Abdallah Bouabidi

A computational and an experimental study on the effect of the chimney height on the thermal characteristics of a solar chimney power plant

The aim of this paper is to highlight the impact of the chimney height on the local characteristics of the air flow within a solar chimney power plant. The solar chimney power plant prototype was numerically and experimentally investigated. The experimental prototype of the solar chimney power plant was built in the National School of Engineers of Sfax, University of Sfax, Tunisia in the North Africa. The prototype is characterized by a collector diameter equal to D = 2750 mm, a collector height equal to h = 50 mm, a chimney height equal to H = 3000 mm, and a chimney diameter equal to d = 160 mm. The air flow has been simulated using the commercial software Ansys Fluent 17.0 and the computational findings have been validated using our experimental results. Computational fluid dynamics findings confirm that the chimney height is very influential on the local characteristics of the solar chimney power plant.

Study of Hydrostatic Pump Created Under Liquid Sloshing in a Rectangular Tank Subjected to External Excitation

The aim of this work is to study the hydrostatic pump created under liquid sloshing in a rectangular tank partially filled with liquid. A numerical simulation was performed to predict the liquid motion in the tank. The apparition of the compression and the depression zones due to the liquid motion was presented and analyzed. An experimental setup with sinusoidal movement was developed to study the hydrostatic pump. The hydrostatic pump is created using a mixing element. The experimental results show that the compression and the depression zones can create the hydrostatic pump. The effect of the connecting chamber value was studied for different values of external excitation frequency. The pump depends considerably on the dimension of the connecting zone between the two volumes. For the different connecting chamber values, the pumped quantity increase with the increase of the frequency.

Cycling Performances and Failure Modes for AGM and Standard Flooded Lead Acid Batteries under Partial State of Charge Mode

AbstractIn this work, the failure mode of the lead acid battery under 17.5% depth of discharge was predicted. Both the developed lead acid absorbent glass ma (AGM) battery for microhybrid applications and the standard flooded battery were tested. The end of discharge voltage and the charging factor were presented for each type of battery. The analysis of the negative plates after cycling was carried out for the two types of batteries. The test results revealed that they significantly depend on the battery technology. The standard flooded battery fails from the second unit of the test, whereas the AGM performs 16 units. For the standard flooded, a stratification of lead sulfate is observed and causes the end of the battery life. However, the sulfate is homogeneous according to the plate’s area for the AGM battery.

Effect of the number of turbine blades on the air flow within a solar chimney power plant

Solar chimney power plants generate thermal heat and electrical power using the radiation from sun. These systems are characterized by their high costs. In fact, it is required to optimize the components of the solar system such as the collector, the chimney, the absorber, and the turbine. This paper focuses on the effect of the number of turbine blades on the air flow within a small prototype of a solar chimney power plant. Four configurations with different turbine blades are proposed to study the effect of the turbine blades number on the thermal characteristics of a solar chimney power plant. For each configuration, the distribution of the magnitude velocity, the air temperature, the pressure, the turbulent kinetic energy, and the turbulent viscosity are presented and discussed. This paper is identified to be of interest for engineers and designers for increasing the power output of a solar chimney power plant.

Study of the Collector Diameter Effect on the Characteristics of the Solar Chimney Power Plant

This chapter aimed to optimize the geometry of the collector in a solar chimney power plant (SCPP). Particularly, we were interested in the study of the collector diameter effect on the SCPP output. A two-dimensional steady model with the standard k-e turbulence model has been developed using the commercial computational fluid dynamics (CFD) code “ANSYS Fluent 17.0.” A numerical simulation was achieved to study the local characteristics of the air flow inside the SCPP. Four collector diameters, equal to D = 100 cm, D = 200 cm, D = 300 cm, and D = 400 cm, were considered in this study. The local flow characteristics were presented and discussed for each case. The comparison shows that the collector diameter is an important parameter for the optimization of the solar setup.

Computer Simulation of Liquid Motion in a Container Subjected to Sinusoidal Excitation with Different Turbulence Models

The sloshing phenomena occur when a partially filled container is subjected to external excitation. The aim of the present chapter is to perform a numerical simulation of the liquid sloshing using the “Fluent” software. The simulation of the two-phase application was achieved using the volume of fluid (VOF). The container was subjected to sinusoidal excitation. To impose the external excitation, an user-defined function was developed and interpreted in “Fluent”. Four numerical simulations were developed with different turbulence models: standard k–e, RNG k–e, Realizable k–e, and standard k–e. The fluid flow characteristics were presented and discussed for the different simulation cases. The numerical results are compared with the experimental data. The comparison between the numerical and the experimental results shows a good agreement for the turbulence model standard k–e.

Study of the Turbulence Model Effect on the Airflow Characteristics Inside a Solar Chimney Power Plant

A numerical simulation was developed to study the behavior of the airflow characteristics inside the solar chimney power plant (SCPP). A two-dimensional (2D) steady model has been carried out using the commercial computational fluid dynamics (CFD) code ANSYS Fluent 17.0. In this chapter, five turbulence models were tested to present the airflow characteristics distribution such as the magnitude velocity, temperature, pressure, and turbulence characteristics. The above work showed that the turbulence model types have a direct effect on the numerical results. Computational results were compared to the experimental data found by Kasaeian et al. (2014) to choose the adequate model.