and quality monitoring system around the city environment. This invented device is made up of web access that gathers, sends, and processes data from their environment using embedded systems including processors, sensors, and communication gear. Finally, I-CITY solves parking problems in cities with high populations. It also contains a flame detection system that can identify local fires by processing signals receives from flames. However, this system contains a fire extinguisher to automatically extinguish the fire. Finally, an air quality monitoring system collects information from their surroundings. The information from this work could be used by decision market for better city planning.
This paper investigates numerically and experimentally the flow structure and convective heat tra... more This paper investigates numerically and experimentally the flow structure and convective heat transfers in an unconfined air gap of a discoid technology rotor–stator system. The cavity between the interdisk is defined by dimensionless spacing varying between G = 0.02 (Haidar et al., 2020, “Numerical and Experimental Study of Flow and Convective Heat Transfer on a Rotor of a Discoidal Machine With Eccentric Impinging Jet,” J. Therm. Sci. Eng. Appl., 12(2), 021012) and G = 0.16. For experimental data, an infrared thermography is applied to obtain a measurement of the rotor surface temperatures and a steady-state energy equation is solved to evaluate the local convective coefficients. A numerical study is performed with a computational code ansys-fluent and based to apply two different turbulence models named the Reynolds stress model (RSM) and k–ε renormalization group (RNG). The results of the numerical simulation are compared with experimental results on heat transfer for the rotati...
International Journal of Renewable Energy Research, 2019
This work presents a numerical and experimental study of convection heat transfer in the unconfin... more This work presents a numerical and experimental study of convection heat transfer in the unconfined air gap of a discoidal technology rotor-stator system. In particular, the rotor is cooled here by an eccentric air jet impingement. The cavity is characterized by a dimensionless spacing G = 0.02 and a low aspect ratio for the jet H/D= 0.25. the rotational Reynolds numbers from 2.38*10^5 to 5.44*10^5 and the jet Reynolds number between 16.5*10^3 and 49.5*10^3 are used. The experimental technique is based on using infrared thermography to access the rotor surface temperature measurement, and on the numerical resolution of the energy equation at steady state to evaluate the local convective coefficient. The numerical study is based on the turbulence model RSM (Reynolds Stress Model). The results of this study are described in terms of radial distributions of the mean velocity components, Reynolds stress tensor components and corresponding local and mean Nusselt numbers. Three flow regio...
Journal of Thermal Science and Engineering Applications
This work focuses on the numerical and experimental study of convective heat transfer in a rotor ... more This work focuses on the numerical and experimental study of convective heat transfer in a rotor of a discoidal the machine with an eccentric impinging jet. Convective heat transfers are determined experimentally in steady state on the surface of a single rotating disk. The experimental technique is based on the use of infrared thermography to access surface temperature measurement, and on the numerical resolution of the energy equation in steady-state, to evaluate local convective coefficients. The results from the numerical simulation are compared with heat transfer experiments for rotational Reynolds numbers between 2.38×105 and 5.44×105 and for the jet's Reynolds numbers ranging from 16.5×103 to 49.6 ×103. A good agreement between the two approaches was obtained in the case of a single rotating disk, which confirms us in the choice of our numerical model. On the other hand, a numerical study of the flow and convective heat transfer in the case of an unconfined rotor-stator s...
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Papers by chadia haidar