1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
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Thermal Analysis and Design Optimization of Solar Chimney using CFD
Ajay Singh 1, Purushottam Sahu2, Ghanshyam Dhanera 3
1 Research Scholar, BM College of Technology, Indore
2Professor and HEAD, BM College of Technology, Indore
3Example: 2AssistantProfessor, BM College of Technology, Indore, MP
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Abstract:
The solar chimney design is modeled using 3D parametric Creo design software and CFD analysis is conducted using
ANSYS simulation package. The comparative analysis is compared between straight collector design and staggered design
of solar chimney collector on the basis of air flow, thermal gradient and pressure distribution.
Keywords: Solar chimney, CFD, collectors
1. Introduction
Current power generation from fossil energies such as oil,coal, or natural gas is harmful to the atmosphere & has the
drawback of being non-renewable. Many developed countries aren't able to these conventional energy sources, & nuclear
power is considered an unnecessary risk in some of these areas. Lack of electricity has been linked to poverty,& poverty
has been linked to population increases. As a result, the need for an eco-friendly and expensive electricity generation
system is clear, and it will only become more so in the future.Solar energy is one potential solution to the ever-increasing
crisis.
1.2Concept of Solar Chimney
Schlaich [23] suggested a ‘solar chimney power plant design in the late 1970s, which could be an upright alternative to the
issues with traditional “power generators”. As shown schematically the ‘solar radiation’ is essentially absorbed by the heat
collector which is situated above the ground. As a result, the air in the reservoir heats up and radially flows inwards into a
chimney. This phenomenon is caused by difference in hydrostatic pressure of the air around the solar chimney system.
While energy extracts from the air by a turbine-driven generator situated at the bottom of the chimney.
Figure 1.1: Schematic of solar chimney
Solar chimneys can likewise be utilized in structural settings to diminish the vitality utilized by mechanical (frameworks
that warmth & cooling the working mechanical). Mechanical ventilation or cooling has been quite a long time the standard
strategy for natural control in many building composes, particularly workplaces, in created nations. Contamination and
reallocating vitality supplies have prompted another natural approach in the building plan. Inventive advances alongside
bioclimatic standards and conventional outline techniques are frequently joined to make new and possibly effective plan
arrangements. The sun-based smokestack is one of these ideas at present investigated by researchers and also architects,
for the most part through research and experimentation.

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2 Methodology Steps
The CAD model of a solar chimney is modeled as per the dimensions available in the literature [25]. The dimensions of a
solar chimney are given in table 2.1 below.
Table 2.1: Chimney Dimensions [25]
chimneyheight 200 m
chimney diameter 10 m
collector diameter 500m
Annular gap 2.5m
The CAD models of a solar chimney areindustrialized in (Creo design software). The tool used for CAD modeling of a solar
chimney is a revolving tool with material addition. Imported in ANSYS design modeler, the ‘CAD‘model created in Creo
design software is imported.
Figure 5.3: CAD model of solar chimney developed in Creo design software
The CAD modelsindustrialized in Creo are shown in figure 5.3 above. as shown in figure 5.4 below.where geometric errors
such as hard edges, corner edges, and so on are checked.
Figure 5.8: Fluid model domain definition

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Figure 5.7: Loads and Boundary conditions
The outlet and inlet conditions of the boundary are defined as shown in figure 5.7 above. The inlet boundary condition
comprises of defining air inlet speed of .05m/s and inlet heat temperature definition of 300K as shown in figure 5.8 below.
The outlet boundary condition involves the setting of relative pressure difference to 0 as no external pumping equipment
is used in the simulation.
Figure 6.10: Turbulence eddy dissipation plot of flat surface design at 800W/m2 heat flux
The turbulence eddy dissipation plot is shown in figure 6.10 above. The plot shows higher turbulence eddy dissipation
near the vertical chimney with a magnitude of .0144 m2s-3. The maximum turbulence eddy dissipation obtained from the
analysis is .0288 m2s-3. Similarly, the maximum turbulence kinetic energy obtained from simulation is observed near the
vicinity of a vertical zone with a magnitude of .002844 m2s-3. The minimum kinetic energy is observed underneath the
collector's face.
Figure 6.11: Turbulence kinetic energy plot of flat surface design at 800W/m2 heat flux

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Figure 6.12: Velocity plot of flat surface design at 800W/m2 heat flux
The velocity plot shows a higher magnitude in vertical members and a lower magnitude underneath the collector's face.
The magnitude of velocity increased suddenly at the corner and reaches 1.39m/s as shown by the green color.
6.2 Staggered Surface Results
Further CFD analysis is conducted on the staggered surface of the collector under the same loading conditions.
Figure 6.13: Pressure plot of staggered surface design at 1000W/m2 heat flux
The pressure plot generated for the flat plate collector solar chimney isshown in figures 6.13 above. The plot shows higher
pressure underneath the collector's face with a magnitude of 3.77Pa and reduces as air moves towards the inclined exit of
a chimney. The pressure at the vertical zone is .47Pa and the pressure at the common interface is 2.12Pa.
Figure 6.14: Radiation Intensity plot of staggered surface design at 1000W/m2 heat flux
The radiation intensity plot shows an almost constant distribution of radiation along the vertical zone and underneath the
flat collector type. The variation of radiation intensity is low and is observed to be highest at the vertical zone with a
magnitude of 9495 W/m2 sr-1.

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Figure 6.15: Total pressure plot of staggered surface design at 1000W/m2 heat flux
Table 6.1: Pressure variation of flat plate collector design along the curve for 1000W
Chart Count Pressure [ Pa ]
0 4.05129433
1 2.00084424
2 0.507588327
3 0.44145292
4 0.520182967
5 0.545426369
6 0.571546853
7 0.57012552
8 0.568497956
9 0.571458459
Table 6.2: Pressure variation of staggered plate collector design along the curve for 1000W
Chart Count Pressure [ Pa ]
0 2.01724315
1 -0.278381497
2 -0.269819736
3 -0.172182739
4 -0.10574311
5 -0.048026376
6 0.00562836
7 0.036296547
8 0.071661592
9 0.092241123
Table 6.3: Pressure difference
Design Type Flat Collector Design (1000W) Staggered Collector Design (1000W)
Pressure (Pa) 2.05 2.27

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Table 6.5: Pressure variation of flat plate collector design along the curve for 800W
Chart Count Pressure [ Pa ]
0 3.42269635
1 0.510040641
2 -0.290514112
3 -0.289453983
4 -0.209681213
5 -0.15196985
6 -0.103920273
7 -0.047522411
8 -0.022668351
9 0.008806961
Table 6.7: Pressure difference
Design Type Flat Collector Design (800W) Staggered Collector Design (800W)
Pressure (Pa) 2.69 2.91
7.1 Conclusion
The detailed results are:
1. The pressure profile obtained along the length of the chimney is similar for both staggered design and flat
collector design.
2. The k-epsilon turbulence model gave reasonably good predictions as the fluid flow didn’t found to be turbulent.
3. The pressure distribution along the radial direction is different for both flat plate collector chimney and staggered
design chimney.
4. For 1000W heat flux, the staggered design generated a 10.7% higher pressure drop as compared to the flat
collector design.
Chart Count Pressure [ Pa ]
0 4.422236
1 3.49484
2 1.735698
3 0.560506
4 0.371799
5 0.467921
6 0.505992
7 0.526842
8 0.558355
9 0.574641
Table 6.6: Pressure variation of staggered plate collector design along the curve for 800W

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REFERENCES
[1]. Dimoudi, A. Solar chimneys in buildings—The state of the art. Adv. Build. Energy Res. 2009, 3, 21–44.
[2]. Khanal, R.; Lei, C. Solar chimney—A passive strategy for natural ventilation. Energy Build. 2011, 43, 1811–1819.
[3]. Ohanessian, P.; Charters, W.W.S. Thermal simulation of a passive solar house using a Trombe-Michel wall structure.
Sol. Energy 1978, 20, 275–281.
[4]. Akbarzadeh, A.; Charters, W.W.S.; Lesslie, D.A. Thermocirculation characteristics of a Trombe wall passive test cell. Sol.
Energy 1982, 28, 461–468.
[5]. Das, S.K.; Kumar, Y. Design and performance of a solar dryer with vertical collector chimney suitable for rural
application. Energy Convers.Manag. 1989, 29, 129–135.
[6]. Awbi, H.B. Design considerations for naturally ventilated buildings. Renew. Energy 1994, 5, 1081–1090.
[7]. Aboulnaga, M.M. A roof solar chimney assisted by cooling cavity for natural ventilation in buildings in hot arid
climates: an energy conservation approach in Al-Ain city. Renew. Energy 1998, 14, 357–363.
[8]. Khedari, J.; Lertsatitthanakorn, C.; Pratinthong, N.; Hirunlabh, J. The modified Trombe wall: A simple ventilation means
and an efficient insulating material. Int. J. Ambient Energy 1998, 19, 104–110.
[9]. Hirunlabh, J.; Kongduang, W.; Namprakai, P.; Khedari, J. Study of natural ventilation of houses by a metallic solar wall
under tropical climate. Renew. Energy 1999, 18, 109–119.
[10]. Afonso, C.; Oliveira, A. Solar chimneys: Simulation and experiment. Energy Build. 2000, 32, 71–79.
[11]. Khedari, J.; Boonsri, B.; Hirunlabh. J. Ventilation impact of a solar chimney on indoor temperature fluctuation and air
change in a school building. Energy Build. 2000, 32, 89–93.
[12]. Spencer, S.; Chen, Z.D.; Li, Y.; Haghighat, F. Experimental investigation of a solar chimney natural ventilation system.
In Air Distribution in Rooms, Proceedings of the 7th International Roomvent Conference, Reading, UK, 9–12 July 2000; pp.
813–818.