Amar AYAD - Academia.edu (original) (raw)
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Papers by Amar AYAD
Engineering Failure Analysis, Jun 1, 2023
Eksploatacja i Niezawodność, Mar 31, 2023
▪ Heat flux increases with increasing contact frequency. ▪ Thermal diffusivity greatly affects co... more ▪ Heat flux increases with increasing contact frequency. ▪ Thermal diffusivity greatly affects conductive transfer. ▪ Manufacturers can use this model to assess the cylinder head's temperature field. ▪ Automotive industry can use this model to improve the heat transfer of internal combustion engine. The focus of internal combustion engine development for urban vehicles is shifting towards reducing materials by making them lighter. In order to maintain thermal and flow levels, a model was developed to study the thermal behavior of valve seats during periodic contact, which can also help improve engine performance and fuel efficiency. The model, composed of two cylindrical bars in periodic contact, takes into account the evolution and topography of the contact surface. The model's performance was evaluated through various experimental studies and showed a maximum difference of 5.05% with experimental values, in good agreement with previous literature. The results showed that heat flux increases with increasing contact frequency and thermal diffusivity affects conductive transfer. This model can be used by manufacturers to evaluate cylinder head temperature and by the automotive industry to improve heat transfer in engines.
The surface roughness between the liner and the piston rings, plays an important role for good en... more The surface roughness between the liner and the piston rings, plays an important role for good engine performance (friction, oil consumption, wear in the engine, energy losses, etc.). In this paper, an analytical model was developed to study the Tribological performance of a piston rings and rough liner taking into account different roughness orientations. A simplified model of the distribution of the hydrodynamic pressure and the load capacity in the contact are obtained from a simultaneous solution of the Reynolds equation and the equation of motion of the piston rings. A numerical model has been developed to predict the friction and the oil film thickness in mixed lubrication regime, and to evaluate the lubricant viscosity influence and the surface roughness on the engine performance. Keywords : Friction – Wear - Piston ring pack- Roughness- Hydrodynamic lubrication.
Eksploatacja i Niezawodność – Maintenance and Reliability
The focus of internal combustion engine development for urban vehicles is shifting towards reduci... more The focus of internal combustion engine development for urban vehicles is shifting towards reducing materials by making them lighter. In order to maintain thermal and flow levels, a model was developed to study the thermal behavior of valve seats during periodic contact, which can also help improve engine performance and fuel efficiency. The model, composed of two cylindrical bars in periodic contact, takes into account the evolution and topography of the contact surface. The model's performance was evaluated through various experimental studies and showed a maximum difference of 5.05% with experimental values, in good agreement with previous literature. The results showed that heat flux increases with increasing contact frequency and thermal diffusivity affects conductive transfer. This model can be used by manufacturers to evaluate cylinder head temperature and by the automotive industry to improve heat transfer in engines.
Engineering Failure Analysis
The surface roughness between the liner and the piston rings, plays an important role for good en... more The surface roughness between the liner and the piston rings, plays an important role for good engine performance (friction, oil consumption, wear in the engine, energy losses, etc.). In this paper, an analytical model was developed to study the Tribological performance of a piston rings and rough liner taking into account different roughness orientations. A simplified model of the distribution of the hydrodynamic pressure and the load capacity in the contact are obtained from a simultaneous solution of the Reynolds equation and the equation of motion of the piston rings. A numerical model has been developed to predict the friction and the oil film thickness in mixed lubrication regime, and to evaluate the lubricant viscosity influence and the surface roughness on the engine performance. Keywords : Friction – Wear - Piston ring pack- Roughness- Hydrodynamic lubrication.
Engineering Failure Analysis, Jun 1, 2023
Eksploatacja i Niezawodność, Mar 31, 2023
▪ Heat flux increases with increasing contact frequency. ▪ Thermal diffusivity greatly affects co... more ▪ Heat flux increases with increasing contact frequency. ▪ Thermal diffusivity greatly affects conductive transfer. ▪ Manufacturers can use this model to assess the cylinder head's temperature field. ▪ Automotive industry can use this model to improve the heat transfer of internal combustion engine. The focus of internal combustion engine development for urban vehicles is shifting towards reducing materials by making them lighter. In order to maintain thermal and flow levels, a model was developed to study the thermal behavior of valve seats during periodic contact, which can also help improve engine performance and fuel efficiency. The model, composed of two cylindrical bars in periodic contact, takes into account the evolution and topography of the contact surface. The model's performance was evaluated through various experimental studies and showed a maximum difference of 5.05% with experimental values, in good agreement with previous literature. The results showed that heat flux increases with increasing contact frequency and thermal diffusivity affects conductive transfer. This model can be used by manufacturers to evaluate cylinder head temperature and by the automotive industry to improve heat transfer in engines.
The surface roughness between the liner and the piston rings, plays an important role for good en... more The surface roughness between the liner and the piston rings, plays an important role for good engine performance (friction, oil consumption, wear in the engine, energy losses, etc.). In this paper, an analytical model was developed to study the Tribological performance of a piston rings and rough liner taking into account different roughness orientations. A simplified model of the distribution of the hydrodynamic pressure and the load capacity in the contact are obtained from a simultaneous solution of the Reynolds equation and the equation of motion of the piston rings. A numerical model has been developed to predict the friction and the oil film thickness in mixed lubrication regime, and to evaluate the lubricant viscosity influence and the surface roughness on the engine performance. Keywords : Friction – Wear - Piston ring pack- Roughness- Hydrodynamic lubrication.
Eksploatacja i Niezawodność – Maintenance and Reliability
The focus of internal combustion engine development for urban vehicles is shifting towards reduci... more The focus of internal combustion engine development for urban vehicles is shifting towards reducing materials by making them lighter. In order to maintain thermal and flow levels, a model was developed to study the thermal behavior of valve seats during periodic contact, which can also help improve engine performance and fuel efficiency. The model, composed of two cylindrical bars in periodic contact, takes into account the evolution and topography of the contact surface. The model's performance was evaluated through various experimental studies and showed a maximum difference of 5.05% with experimental values, in good agreement with previous literature. The results showed that heat flux increases with increasing contact frequency and thermal diffusivity affects conductive transfer. This model can be used by manufacturers to evaluate cylinder head temperature and by the automotive industry to improve heat transfer in engines.
Engineering Failure Analysis
The surface roughness between the liner and the piston rings, plays an important role for good en... more The surface roughness between the liner and the piston rings, plays an important role for good engine performance (friction, oil consumption, wear in the engine, energy losses, etc.). In this paper, an analytical model was developed to study the Tribological performance of a piston rings and rough liner taking into account different roughness orientations. A simplified model of the distribution of the hydrodynamic pressure and the load capacity in the contact are obtained from a simultaneous solution of the Reynolds equation and the equation of motion of the piston rings. A numerical model has been developed to predict the friction and the oil film thickness in mixed lubrication regime, and to evaluate the lubricant viscosity influence and the surface roughness on the engine performance. Keywords : Friction – Wear - Piston ring pack- Roughness- Hydrodynamic lubrication.