scholarly journals CFD Analysis of Hybrid Solar Chimney Power Plant

2018 ◽  
Vol 225 ◽  
pp. 04011
Author(s):  
Mohammed A. Aurybi ◽  
Hussain H. Al-Kayiem ◽  
Syed I.U. Gilani ◽  
Ali A. Ismaeel
Keyword(s):  
Flue Gas ◽  
Navier Stokes ◽  
Discrete Ordinates ◽  
Hybrid Mode ◽  
Solar Chimney ◽  
Ansys Fluent ◽  
Novel Approach ◽  
Fluent Software ◽  
Solar Chimney Power Plant ◽  
Energy Equations

In this study, a novel approach has been proposed as a solar chimney integrated with an external heat source to extend the system operation during the absence of solar energy. Flue gas channels have been utilized to exchange heat with the air inside the collector of the solar chimney. The hybrid solar chimney has been investigated numerically by ANSYS-Fluent software, using discrete ordinates radiation model. The hybrid system was simulated in 3D, steady-state by solving Navier-Stokes and energy equations. The numerical results have been validated using experimental measurements of a conventional solar chimney. The influence of flue channels on the system performance was predicted and analyzed in hybrid mode. With 0.002 kg/s of flue gas at 100°C injected in flue channels during the daytime; hybrid mode results demonstrated enhancement of 24% and 9 % for velocity and temperature, respectively. The power generation was enhanced by 56%. It has been proved that the proposed technique is able to resolve the set back of night operation problem of the solar chimney plants.

scholarly journals Experimental and Numerical Study of Collector Geometry Effect on Solar Chimney Performance

2017 ◽  
Vol 12 (4) ◽  
pp. 59-71
Author(s):  
Aseel K. Shyaa ◽  
Rafea A. H. Albaldawi ◽  
Maryam Muayad Abbood
Keyword(s):  
Power Plant ◽  
Numerical Study ◽  
Governing Equations ◽  
Solar Chimney ◽  
Ansys Fluent ◽  
Glass Cover ◽  
Pilot Work ◽  
Fluent Software ◽  
Design Velocity ◽  
Solar Chimney Power Plant

There have been many advances in the solar chimney power plant  since 1930 and the first pilot work was built in Spain (Manzanares) that produced 50 KW. The solar chimney power plant is considered of a clean power generation that needs to be investigated  to enhance the performance by studying the effect of changing the area of passage of air to enhance the velocity towards the chimney to maximize design velocity. In this experimental and numerical study, the reduction area of solar collector was investigated. The reduction area that mean changing the height of glass cover from the absorbing plate (h1=3.8cm, h2=2.6cm and h3=1.28cm). The numerical study was performed using ANSYS Fluent software package (version 14.0) to solve governing equations. The aim of this work was to study the effect of change the height of reduction area to the design velocity (velocity move the blade of turbine at inlet in the chimney). The results showed that the third height (h3=1.28cm) gives the best result because when decreasing the height between the glass cover and absorbing plate, the area between them decreased and the design velocity increased then the efficiency of solar chimney model was increased.

Performance Analysis of the Small-Scale α-Type Stirling Engine Using Computational Fluid Dynamics Tools

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Zbigniew Buliński ◽  
Ireneusz Szczygieł ◽  
Adam Kabaj ◽  
Tomasz Krysiński ◽  
Paweł Gładysz ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Stirling Engine ◽  
Coefficient Of Performance ◽  
Navier Stokes ◽  
Small Scale ◽  
Ansys Fluent ◽  
Fluent Software ◽  
Energy Equations

This paper presents the computational fluid dynamics (CFD) model of small-scale α-type Stirling engine. The developed mathematical model comprises of unsteady Reynolds averaged Navier–Stokes set of equations, i.e., continuity, momentum, and energy equations; turbulence was modeled using standard κ–ω model. Moreover, presented numerical model covers all modes of heat transfer inside the engine: conduction, convection, and radiation. The model was built in the framework of the commercial CFD software ANSYS fluent. Piston movements were modeled using dynamic mesh capability in ANSYS fluent; their movement kinematics was described based on the crankshaft geometry and it was implemented in the model using user-defined functions written in C programming language and compiled with a core of the ANSYS fluent software. The developed numerical model was used to assess the performance of the analyzed Stirling engine. For this purpose, different performance measures were defined, including coefficient of performance (COP), exergy efficiency, and irreversibility factor. The proposed measures were applied to evaluate the influence of different heating strategies of the small-scale α-type Stirling engine.

Comparative Energetic and Exergetic Analysis of Conventional and Sloped Solar Chimney Power Plants

2020 ◽  
Vol 9 (4) ◽  
pp. 57-73
Author(s):  
Hela Atia ◽  
Adrian Ilinca ◽  
Ali Snoussi ◽  
Rachid Boukchina ◽  
Ammar Ben Brahim
Keyword(s):  
Inclination Angle ◽  
Power Plants ◽  
Energetic Efficiency ◽  
Cfd Analysis ◽  
Exergy Destruction ◽  
Solar Chimney ◽  
Ansys Fluent ◽  
Solar Radiation Intensity ◽  
Fluent Software ◽  
Exergetic Analysis

A CFD analysis using ANSYS Fluent software was conducted to study the effects of collector slope on solar chimney's performances. Three solar chimney configurations, named A, B, and C, which correspond, respectively, to an inclination angle of the collector roof of 0°, 2.5°, and 5°, were investigated. The results show that the thermodynamic performances of the solar chimney were improved by increasing the inclination angle of the collector roof. In fact, the power extracted from the sloped solar chimney power plants increases with increasing the inclination angle and the solar radiation intensity, while it achieves a maximum at 800 W/m2 for configuration A. The energetic and the exergetic analysis show that configure B has the best performance in terms of conventional, effective, and total efficiencies of the collector and in terms of exergy destruction ratios in both the collector and the transition section. Whereas, configuration C has the highest amount of power extracted and the best overall energetic efficiency.

Effect of Surface Radiation on Free Convection in Vertical Cylinders Partially Annular

2018 ◽  
Vol 389 ◽  
pp. 36-49
Author(s):  
Belkacem Ould Said ◽  
Mohamed Amine Medebber ◽  
Nourddine Retiel
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Radiation Heat Transfer ◽  
Surface Radiation ◽  
Navier Stokes ◽  
Discrete Ordinates ◽  
Energy Equations ◽  
Vertical Cylinders ◽  
Rayleigh Numbers ◽  
Emissivity Coefficient

The coupled of free convection with surface radiation in an annular region of two concentric vertical cylinders filled with air has been numerically investigated. The steady-state continuity, Navier–Stokes and energy equations were carried out by the finite volume method, and the Discrete Ordinates Method (DOM) was used to solve the radiative heat transfer equation (RTE). The computations have been performed for 103 ≤Ra≤ 106, with the emissivity coefficient of all the walls varying between 0 and 1. The influence of the both, Rayleigh numbers and emissivity coefficient of the wall for fixed height ratio X=0.5 on natural convection and radiation heat transfer in enclosure have been solved. The result shows that surface radiation significantly altered the temperature distribution and the flow patterns, especially at higher Rayleigh numbers. The average Nusselt number has also been discussed for different emissivity through the enclosure.

scholarly journals A comparative study of URANS, DDES and DES simulations of Jetstream 31 aircraft near the compressibility limit

2021 ◽  
Vol 16 (2) ◽  
pp. 159-172
Author(s):  
Hrishabh Chaudhary ◽  
Nicolas Ledos ◽  
László Könözsy
Keyword(s):  
Comparative Study ◽  
Turbulence Modeling ◽  
Pressure Coefficient ◽  
Turbulence Models ◽  
Flight Test ◽  
Scale Model ◽  
Navier Stokes ◽  
Ansys Fluent ◽  
Fluent Software ◽  
Lift And Drag

This work presents a comparative study of Unsteady Reynolds–Averaged Navier–Stokes (URANS), Detached Eddy Simulations (DES) and Delayed Detached Eddy Simulations (DDES) turbulence modeling approaches by performing numerical investigation with the ANSYS-FLUENT software package on a full-scale model of the Jetstream 31 aircraft. The lift and drag coefficients obtained from different models are compared with flight test data, wind tunnel data and theoretical estimates. The different turbulence models are also compared with each other on the basis of pressure coefficient distributions and velocity fluctuations along various lines and sections of the aircraft. For the mesh and the conditions presented in this study, the DDES Spalart–Allmaras model gives the best overall results.

Numerical Study of Combined Surface Radiation and Natural Convection in Vertical Conical Annular Enclosure

2021 ◽  
Vol 408 ◽  
pp. 19-32
Author(s):  
Mohamed Amine Medebber ◽  
Belkacem Ould Said ◽  
Noureddine Retiel
Keyword(s):  
Rayleigh Number ◽  
Numerical Study ◽  
Cone Angle ◽  
Outer Radius ◽  
Surface Radiation ◽  
Navier Stokes ◽  
Discrete Ordinates ◽  
Surface Emissivity ◽  
Radiation Exchange ◽  
Energy Equations

The present study investigates the combined free convection and surface radiation in a conical annular cylinder filled with air (Pr=0.71). The steady-state continuity, Navier–Stokes and energy equations were carried out by the finite volume method, and the Discrete Ordinates Method (DOM) was used to solve the radiative heat transfer equation (RTE). The boundary conditions are such that the inner and the outer radius of cone are maintained at hot (Th) and cold (Tc) isothermal temperature. The horizontal upper and lower walls are assumed to be isolated. Concerning the radiation exchange, we consider that the fluid (air) is transparent, so only the solid surfaces contribute to the radiation exchange and assumed to be diffuse-gray. The computations are performed for Rayleigh number (Ra) in the range 103≤Ra≤106 , the surface emissivity (ε) 0≤ε≤1 and the cone angle () 63o, 76o, 80o and 84o. The key parameters for this analysis are considered as Rayleigh number (Ra), surface emissivity (ε) and the cone angle (). Results are presented in terms of isotherms, streamlines and the average Nusselt numbers.

scholarly journals Simulation and Experimental Study of the Influence of the Baffles on Solar Chimney Power Plant System

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 902
Author(s):  
Haixia Wang ◽  
Jusheng Chen ◽  
Ping Dai ◽  
Fujiang Zhang ◽  
Qingling Li
Keyword(s):  
Power Plant ◽  
3D Models ◽  
Temperature Fields ◽  
Solar Chimney ◽  
Ansys Fluent ◽  
Plant System ◽  
Type D ◽  
Experimental Apparatus ◽  
Solar Chimney Power Plant ◽  
Power Outputs

The solar chimney power plant system (abbreviated as SCPPS) is a clean and pollution-free facility for generating electric power. To improve the generating efficiency, a bank of baffles can be arranged under the collector in SCPPS. ANSYS Fluent 18.2 was used to numerically simulate 3D models of SCPPS with or without baffles, and an experimental apparatus was built for verification. There are seven different types of model discussed here: the SCPPS without baffles (prototype), and other six types of models with different baffles (a-type, b-type, c-type, d-type, e-type, and f-type). The pressure fields, temperature fields, velocity fields, and power outputs of different models under the different baffles are discussed. It is shown that the addition of baffles in the system can increase the temperature field, pressure field, velocity field, and power output to varying degrees, but b-type baffles better improve the temperature and velocity uniformity of the system, and intensify the output power. For b-type, the simulation of the systems with five different baffle numbers (3, 4, 6, 8, and 12, respectively) was carried out, and it was concluded that the system with 12 baffles is the best in improving the system performance. It can be seen that the more the number of baffles, the better the performance of SCPPS. The experiments are also verified the simulation.

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

2017 ◽  
Vol 232 (4) ◽  
pp. 503-516 ◽  
Author(s):  
Ahmed Ayadi ◽  
Zied Driss ◽  
Abdallah Bouabidi ◽  
Haithem Nasraoui ◽  
Moubarek bsisa ◽  
...  
Keyword(s):  
Power Plant ◽  
Air Flow ◽  
Thermal Characteristics ◽  
Solar Chimney ◽  
Ansys Fluent ◽  
Local Characteristics ◽  
The North ◽  
National School ◽  
Solar Chimney Power Plant ◽  
The Impact

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.

scholarly journals Modeling of Indoor Air Flow Distribution in a Naturally Ventilated Kitchen

2016 ◽  
Vol 34 (1-2) ◽  
pp. 53-64
Author(s):  
Buddhi P. Sapkota ◽  
Kedar N. Uprety ◽  
Harihar Khanal ◽  
Prakash V. Bhave
Keyword(s):  
Indoor Air ◽  
Indoor Air Pollution ◽  
Stokes Equations ◽  
Flow Distribution ◽  
Navier Stokes ◽  
Ansys Fluent ◽  
Navier Stokes Equations ◽  
Fluent Software ◽  
Computational Fluid Dynamics Cfd ◽  
Indoor Air Flow

This paper focuses on the modeling of indoor air pollution in a naturally ventilated kitchen based on the computational fluid dynamics (CFD) approach to assess its ventilation effectiveness. The 3D incompressible Navier-Stokes equations with conservation of total energy are solved numerically using ANSYS-Fluent software and the pollutant paths are investigated from the profiles of velocity, pressure, turbulent kinetic energy and temperature throughout different sections of the kitchen. Experimental verification is made through the measurement of indoor air contaminant in the same kitchen. The simulation results agree well with the on-site measured data.

scholarly journals Study the Possibility of Implementing a Solar Chimney Power Plant in Algeria (Case study: Constantine)

2021 ◽  
Vol 19 ◽  
pp. 103-108
Author(s):  
S. Djimli ◽  
◽  
A. Chaker ◽  
T.E. Boukelia ◽  
A. Ghellab ◽  
...  
Keyword(s):  
Power Plant ◽  
Rural Areas ◽  
Energy Production ◽  
Electrical Energy ◽  
Solar Irradiation ◽  
Solar Chimney ◽  
Fluent Software ◽  
Solar Chimney Power Plant ◽  
The Impact

This work offers the opportunity to consider the possibility of realizing a solar chimney power plant in the region of Constantine (Algeria). This region is characterized by its important solar radiation resource and ambient temperature. Based on actual measurements of Constantine weather station for the period of April 2020, the performance analysis of a solar chimney which have three times the dimensions of the Manzaneres prototype (Spain) is carried out using of Fluent software. The obtained results show that when the dimensions of the solar chimney are large, the impact of small changes in solar irradiation is negligible. Also, the studied power plant with dimensions of; 584 m height, a diameter of 30 m and a collector diameter of 732 m is capable of producing a monthly average of 72 to 296 MW of electrical energy, this energy production would be sufficient to meet the needs of rural areas located in this region.

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