Modeling of a horizontal axis wind turbine with the QBlade simulator and NACA airfoils

Abstract

This paper proposes the modeling of a horizontal axis wind turbine (HAWT), with the QBlade simulator, using the NACA airfoils, for this purpose we use the QBlade simulator, and the NACA airfoils, scaling the geometry, in order to use the wind tunnel of the school of mines of the UNSA, with a diameter of 0.45 m, once designed with these tools, we proceed to the 3D printing of the blades in the school of Architecture of the UNSA, and the model is built, to submit it to the input variables: wind speed, air density, wind angle of attack, and as output variables angular velocity, and torque on the shaft; with these data, the information is analyzed, in order to establish the conclusions, and recommendations: The modeling with the QBlade simulator and the NACA airfoils was satisfactory, so it is recommended to use it in the design of the (HAWT).

Keywords

modeling QBlade NACA tachometer torque meter wind speed air density angle of attack

Introduction

It is evident that the wind contains energy, which can be transformed into usable energy, since time immemorial, it has been tried to optimize the way to take advantage of this energy; at present, one of the most widespread methods is the QBlade simulator with NACA airfoils. Using the wind tunnel of the UNSA School of Mines, it is proposed to validate this procedure through the systematic accumulation of input and output data, allowing the corresponding analysis, in order to conclude and recommend the pertinent (Figures 1–19).

Figure 1.

Wind actions on a static (Carta, 2009).

Figure 2.

Velocities and forces in a blade element (Carta, 2009).

Figure 3.

Wind actions on the blade (Carta, 2009).

Figure 4.

Draft angles of different segments of a blade with torsion (Carta, 2009).

Figure 5.

QBlade simulator start-up.

Figure 6.

Definition of sections (NACA 4415, circular foil).

Figure 7.

Kinematic viscosity as a function of temperature.

Figure 8.

Reynolds number calculation with Airfoil Tools (2024).

Figure 9.

Parameter input (Reynolds number).

Figure 10.

Aerodynamic analysis of NACA 4415 section in QBlade simulator.

Figure 11.

Plots of the aerodynamic analysis of the section under optimum conditions.

Figure 12.

Circular foil and NACA 4415 airfoil.

Figure 13.

Allocation of sections every 0.05 m for the formation of the flagpole.

Figure 14.

Assignment and location of sections along the blade.

Figure 15.

Design optimization by speed and angle of attack.

Figure 16.

Inclination of profiles along the blade according to Twist optimization.

Figure 17.

Wind tunnel UNSA professional school of mining engineering.

Figure 18.

Blades of the model, 3D printing length 20 cm.

Figure 19.

Rotor of the three-bladed horizontal axis wind turbine model.

Basic nomenclature:

Methodology

The procedure followed is as follows:

The free access QBlade simulator is accessed.

Wind rotor design

We start with the design by the QBlade simulator with the data of the NACA 4415 section Sijo Varghese (2017a), Sijo Varghese (2017b), Sijo Varghese (2017c), Sijo Varghese (2017f), and Sijo Varghese (2018) for which we define the sections to be used along the blade being the circular section and the NACA 4415 the ones that are part of the structure.

After that, the corresponding analysis of the section is made, for which it is necessary to calculate the Reynolds number, which relates the inertial forces and the viscosity forces, Airfoil Tools (2024), in this case we use the viscosity of the air at a temperature of 20°C.

Analytical Reynolds number calculation

Analytical calculation of the Reynolds number.

R e = \frac{v l}{v}

(3)

The design velocity is 10 m/s.

The kinematic viscosity of air at 20°C is 1.5111 × 10⁻⁵ m²/s.

The rope width to be used is 0.2 m.

R e = \frac{10 \frac{m}{s} x 0.20 m}{1.4207 x 10^{- 5} m^{2} / s}

R e = 132, 354

Within the program to evaluate the section conditions with the required conditions we enter the Reynolds number calculated with the number of transitions to be performed for the evaluation.

With the data entered, we performed the analysis of the NACA airfoil 4415 under the established conditions.

An initial blade was sized with measurements every 0.05 m along the length of the blade, thus assigning the position and defining the profile to be used.

We proceed to optimize the blade. Once the sections have been properly assigned, we optimize with an angle of attack of 8°, according to the analysis performed by the QBlade simulator, in which this result was obtained, and the Optimize for tip speed ratio of 7 because it is a three-bladed wind turbine, and a temperature of 20°C with which we are working.

Table 1 shows the Chord and Twist data with respect to the distance from the rotor to the tip of a 1-meter-long blade, obtaining the following measures of section width along the blade, and the twist in degrees in reference to the blade axis, data calculated by means of the interactions made by the simulator to obtain higher accelerations in the section with that inclination in the wind turbine.

Table 1.

Width and inclination of sections along the 1 m blade length.

Position (m)	Chord (m)	Twist (°G)
0	0.040	0.000
0.1	0.040	0.000
0.2	0.165	0.506
0.25	0.139	4.969
0.3	0.120	8.277
0.35	0.105	10.812
0.4	0.094	12.810
0.45	0.084	14.420
0.5	0.077	15.745
0.55	0.070	16.852
0.6	0.065	17.791
0.65	0.060	18.596
0.7	0.056	19.295
0.75	0.053	19.906
0.8	0.049	20.446
0.85	0.047	20.925
0.9	0.044	21.354
0.95	0.042	21.740
1	0.040	22.089

The wind tunnel is an equipment that allows to simulate the thrust of the air in one direction, this is controlled by a frequency regulator by which you can vary the speed with which it works, allows tests to evaluate the performance of the wind turbine, as a complementary part, the equipment has a thermometer and a probe to have a record of the wind speed in the tunnel.

The wind tunnel brand Airtec (2024) has a fan of 18 inches in diameter, making the conversion in centimeters are 45.7 cm. We need to obtain a free space that occupies the rotor and so that the blades do not collide with the walls of the tunnel, so it is ideal to work with 40 cm of total diameter which is the value to be used in the blades, each blade of 20 cm long, using as a basis the design to 1 m in length we proceed to scale the model to 20 cm, being the width in each position as indicated in Table 2, we must consider that the inclination of the sections would be the same because it will be provided by looking in a specific direction.

Table 2.

Width and inclination of sections along the 20 cm long blade.

Chord (cm)	Pos esc (m)	Chord esc (m)	Chord esc (cm)
4.000	0	0.0080	0.800
4.000	0.02	0.0080	0.800
16.545	0.04	0.0331	3.309
13.944	0.05	0.0279	2.789
12.017	0.06	0.0240	2.403
10.541	0.07	0.0211	2.108
9.380	0.08	0.0188	1.876
8.444	0.09	0.0169	1.689
7.675	0.1	0.0154	1.535
7.033	0.11	0.0141	1.407
6.488	0.12	0.0130	1.298
6.021	0.13	0.0120	1.204
5.617	0.14	0.0112	1.123
5.262	0.15	0.0105	1.052
4.950	0.16	0.0099	0.990
4.672	0.17	0.0093	0.934
4.424	0.18	0.0088	0.885
4.200	0.19	0.0084	0.840
3.998	0.2	0.0080	0.800

To carry out the model test in the wind tunnel, the same software is used to scale it and obtain it digitally in three dimensions having small lengths, a precision instrument is required, which can replicate the design details calculated for the wind turbine, so 3D printing was performed at the professional school of Architecture of the UNSA.

In order to test, we created a stainless-steel structure clamped with 3/8-inch clamps and bearings to support the blades during the test and to measure the angular velocity and torque.

With the blades designed and printed, the rotor ready to be mounted and the wind tunnel installed, we proceed to install the model in the wind tunnel to start taking angular velocity readings.

The tests were made with different angles of attack (α + θ) (°G) being in the first test an angle of 8° being that of the same blade so it is seen that with an air speed of 4 m per second the blades begin to rotate with that inclination of the sections, during the process we use a tachometer, thermometer and probe that allow us to take readings of angular velocity, temperature and wind speed offered by the tunnel, in addition to the frequency regulator that allows us to evaluate at different speeds, being in this case for 10 m / s about 268 r/min.

A test was also performed with (α + θ) (°G) of 30° which would be the complementary of the angle indicated by the simulator to obtain the best results, the blades rotate with higher speed than with eight degrees, obtaining results that in the 10 m/s go to 420 r/min, comparing with the previous case are 150 r/min difference between both inclinations.

Seeing the difference in these cases it was convenient to study the efficiency of the model in different inclinations to evaluate practically the angle of inclination (α + θ), so we must frequently change the angle of inclination and take measurements in each of these changes, with the help of a goniometer we must measure the inclination of the blade in reference to the axis of rotation so we make the measurements on a flat surface, the process was repeated several times to obtain an optimal angle that best exploits the results according to the simulator will be 60°.

By means of the aerodynamic analysis and the tests made of the inclination, the angular velocity measurements are taken with (α + θ) (°G) of 60, varying the frequency of the wind tunnel to submit it to different speeds, visually it reaches a point of high angular velocity, confirming that the acceleration that the blade receives with that angle is the most optimal, in this case the reading with a speed of 10 m/s is 3393.2 r/min, being much more effective than the measurements previously taken and validating the design of the wind turbine designed in the QBlade simulator.

Data and results

During the process of testing the blades at different speeds, small variability was noted in the records, so we proceeded to perform three measurements with the tachometer, to ensure the reliability of the results (Tables 3 –5).

Table 3.

Correction for air density and temperature (Kg/m³), expanded information, Airtec (2024).

Temperature	0°C	10°C	20°C	30°C	40°C	50°C	60°C	70°C	80°C	90°C	100°C
masl (mts)	0°C	10°C	20°C	30°C	40°C	50°C	60°C	70°C	80°C	90°C	100°C
0	1.077	1.039	1.004	0.971	0.94	0.911	0.883	0.858	0.834	0.811	0.789
100	1.063	1.026	0.991	0.958	0.928	0.899	0.872	0.847	0.823	0.8	0.779
200	1.05	1.013	0.978	0.946	0.916	0.887	0.861	0.836	0.812	0.79	0.769
300	1.036	1	0.966	0.934	0.904	0.876	0.85	0.825	0.802	0.78	0.759
400	1.023	0.987	0.954	0.922	0.893	0.865	0.839	0.815	0.792	0.77	0.749
500	1.018	0.982	0.949	0.917	0.888	0.861	0.835	0.81	0.788	0.766	0.745
600	0.999	0.964	0.931	0.9	0.872	0.845	0.819	0.796	0.773	0.752	0.732
700	0.987	0.952	0.919	0.889	0.861	0.834	0.809	0.786	0.763	0.742	0.722
800	0.98	0.946	0.913	0.883	0.855	0.829	0.804	0.78	0.758	0.737	0.718
900	0.964	0.93	0.898	0.869	0.841	0.815	0.791	0.768	0.746	0.725	0.706
1000	0.952	0.919	0.887	0.858	0.831	0.805	0.781	0.758	0.737	0.717	0.697
1100	0.941	0.908	0.877	0.848	0.821	0.796	0.772	0.749	0.728	0.708	0.689
1200	0.931	0.898	0.867	0.839	0.812	0.787	0.763	0.741	0.72	0.7	0.682
1300	0.92	0.888	0.857	0.829	0.803	0.778	0.755	0.733	0.712	0.692	0.674
1400	0.91	0.878	0.848	0.82	0.794	0.769	0.746	0.725	0.704	0.685	0.666
1500	0.9	0.868	0.839	0.811	0.785	0.761	0.738	0.717	0.696	0.677	0.659
1600	0.887	0.855	0.826	0.799	0.774	0.75	0.727	0.706	0.686	0.667	0.649
1700	0.874	0.843	0.814	0.787	0.762	0.739	0.716	0.696	0.676	0.657	0.64
1800	0.864	0.834	0.805	0.779	0.754	0.731	0.709	0.688	0.669	0.65	0.633
1900	0.855	0.825	0.797	0.771	0.746	0.723	0.701	0.681	0.662	0.644	0.626
2000	0.846	0.817	0.789	0.763	0.739	0.716	0.694	0.674	0.655	0.637	0.62
2100	0.838	0.808	0.781	0.755	0.731	0.708	0.687	0.667	0.648	0.63	0.614
2200	0.827	0.797	0.77	0.745	0.721	0.699	0.678	0.658	0.64	0.622	0.605
2300	0.814	0.786	0.759	0.734	0.711	0.689	0.668	0.649	0.63	0.613	0.596
2400	0.802	0.774	0.748	0.723	0.7	0.678	0.658	0.639	0.621	0.604	0.588
2500	0.793	0.765	0.739	0.715	0.692	0.671	0.651	0.632	0.614	0.597	0.581
2600	0.785	0.758	0.732	0.708	0.685	0.664	0.644	0.625	0.608	0.591	0.575
2700	0.774	0.747	0.721	0.698	0.675	0.655	0.635	0.616	0.599	0.583	0.567
2800	0.763	0.736	0.711	0.688	0.666	0.645	0.626	0.608	0.591	0.574	0.559
2900	0.753	0.726	0.702	0.678	0.657	0.637	0.617	0.6	0.583	0.567	0.551
3000	0.743	0.716	0.692	0.669	0.648	0.628	0.609	0.591	0.575	0.559	0.544
3100	0.734	0.708	0.684	0.661	0.64	0.62	0.602	0.584	0.568	0.552	0.537
3200	0.726	0.701	0.677	0.655	0.634	0.614	0.596	0.578	0.562	0.547	0.532
3300	0.719	0.694	0.67	0.648	0.627	0.608	0.59	0.573	0.556	0.541	0.527
3400	0.712	0.687	0.663	0.642	0.621	0.602	0.584	0.567	0.551	0.536	0.521
3500	0.705	0.68	0.657	0.635	0.615	0.596	0.578	0.561	0.545	0.53	0.516
3600	0.698	0.673	0.65	0.629	0.609	0.59	0.572	0.556	0.54	0.525	0.511
3700	0.691	0.667	0.644	0.623	0.603	0.584	0.567	0.55	0.535	0.52	0.506

Table 4.

Angular velocity readings with an (α + θ) (°G) of 8°.

Equipment	L1	L2	L3	Average
350	51.3	51.0	52.4	51.6
400	75.4	77.6	75.5	76.2
450	97.6	99.6	98.5	98.6
500	117.5	119.6	120.7	119.3
550	141.5	142.6	141.6	141.9
600	165.8	161.6	161.2	162.9
650	184.4	183.8	181.4	183.2
700	204.6	204.9	206.2	205.2
750	225.8	224.4	224.3	224.8
800	246.5	247.6	249.3	247.8
850	270.1	267.0	267.7	268.3
900	290.1	292.3	294.0	292.1
950	313.7	314.6	317.6	315.3
1000	335.3	333.8	337.0	335.4
1050	353.7	353.5	357.0	354.7
1100	382.6	379.6	384.1	382.1
1150	402.5	406.8	408.8	406.0
1200	428.3	431.4	432.5	430.7
1250	451.9	451.4	449.5	450.9
1300	473.1	476.2	475.0	474.8
1350	503.6	500.5	506.7	503.6
1400	526.9	532.7	526.8	528.8
1450	550.7	556.2	559.6	555.5
1500	582.7	585.7	579.6	582.7
1550	600.7	614.6	605.3	606.9
1600	631.4	633.8	626.7	630.6
1650	654.5	661.2	653.0	656.2
1700	685.8	685.5	688.8	686.7
1750	709.9	711.0	715.1	712.0

Table 5.

Rotor angular velocity with respect to tunnel wind speed (m/s) (α + θ) (°G) of 8°.

Fan (rpm)	Temperature (°C)	Speed (m/s)	Rotor (rpm)
350	22.1	4.0	51.6
400	22.1	4.6	76.2
450	22.2	5.2	98.6
500	22.2	5.9	119.3
550	22.2	6.4	141.9
600	22.2	7.2	162.9
650	22.2	7.5	183.2
700	22.2	8.4	205.2
750	22.2	8.9	224.8
800	22.2	9.5	247.8
850	22.2	10.1	268.3
900	22.2	10.8	292.1
950	22.2	11.3	315.3
1000	22.2	12.0	335.4
1050	22.3	12.7	354.7
1100	22.3	13.0	382.1
1150	22.4	13.9	406.0
1200	22.4	14.4	430.7
1250	22.5	15.0	450.9
1300	22.5	15.8	474.8
1350	22.6	16.4	503.6
1400	22.6	16.9	528.8
1450	22.7	17.6	555.5
1500	22.7	18.0	582.7
1550	22.8	18.8	606.9
1600	22.9	19.3	630.6
1650	23.0	19.7	656.2
1700	23.1	20.5	686.7
1750	23.2	20.7	712.0

First run in the wind tunnel of the UNSA School of Mines, to consider the whole range of fan rotational speeds, Sijo Varghese (2017f):

Looking for more favorable results we took (α + θ) (°G) of 30°, the complementary of the angle indicated by the simulator to obtain the results of better aerodynamic work, and we performed the data taking with that angle of inclination making first readings of the angular velocity that we can appreciate in Table 6 that increased in a medium range to the readings made with the angle of 8°.

Table 6.

Angular velocity (RPM) readings (α + θ) (°G) of 30°.

Fan	L1	L2	L3	Wind turbine
400	110.2	108.7	112.1	110.3
450	144.8	146.7	144.4	145.3
500	182.9	183.7	185.3	184.0
550	217.2	216.1	217.5	216.9
600	251.7	252.6	256.0	253.4
650	287.0	284.8	286.0	285.9
700	322.8	322.9	323.0	322.9
750	354.8	356.0	354.9	355.2
800	388.8	390.0	388.3	389.0
850	421.4	423.7	424.6	423.2
900	459.7	456.0	456.9	457.5
950	497.0	500.9	502.1	500.0
1000	534.0	536.0	537.6	535.9
1050	566.1	570.3	569.8	568.7
1100	601.2	606.4	605.5	604.4
1150	636.3	642.6	641.2	640.0
1200	671.3	678.7	676.9	675.7

We need wind speed and air temperature, data provided by the tunnel’s own probe that provides this data for every change in equipment frequency (Table 7).

Table 7.

Rotor angular velocity with respect to tunnel wind speed (m/s) (α + θ) (°G) of 30°.

Fan (rpm)	Temperature (°C)	Speed (m/s)	Wind turbine (rpm)
400	21.2	4.6	110.3
450	21.1	5.4	145.3
500	21.0	6.0	184.0
550	21.0	6.6	216.9
600	21.0	7.1	253.4
650	21.0	7.9	285.9
700	21.0	8.4	322.9
750	21.0	9.1	355.2
800	21.0	9.5	389.0
850	21.1	10.2	423.2
900	21.1	10.8	457.5
950	21.2	11.3	500.0
1000	21.2	12.1	535.9
1050	21.2	12.7	568.7
1100	21.2	13.3	604.4
1150	21.2	13.9	640.0
1200	21.2	14.6	675.7

As recorded in the first readings we see convenient to perform a series of angular velocity measurements by varying the angle (α + θ), which is what makes the blades generate the highest or lowest RPM’s, being that it is very convenient to design for the angle of 60°.

Third run, to consider the angle of attack (α), at a representative velocity of 10.2 m/s:

Based on the information in Table 8, we can see that the optimum angle, both theoretical and experimental, is very close to 60° and this is the angle at which we will begin to make the measurements by varying the wind speed (Table 9):

Table 8.

Third run, to consider the angle of attack (α), at a representative velocity of 10.2 m/s.

Angle of attack complementary to (α + θ) (°G)	Angular speed (rpm)
−8	134.6
0	123.5
8	197.1
15	340.4
30	604.2
45	1111.9
60	2878.4
65	691.5
70	163.1
75	0

Table 9.

Angular velocity (RPM) readings (α + θ) (°G) of 60°.

Fan	L1	L2	L3	Wind turbine
500	1410.4	1421.8	1427.2	1419.8
550	1700.4	1712.4	1718.1	1710.3
600	2014.9	2029.6	2035.0	2026.5
650	2317.1	2330.7	2337.7	2328.5
700	2603.7	2618.5	2626.1	2616.1
750	2876.0	2892.2	2900.0	2889.4
800	3135.6	3150.3	3159.6	3148.5
850	3379.4	3395.5	3404.7	3393.2
900	3576.2	3592.5	3602.9	3590.5
950	3799.3	3816.4	3827.3	3814.3
1000	4028.1	4047.9	4058.4	4044.8
1050	4242.2	4260.8	4272.9	4258.6
1100	4451.9	4471.6	4484.1	4469.2
1150	4658.1	4679.2	4691.9	4676.4
1200	4902.4	4922.2	4936.5	4920.4

Averaging and taking speed and temperature data we obtain the RPM values corresponding to one of the most optimal, we see a large gap between the previous readings with the current one being these higher in terms of magnitude, the data are presented in Table 10.

Table 10.

Three-bladed propeller speed versus wind speed (α + θ) (°G) of 60.

Fan (rpm)	Temperature (°C)	Speed (m/s)	Rotor (rpm)
500	22.0	5.8	1419.8
550	22.0	6.3	1710.3
600	22.0	6.8	2026.5
650	21.9	7.4	2328.5
700	21.9	7.8	2616.1
750	21.9	8.5	2889.4
800	21.9	9.2	3148.5
850	21.8	10.0	3393.2
900	21.8	10.6	3590.5
950	21.8	11.1	3814.3
1000	21.7	11.5	4044.8
1050	21.7	12.3	4258.6
1100	21.7	13.0	4469.2
1150	21.7	13.6	4676.4
1200	21.7	14.2	4920.4

Analysis

Calculation of maximum power:

P_{r} (W) = C_{p} (\frac{1}{2} ρ A υ_{1}^{3}) = {\frac{1}{2} C}_{p} ρ (\frac{π D^{2}}{4}) υ_{1}^{3}

(2)

$P_{r} (W)$ = power (W)

$C_{p}$ = power coefficient (adimensional)

$ρ$ = air density (kg/m³)

D = rotor diameter (m)

$υ$ = wind speed (m/s)

5.1. Calculation of the tip speed ratio (Manwell et al., 2010): The blades started to rotate, with a wind speed greater than 4 m/s, which verifies the recommendation, for axial shaft turbines; that the wind speed be greater than 6 m/s.

λ = \frac{Ω R}{U}

(3)

λ is tip speed ratio, adimensional.

Ω is angular velocity, (Rad/S).

R is radius, (M).

U is wind speed, (M/S).

(Tables 11 –14) With reference to Table 3.1 13 Manwell et al. (2010), interpolated, for the tip speed ratio 7.8 corresponds to a Cp, max of 0.5815, which represents in comparison with the Betz limit (0.5926), 98%.

Table 11.

Maximum power calculation.

Power coefficient (adimensional)	Air density (Kg/M3)	Rotor diameter (M)	Wind speed (M/S)	Power (watts)
0.5926	0.759	0.44	10	68.39

Table 12.

Tip speed ratio calculation.

Angular velocity, Ω (RPM)	Rotor radius, R (M)	Air velocity, U (M/S)	Angular velocity, Ω (Rad/S)	Tip speed ratio, λ (adimensional)
3393	0.22	10	355	7.8

Table 13.

Power coefficient, $C_{P, \max}$ , as a function of tip speed ratio, $λ$ ; $a_{2}$ = axial induction factor when the tip speed ratio equals the local speed ratio.

λ	$a_{2}$	$C_{P, \max}$
0.5	0.2983	0.289
1.0	0.3170	0.416
1.5	0.3245	0.477
2.0	0.3279	0.511
2.5	0.3297	0.533
5.0	0.3324	0.570
7.5	0.3329	0.581
10.0	0.3330	0.585

Table 14.

Power measured considering torque and angular velocity.

Force left (gF)	Force right (gF)	Rotor (rpm)	Force differential (gF)	Force differential (N)	Torque (Nm)	Speed, angular, rotational (rad/s)	Power (watts)
203	844	3392.8	641	6.29	0.19	355.29	67.02

As the wind tunnel walls are close to the rotor (Figures 20 –22), they cause an encapsulation, which could overestimate the efficiency of the rotor.

5.2. The blades rotated in the expected direction, considering the Lift force, according to the NACA airfoil design.

5.3. The RPM of the wind turbine model increases with reference to the complementary angle of (α + θ) being used, achieving the most favorable results at 60°.

Figure 20.

Model installed in the wind tunnel of the UNSA school of mines.

Figure 21.

Output data acquisition with an (α + θ) (°G) of 8°.

Figure 22.

Output data acquisition with an (α + θ) (°G) of 30°.

The angular velocity (rpm) (vertical), was measured for different angles of attack (α), considering also the draft angle (θ), the angle measurements were complementary (Figure 23). These tests were performed with a wind speed of 10 m/s, being optimal for the complementary angle (α+θ) of 60 sexagesimal degrees (see Table 8) (horizontal).

5.4. Power measured considering torque and angular velocity.

Figure 23.

Measurement of the angle of attack complementary to (Ω + θ), with a goniometer.

The measured power 67.02 W, with respect to the maximum power considering the Betz limit (68.39 W), a wind speed of 10 m/s and a temperature of 21.8°C; represents 98%; coinciding with that expressed in 5.1 Manwell et al. (2010).

Conclusions

The design with the QBlade simulator and the NACA airfoils is satisfactory; considering both the tip speed ratio (5.1), as well as the power measured in laboratory (5.4).

The control of the rotor rotation speed, by the wind angle of attack (pitch control), is satisfactory, for the blades designed with the QBlade simulator and the NACA airfoils, considering the optimization by the position of the sections with respect to the hub (twist) (5.3).

Recommendations

It is recommended to build a model, with one-meter blades, to test it in real conditions. As the wind tunnel walls are close to the rotor, they cause an encapsulation, which could overestimate the efficiency of the rotor; which will overcome this drawback, we are in the funding phase.

With a larger model, 2 m in diameter, it will also be possible to investigate blades with a structure, that minimize the mass and improves the start-up (Figures 24–30).

Figure 24.

Blade adjustment with screws in the indicated fixed position.

Figure 25.

Output data acquisition with an (α + θ) (°G) of 60°.

Figure 26.

Obtaining the best angle, we perform the torque measurements by means of dynamometers and in this way, we can have the necessary data to calculate the power that the model can generate.

Graph 1.

Three-bladed propeller speed versus wind speed (8°).

Graph 2.

Three-bladed propeller speed versus wind speed (30°).

Graph 3.

Three-bladed propeller speed in relation to wind speed (60°).

Graph 4.

Angular velocity (rpm) (vertical), complementary angle (α+θ) of 60 sexagesimal degrees (horizontal).

With a larger model, it will also be possible to research blades with a shape that minimizes inertia, and favors start-up at lower wind speeds.

With a larger model, it would also be possible to investigate the possible occurrence of laminar separation bubbles (LSBs), probably when operating at low Reynolds numbers.

It has been studied the use of wind energy in mechanical energy (torque and angular velocity in the shaft), it is recommended to continue the research to transform the mechanical energy in electrical energy that is of generalized use.

For horizontal axis turbines to be economically sustainable, it is recommended that they have a diameter greater than or equal to 50 m, Salas Gonzales et al. (2024).

The following papers are recommended: Tito et al. (2021), Suresh and Rajakumar (2020), Murshed et al. (2015), Khlaifat et al. (2020), Floors and Nielsen (2019), Li et al. (2020), Noronha and Krishna (2021)

Lee et al. (2016), Alaskari et al. (2019), Wood (2011), Glauert (1935), Bangga (2018), Mahmuddin (2017)

Vaz and Wood (2016), Nikhade et al. (2017), Akour et al. (2018), Liu and Janajreh (2012), Manwell et al. (2010), Burton et al. (2011), El khchine and Sriti (2021), Shoaib et al. (2019), Gasch and Twele (2012), Pourrajabian et al. (2023), Wood (2022)

Footnotes

Acknowledgements

To the Universidad Nacional de San Agustín de Arequipa, for funding this applied research, Funding Contract No. IBA-IB-29-2020-UNSA, Call 2019-1. To PhD. PE. Marcello Mariz Veiga for guiding our research, and facilitating the publication of this paper. To the Advisors: PhD. Eng. Ubaldo Yancachajlla Tito, MSc. Eng. Oswaldo Bruno Fuentes Mendoza. To the Architects of the School of Architecture of the UNSA: MSc. Arch. Hugo Cesar Gómez Tone, Architect John Bel Bustamante Escapa. To the Engineers, from the School of Mines of UNSA: MSc. Eng. Manuel Rubén Figueroa Galiano, Ing. Cristian Cesar Ortiz Olivares.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Universidad Nacional de Agustín de Arequipa (No. IBA-IB-29-2020-UNSA, Call 2019-1).

ORCID iD

José Luis Salas Gonzales

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