Harvesting renewable energies through innovative kinetic honeycomb architectural facades: the mathematical & CFD modeling for wind turbine design optimization

Figures & data

Figure 1. Energy consumption in buildings by many energy resources (2010–2050).

Source: U.S. Energy Information Administration. International Energy Outlook 2019

Figure 2. World net electricity production from renewable sources (2010–2050).

Source: U.S. Energy Information Administration. International Energy Outlook 2019

Figure 3. (a) Conceptual double skin smart façade (light-pipes, wind turbines, photovoltaic cells). (b) Schematic building section-drawing showing features of light pipes, wind turbines, and photovoltaics.

Figure 4. (a) Honeycomb, bees, and honey. (b) Honeycomb smart façade module and electricity.

Figure 5. (a) Horizontal and vertical rotating propeller placement. (b) Principles of wind turbine movement in the Savonius System.

Figure 6. (a) Three Building Integrated Wind Turbine (BIWT) systems using large wind turbines. (b) Two BIWT systems use small sized wind turbines. (Source: Elger et al., 2015).

Figure 7. (a) Dimension of honeycomb windmill module. (b) Previous design of savonius wind turbine model. (c) Optimized Savonius wind turbine module with four blades.

Table 1. C_d values for different body shapes.

Type of Body		Length Ratio	Re	Cp
	Rectangular plate	l/b = 1	>10^4	1.18
		l/b = 5	>10^4	1.20
		l/b = 10	>10^4	1.30
		lb = 20	>10^4	1.50
		l/b = ∞	>10^4	1.98
	Circular Cylinder with ax parallel to flow	l/d = 0 (disk)	>10^4	1.17
		l/d = 0.5	>10^4	1.15
		l/d = 1	>10^4	0.90
		l/d = 2	>10^4	0.85
		l/d = 4	>10^4	0.87
		l/d = 8	>10^4	0.99
	Square rod	∞	>10^4	2.00
	Square rod	∞	>10^4	1.50
	Triangular cylinder	∞	>10^4	1.39
	Semicircular shell	∞	>10^4	1.20
	Semicircular shell	∞	>10^4	2.30
	Hemispherical shell		>10^4	0.39
	Hemispherical shell		>10^4	1.40
	Cube		>10^4	1.10
	Cube		>10^4	0.81
	Cone-60° vertex		>10^4	0.49
	Parachute		≈.3 × 10^7	1.20

Elger et al. (2015, 371–372)

Figure 8. Power coefficient against TSR.

Figure 9. Comparison between the simulation results of hexagonal micro wind turbine to Ferrari et al. and Blackwell et al.

Table 2. Comparison of the simulation validation result with the experiment of the Blackwell, Sheldahl, and Feltz (1977).

TSR	Simulation Validation	Error % Cp with Experiment Blackwell et al.
0.576	0.1791	10.45
0.804	0.1994	10.02
1.002	0.1883	9.43

Figure 10. (a) Savonius 3D facet 3D model. (b) Savonius 3D meshing model.

Figure 11. (a) Variation in the radius of the turbines. (b) Variation in offset of the turbines. (c) Variations in twist of the turbines.

Figure 12. (a) Vector velocity of wind flow on a 58 mm radius turbine. (b) Turbulent kinetic energy in a 58 mm radius turbine.

Figure 13. Variants of turbine blade radius.

Table 3. Variations in turbine blade radius.

Radius (mm)	TSR	CP	Power (W)	Torque (Nm)	Y Plus
57.5	0.3	0.0063	0.01414182	0.001355268	83.13049
	0.5	0.01362	0.138701848	0.004817709	132.4085
	0.6	0.00102	0.006001218	0.000208448	112.7113
58	0.3	0.12423	0.278864743	0.026724749	85.26819
	0.5	0.2786	2.837076273	0.098543809	132.8681
	0.6	0.22797	1.338171874	0.04648044	112.3835
60	0.3	0.06798	0.152605393	0.014624799	88.38058
	0.5	0.14847	1.511890424	0.052514429	134.181
	0.6	0.11964	0.702281366	0.02439324	113.8718
64	0.3	0.04071	0.091376894	0.008757022	94.81096
	0.5	0.18333	1.866906431	0.064845656	144.2127
	0.6	0.15165	0.890188959	0.030920075	122.4319
72	0.3	0.01791	0.040192929	0.003851853	102.9334
	0.5	0.22628	2.304257532	0.080036733	156.9534
	0.6	0.18799	1.10346569	0.038328089	133.3397
87.4	0.3	0.00319	0.007153723	0.000685571	111.8106
	0.5	0.00312	0.031819299	0.001105221	184.3163
	0.6	0.00266	0.015604645	0.000542016	156.7907

Figure 14. (a) Vector velocity of wind flow on an 11 mm offset turbine. (b) Turbulent kinetic energy in turbine offset 11 mm.

Figure 15. Variants of turbine blade offset (Source: Author).

Table 4. Variations in turbine blade offset.

Offset (mm)	TSR	CP	Power (W)	Torque (Nm)	Y Plus
0	0.3	0.04071	0.091377	0.008757	94.81096
	0.5	0.18333	1.866906	0.064846	144.2127
	0.6	0.15165	0.890189	0.03092	122.4319
5	0.3	0.00095	0.002122	0.000203	87.08589
	0.5	0.04072	0.414702	0.014404	132.0764
	0.6	0.00335	0.019688	0.000684	112.0743
7	0.3	0.04683	0.105127	0.010075	84.6218
	0.5	0.22955	2.337588	0.081194	128.1884
	0.6	0.17445	1.023987	0.035567	108.7234
9	0.3	0.01217	0.027321	0.002618	82.36165
	0.5	0.03606	0.367162	0.012753	124.5991
	0.6	0.00611	0.035872	0.001246	105.5825
11	0.3	0.06421	0.144118	0.013811	80.24362
	0.5	0.29918	3.046607	0.105822	121.2431
	0.6	0.250932	1.472946	0.051162	102.7176

Figure 16. (a) Vector speed of wind flow on turbine twist 0°. (b) Turbulent kinetic energy in turbine twist 0°.

Figure 17. Variants of turbine blade twist.

Table 5. Variations in turbine blade twist.

Twist (degree)	TSR	CP	Power (W)	Torque (Nm)	Y Plus
0	0.3	0.06421	0.144118	0.013811	80.24362
	0.5	0.29918	3.046607	0.105822	121.2431
	0.6	0.250932	1.472946	0.051162	102.7176
30	0.3	0.0367	0.082452702	0.00790178	73.73257
	0.5	0.15497	1.578151371	0.054815956	113.7554
	0.6	0.12406	0.728239091	0.025294862	97.44502
45	0.3	0.00339	0.007624782	0.000730714	74.97164
	0.5	0.03044	0.309972006	0.010766655	113.4298
	0.6	0.03041	0.178473013	0.006199132	96.20094
60	0.3	0.03888	0.087283209	0.008364707	72.77678
	0.5	0.1699	1.730730969	0.060115699	112.8925
	0.6	0.13926	0.817438314	0.028393134	97.33451
90	0.3	0.0441	0.099087932	0.009496002	62.60502
	0.5	0.1949	1.984248782	0.068921458	98.08689
	0.6	0.1599	0.938463598	0.03259686	85.9093

Figure 18. Hexagonal turbine optimum model.

Table 6. Variations in turbine blade TSR.

TSR	CP	Power (W)	Torque (Nm)	Y Plus
0.3	0.06421	0.144118	0.013811	80.24362
0.5	0.29918	3.046607	0.105822	121.2431
0.6	0.25093	1.472946	0.051162	102.7176

Elger, D. F., B. A. LeBret, C. T. Crowe, and J. A. Robertson. 2015 ed. Barbara, C.W. Engineering Fluid Mechanics. 9th (New York.: John Wiley & Sons)

 Google Scholar

Blackwell, B., R. Sheldahl, and L. Feltz. 1977. “Wind Tunnel Performance Data for Two and Three Bucket Savonius Rotors.” Journal of Energy 2 (3): 160–164.

 Web of Science ®Google Scholar