Dr. Ramy Shaltout is an Assistant Professor in the faculty of Engineering, Zagazig University, Egypt. Dr.Shaltout graduated in 2006 at the Mechanical Engineering Dept. Zagazig University. In 2010 He had his Master degree in Mechanical and Material Engineering-Polytechnic University Valencia- Spain. In 2012 Dr. Shaltout awarded an internship with the railway dynamic group in lead by Prof. Stefano Bruni in Politecnico di Milano-Italy. He had the PhD title on March 2013. In the period from 2014 to 2016 was working as a research associate (RA) in NewRail center for railway research- Newcastle University-UK. In the period from 2006 to 2008 Dr. Shaltout worked as a teaching assistant in the faculty of mechanical engineering- Zagazig University-Egypt.
The direct flow evacuated tube collector (ETC) is a highly efficient solar energy collector. It h... more The direct flow evacuated tube collector (ETC) is a highly efficient solar energy collector. It has the advantage of using forced convection, which increases its efficiency compared to other ETC systems. In the present study, a helical tube ETC is proposed and compared to the traditional U-tube ETC. The helical tube was designed with three, seven, and eleven helical steps over the 1.8 m length of the ETC and was tested at flow rates of 10, 20, and 30 l/h. The helical tube ETC achieved energy and exergy efficiency enhancements over the traditional U-tube ETC of 6.1%, and 3.8%, respectively, at the 10 l/h flow rate using the eleven-step helical tube ETC. However, the maximum average energy and exergy efficiencies of 38.6% and 18%, respectively, were achieved in the seven-step helical tube ETC at the highest flow rate of 30 l/h. The cost analysis revealed that using the three-step helical tube instead of a traditional U-tube will produce hot water with a cost of 0.012 $/kWh at the 10 l/h flow rate, while the maximum cost will reach 0.15 $/kWh for the eleven-step helical tube using the 30 l/h flow rate.
This article aims to investigate the aerodynamic noise of the pantograph of the high-speed trains... more This article aims to investigate the aerodynamic noise of the pantograph of the high-speed trains in different operating conditions. CFD technique was used to assess the acoustic noise of the pantograph components. Three-dimensional computational simulations were performed using FLUENT software. Comprehensive analyses of the acoustic pressure and the air velocity distributions were accomplished for the detailed full-scale pantograph components. Good agreement was found between the obtained results and the reported results in the literature. Vortex shedding was the main source of noise at the pantograph panhead and knee. A modified model for the pantograph was introduced to reduce the aerodynamic noise of the pantograph’s panhead. A different design profile for the collector was presented as a possible solution for the reduction of both the aerodynamic noise and the reduction of the fluctuating forces at the panhead-catenary interaction, which affects the quality of the power transmi...
The importance of modelling and simulation has recently increased in the field of railway systems... more The importance of modelling and simulation has recently increased in the field of railway systems. The necessity for design, analysis and performance evaluation of the railway systems requires the use of advanced computational techniques that use fully nonlinear formulations which permit accurate modelling through capturing significant details of these systems. The paper presents a comprehensive computational approach employed in flexible simulation tool for the dynamic analysis of vehicle–track interaction based on multibody formulations. The novel numerical approach in the presented paper enables the study of different configurations of railway vehicles and various track combinations. The presented simulation tool was verified for the analysis of the Manchester Benchmark, and the results were compared with those obtained using different commercial simulation packages. The main objective of the comparison was to test and validate the implemented computational approach and the developed simulation tool to check its reliability and flexibility in the dynamic analysis of different railway systems.
In the present paper, the formation and development of cavitation inside the nozzle of an atomize... more In the present paper, the formation and development of cavitation inside the nozzle of an atomizer with different geometrical characteristics have been studied numerically. Different shapes of inlet nozzles and different nozzle-length-to-diameter ratios have been investigated. The developed model has been built as a three-dimensional (3D) one, where the turbulence is modeled considering large eddy simulation. The obtained computational results showed good agreement with the reported experimental results. It has been found that the occurrence of cavitation depends on the amount of energy needed to overcome the viscosity and friction between the liquid layers. The mass flowing through the nozzle decreases with increasing cavitation. The intensity of cavitation depends on the nozzle entrance shape. Sharp edges cause cavitation to occur early in the nozzle, followed by an inclined shape, and then the curved entrance. The dissipative energy in the cavitation and bubble collapse result in...
The direct flow evacuated tube collector (ETC) is a highly efficient solar energy collector. It h... more The direct flow evacuated tube collector (ETC) is a highly efficient solar energy collector. It has the advantage of using forced convection, which increases its efficiency compared to other ETC systems. In the present study, a helical tube ETC is proposed and compared to the traditional U-tube ETC. The helical tube was designed with three, seven, and eleven helical steps over the 1.8 m length of the ETC and was tested at flow rates of 10, 20, and 30 l/h. The helical tube ETC achieved energy and exergy efficiency enhancements over the traditional U-tube ETC of 6.1%, and 3.8%, respectively, at the 10 l/h flow rate using the eleven-step helical tube ETC. However, the maximum average energy and exergy efficiencies of 38.6% and 18%, respectively, were achieved in the seven-step helical tube ETC at the highest flow rate of 30 l/h. The cost analysis revealed that using the three-step helical tube instead of a traditional U-tube will produce hot water with a cost of 0.012 $/kWh at the 10 l/h flow rate, while the maximum cost will reach 0.15 $/kWh for the eleven-step helical tube using the 30 l/h flow rate.
This article aims to investigate the aerodynamic noise of the pantograph of the high-speed trains... more This article aims to investigate the aerodynamic noise of the pantograph of the high-speed trains in different operating conditions. CFD technique was used to assess the acoustic noise of the pantograph components. Three-dimensional computational simulations were performed using FLUENT software. Comprehensive analyses of the acoustic pressure and the air velocity distributions were accomplished for the detailed full-scale pantograph components. Good agreement was found between the obtained results and the reported results in the literature. Vortex shedding was the main source of noise at the pantograph panhead and knee. A modified model for the pantograph was introduced to reduce the aerodynamic noise of the pantograph’s panhead. A different design profile for the collector was presented as a possible solution for the reduction of both the aerodynamic noise and the reduction of the fluctuating forces at the panhead-catenary interaction, which affects the quality of the power transmi...
The importance of modelling and simulation has recently increased in the field of railway systems... more The importance of modelling and simulation has recently increased in the field of railway systems. The necessity for design, analysis and performance evaluation of the railway systems requires the use of advanced computational techniques that use fully nonlinear formulations which permit accurate modelling through capturing significant details of these systems. The paper presents a comprehensive computational approach employed in flexible simulation tool for the dynamic analysis of vehicle–track interaction based on multibody formulations. The novel numerical approach in the presented paper enables the study of different configurations of railway vehicles and various track combinations. The presented simulation tool was verified for the analysis of the Manchester Benchmark, and the results were compared with those obtained using different commercial simulation packages. The main objective of the comparison was to test and validate the implemented computational approach and the developed simulation tool to check its reliability and flexibility in the dynamic analysis of different railway systems.
In the present paper, the formation and development of cavitation inside the nozzle of an atomize... more In the present paper, the formation and development of cavitation inside the nozzle of an atomizer with different geometrical characteristics have been studied numerically. Different shapes of inlet nozzles and different nozzle-length-to-diameter ratios have been investigated. The developed model has been built as a three-dimensional (3D) one, where the turbulence is modeled considering large eddy simulation. The obtained computational results showed good agreement with the reported experimental results. It has been found that the occurrence of cavitation depends on the amount of energy needed to overcome the viscosity and friction between the liquid layers. The mass flowing through the nozzle decreases with increasing cavitation. The intensity of cavitation depends on the nozzle entrance shape. Sharp edges cause cavitation to occur early in the nozzle, followed by an inclined shape, and then the curved entrance. The dissipative energy in the cavitation and bubble collapse result in...
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