Electric vertical takeoff and landing aircraft and flight methods for electric vertical takeoff and landing aircraft

Abstract

To provide an electric vertical taking-off / landing aircraft and a flight method for the same, which can realize lower noise, higher fuel efficiency, and safer flight as an aircraft than conventionally.SOLUTION: The electric vertical taking-off / landing aircraft comprises: a plurality of large-diameter fan propellers 109 having large-diameter fans 110 equipped with large-diameter wings 111; a plurality of small-diameter fan propellers 300 having a plurality of small-diameter fans 310 equipped with small-diameter wings 320; and a fuselage 101 to which the large-diameter fan propellers 109 and the small-diameter fan propellers 300 are fitted. The large-diameter fan propellers 109 and the small-diameter fan propellers 300 are not provided with ducts but provided with a plurality of types of large-diameter wings 111 and small-diameter wings 320 different in diameter. The large-diameter fans 110 and the small-diameter fans 310 different in diameter rotate at different rotational speeds, and the small-diameter fan 310 smallest in diameter rotates at a highest rotational speed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric vertical takeoff and landing aircraft and a flight method for an electric vertical takeoff and landing aircraft.

Background Art

[0002] As an example of a ducted fan device that can improve thrust and suppress peeling at the lip portion, Patent Document 1 describes a plurality of fan devices having a fan that rotates around an axis to generate an air flow and a cylindrical small duct that surrounds the fan around the axis and extends in the axial direction, and a cylindrical large duct that surrounds all the fan devices. The plurality of fan devices have a central fan device and a plurality of peripheral fan devices arranged on the outer peripheral side of the small duct of the central fan device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, expectations for the social implementation of electric vertical takeoff and landing aircraft, such as small drones and flying cars, have been increasing. As a feature, there are cases where vertical takeoff and landing can be performed from an airport by a propulsion device using an axial flow fan rotationally driven by an electric motor.

[0005] As such a propulsion device, Patent Document 1 describes a plurality of fan devices having a fan that rotates around an axis to generate an air flow and a cylindrical small duct that surrounds the fan around the axis and extends in the axial direction, and a cylindrical large duct that surrounds all the fan devices.

[0006] According to Patent Document 1, thrust can be improved by using a duct. Furthermore, since peeling at the lip portion of the duct inlet can be suppressed, further thrust improvement can be expected.

[0007] However, the addition of ducts increases the aircraft's weight, which may reduce fuel efficiency, the source of its power. Furthermore, while the ducts act as a shield against the fan's aerodynamic noise, reducing noise to the sides, the noise spreads axially due to the duct opening, making noise suppression difficult.

[0008] In view of the above problems, the present invention provides an electric vertical takeoff and landing (EVTOL) aircraft and a method for flying an EVTOL aircraft that are quieter, have improved fuel efficiency as an aircraft compared to conventional aircraft, and enable safe and secure flight. [Means for solving the problem]

[0009] The present invention includes multiple means for solving the above problems, but one example is a propulsion system comprising multiple thrusters having multiple axial fans equipped with wings, and a fuselage to which the multiple thrusters are attached, wherein the multiple thrusters do not have ducts and are equipped with multiple types of axial fans having wings of different diameters. and equipped with multiple of the smallest diameter axial fans The axial fans, each with a different diameter, rotate at different rotational speeds, and the smallest diameter axial fan rotates at the highest rotational speed. Furthermore, the smallest diameter axial fan rotates only during takeoff and landing. do. [Effects of the Invention]

[0010] According to the present invention, it is possible to reduce noise, improve fuel efficiency as an aircraft, and further realize safe and secure flight. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0011] [Figure 1]This is a top view of the first embodiment of an electric vertical takeoff and landing aircraft. [Figure 2] This is a front view of the first embodiment of an electric vertical takeoff and landing aircraft. [Figure 3] This is a perspective view of the first embodiment of an electric vertical takeoff and landing aircraft. [Figure 4] This figure shows an example of the evaluation results for fan noise in the first embodiment of an electric vertical takeoff and landing aircraft. [Figure 5] This is a side view of a small fan propulsion system in an electric vertical takeoff and landing aircraft according to a second embodiment. [Figure 6] This is a front view of a small fan propulsion system in a second embodiment of an electric vertical takeoff and landing aircraft. [Modes for carrying out the invention]

[0012] Embodiments of the electric vertical takeoff and landing aircraft and the flight method for the electric vertical takeoff and landing aircraft of the present invention will be described below with reference to the drawings. In the drawings used herein, the same or corresponding components are denoted by the same or similar reference numerals, and repeated descriptions of these components may be omitted.

[0013] <First Example> A first embodiment of the electric vertical takeoff and landing aircraft and the method for flying the electric vertical takeoff and landing aircraft of the present invention will be described with reference to Figures 1 to 4.

[0014] First, the overall configuration of the electric vertical take-off and landing (EVT) aircraft will be explained using Figures 1 to 3. Figure 1 is a top view of the EVT of the first embodiment, Figure 2 is a front view thereof, and Figure 3 is a perspective view thereof.

[0015] As shown in Figure 1, the electric vertical takeoff and landing aircraft 100 is equipped with a fuselage 101, two main wings 102, one vertical stabilizer 103, two horizontal stabilizers 104, a control room 105, etc., and flies according to instructions from the control room 105.

[0016] The two main wings 102 and the two horizontal tails 104 are each attached to the fuselage 101 by wing support arms 120. Two large-diameter fan propulsion units 109 are attached to each of the main wings 102. One large-diameter fan propulsion unit 109 is attached to each of the horizontal tails 104.

[0017] The large-diameter fan propulsion unit 109 is a propulsion device in which a large-diameter fan 110 composed of a large-diameter wing 111 rotated by a large-diameter motor 112 rotates, and obtains thrust as a reaction force when the large-diameter wing 111 rotates to accelerate and discharge air. A plurality of large-diameter fan propulsion units 109 are provided on the electric vertical takeoff and landing aircraft 100, and there are a total of six in this embodiment. As shown in FIG. 1, the large-diameter fan 110 of the large-diameter fan propulsion unit 109 is configured without a duct.

[0018] As shown in FIG. 2, when the electric vertical takeoff and landing aircraft 100 is on the ground, it stops and moves by traveling on landing legs 210 from the fuselage 101. At that time, the main wings 102 and the horizontal tails 104 stand vertically with respect to the fuselage 101 as the wing support arms 120 rotate, and the large-diameter fan 110 has a posture in which the large-diameter wing 111 faces upward. When the large-diameter wing 111 rotates in the state of FIG. 2, the large-diameter fan 110 obtains thrust, so the electric vertical takeoff and landing aircraft 100 can vertically ascend.

[0019] Here, the large-diameter wing 111 generates aerodynamic noise when rotating. Among this aerodynamic noise, in particular, the frequency obtained by integrating the number of wing blades and the wing rotation speed, called the blade passing frequency, becomes a peak value on the noise spectrum and is known to be heard as an annoying abnormal sound in the surrounding environment. Furthermore, during takeoff and landing, the fan rotates at a high speed to increase thrust, which causes the blade passing frequency to shift to a certain extent to the high-frequency side. In that case, generally, a peak standing at a higher frequency than a lower frequency is more audible as an abnormal sound, so it becomes a factor of environmental degradation for the residents around the airport, and improvement is required.

[0020] Therefore, as shown in Figure 1, the electric vertical takeoff and landing aircraft 100 of this embodiment is separately equipped with one or more small-diameter fan propulsion systems 300 consisting of numerous small-diameter fans 310 attached to the fuselage 101.

[0021] In this embodiment, four small-diameter fan thrusters 300 are attached to the fuselage 101 by small-diameter fan fixing arms 301, symmetrically positioned on the longitudinal central plane of the fuselage 101, flanking the main wing 102.

[0022] Each small-diameter fan thruster 300 has a structure in which multiple small-diameter fans 310 are attached to a small-diameter fan support frame 302 connected to a small-diameter fan fixing arm 301.

[0023] As shown in Figure 3, the small-diameter fan 310 has a structure in which a small-diameter blade 320 is attached to a small-diameter motor 330 and rotates. As shown in Figure 3 and other figures, each of the small-diameter fans 310 of the small-diameter fan propulsion machine 300 is configured without a duct.

[0024] Here, when multiple large-diameter fan thrusters 109 and small-diameter fan thrusters 300 are driven, the large-diameter fans 110 and small-diameter fans 310, which have different diameters, are rotated at different rotational speeds. Furthermore, the smallest-diameter fan 310 is controlled to rotate at the highest rotational speed.

[0025] For example, it is desirable that the rotational speed of the small-diameter fan 310 with the highest rotational speed be within a range of 5 to 20 times, and more preferably 10 times, the rotational speed of the large-diameter fan 110 with the lowest rotational speed.

[0026] Furthermore, the diameter of the large-diameter blade 111 of the large-diameter fan 110 of the large-diameter fan thruster 109 is larger than the diameter of the small-diameter blade 320 of the small-diameter fan 310 of the small-diameter fan thruster 300, within a range of 5 to 20 times, and more preferably 10 times. In other words, it is desirable that the small-diameter fan 310 be about 10% smaller in diameter than the large-diameter blade 111. As a result, the peripheral speed of the blade tip at the same rotational speed becomes slower, reducing problems such as shock waves caused by the peripheral speed of the blade tip approaching the speed of sound, as well as the load on the strength, and allowing the small-diameter fan 310 to be driven at a higher rotational speed.

[0027] Furthermore, the number of large-diameter blades 111 and small-diameter blades 320 differs between the large-diameter fan thruster 109 and the small-diameter fan thruster 300, and it is desirable that the number of small-diameter blades 320 in the small-diameter fan 310 be at least twice the number of large-diameter blades 111 in the large-diameter fan 110. This will ensure sufficient thrust.

[0028] The ranges mentioned above are values ​​derived from considerations based on the specific numerical values ​​shown in Figure 4, which will be discussed later.

[0029] For example, the large-diameter fan 110 and the small-diameter fan 310 can have diameters of 1000 mm and 100 mm, the number of blades of 5 and 12 respectively, and rotational speeds of 1000 RPM and 40000 RPM.

[0030] As shown in Figure 3, a single small-diameter fan thruster 300 has a structure in which two small-diameter blades 320 are attached: an upper small-diameter blade 321 at the upper end of a small-diameter motor 330 and a lower small-diameter blade 322 at the lower end. Furthermore, the upper small-diameter blade 321 and the lower small-diameter blade 322 rotate in opposite directions. This fan configuration, in which two blades rotate simultaneously, is called a counter-rotating fan, and the direction of the airflow generated by the fan tends to be parallel to the axis, making it easier to obtain thrust. Therefore, the airflow is less likely to diffuse, and mixing of airflows discharged from adjacent small-diameter fans 310 is suppressed. As a result, it is less likely to cause a decrease in thrust efficiency that occurs when multiple small-diameter fans are rotated simultaneously.

[0031] In this embodiment, examples are given with two diameters for the thruster fan and two number of blades. However, the values ​​are not limited to these, and it is possible to increase the variations further, such as by using three or more diameters or three or more number of blades.

[0032] Figure 4 shows the results of a comparative evaluation of the fan noise of the small-diameter fan 310. The comparison target is a typical drone, a type of electric vertical take-off and landing aircraft, which is readily available and therefore easily audible.

[0033] The specifications for the drone and the small-diameter fan are as follows: diameter 240mm and 100mm, blade count 2 and 12, and rotation speed 8000 RPM and 40000 RPM, respectively. The small-diameter fan 310 has one blade.

[0034] As shown in Figure 4, the noise 401 from the drone shows a peak in noise 402, which is the wing pass frequency. The frequency is around 300 Hz, but it rises sharply from the baseline, causing discomfort to the surrounding environment as a strong, unusual noise.

[0035] On the other hand, in the noise 411 from the small-diameter fan 310, a peak occurs in the noise 412, which is the frequency at which the fan blades pass. The frequency is around 8000Hz, shifting to an ultra-high frequency. At such ultra-high frequencies above 8000Hz, although there are individual differences, auditory sensitivity decreases. Therefore, it is less likely to be recognized as an abnormal sound and is perceived as low noise, thus suppressing deterioration of the surrounding environment.

[0036] Furthermore, in the noise 411 from the small-diameter fan 310, the baseline noise is higher than the noise 401 from the drone. However, this type of broadband noise is called turbulent noise, which is generated by the high-speed rotation of the fan, and has the characteristic of not being easily perceived as an abnormal noise. Rather, it is said to be perceived as the normal operating sound of the fan and provides a sense of reassurance to those around it, so there is no problem.

[0037] It should be noted that this noise evaluation is based on the results at a single point where the noise microphone was installed, but the direction is not particularly relevant; the small-diameter fan 310 is low-noise in all directions.

[0038] The small-diameter fan propulsion system 300 secures thrust equivalent to that of a large-diameter fan 110 by installing a large number of small-diameter fans 310 in this manner. The number of small-diameter fans 310 installed in a single small-diameter fan propulsion system 300 increases or decreases depending on the size of the aircraft and the payload, ranging from about 14 fans as shown in Figure 1 to dozens or even hundreds of fans to obtain powerful thrust.

[0039] As described above, the small-diameter fan propulsion system 300 is a propulsion system that ensures low noise and thrust. However, due to its high rotational speed, it consumes a lot of energy, which may lead to increased battery consumption in the electric vertical take-off and landing aircraft 100.

[0040] Therefore, it is desirable that the small-diameter fan 310 of the small-diameter fan propulsion system 300 be driven to high speed only during takeoff and landing when noise has a significant impact on the surrounding environment, and that the high-speed rotation of the small-diameter fan 310 be stopped during flight in the air when noise has a small impact on the surrounding environment. The electric vertical takeoff and landing aircraft 100 is equipped with a main wing 102 and a horizontal tail wing 104, and thus obtains sufficient lift for flight. The large-diameter fan 110 may be stopped during takeoff and landing, or it may rotate at a low speed to supplement thrust in order to reduce the power consumption of the small-diameter fan 310. On the other hand, it is desirable that the large-diameter fan 110 be rotated at high speed while the small-diameter fan 310 is not rotated, and that thrust be obtained only from the large-diameter fan 110 during flight in the air.

[0041] Next, the effects of this embodiment will be described.

[0042] The electric vertical takeoff and landing aircraft 100 of the first embodiment of the present invention described above comprises a plurality of large-diameter fan thrusters 109 having large-diameter fans 110 equipped with large-diameter wings 111, a plurality of small-diameter fan thrusters 300 having a plurality of small-diameter fans 310 equipped with small-diameter wings 320, and a fuselage 101 to which the plurality of large-diameter fan thrusters 109 and small-diameter fan thrusters 300 are attached. The plurality of large-diameter fan thrusters 109 and small-diameter fan thrusters 300 are equipped with a plurality of types of large-diameter wings 111 and small-diameter wings 320 with different diameters, and the large-diameter fans 110 and small-diameter fans 310 with different diameters rotate at different rotational speeds, with the smallest diameter small-diameter fan 310 rotating at the highest rotational speed.

[0043] This allows the noise caused by the wing's passing frequency to be shifted to a higher frequency that is less sensitive to auditory perception, and by rotating at the highest speed, thrust can be secured. As a result, it is possible to achieve lower noise levels, improved fuel efficiency as an aircraft, and safer flight compared to conventional designs.

[0044] Furthermore, since the multiple large-diameter fan thrusters 109 and small-diameter fan thrusters 300 are equipped with multiple types that have different numbers of large-diameter blades 111 and small-diameter blades 320, it becomes easier to secure thrust.

[0045] Furthermore, by incorporating multiple of the smallest diameter fans 310, and having them all rotate only during the takeoff and landing of the electric vertical takeoff and landing aircraft 100, it is possible to achieve lower noise levels and higher power efficiency.

[0046] Furthermore, since the diameter of the largest diameter fan 110 is within a range of 5 to 20 times, and more preferably 10 times, the diameter of the smallest diameter fan 310, the peripheral speed of the blade tips can be reduced at the same rotational speed. This reduces problems such as shock waves caused by the peripheral speed of the blade tips approaching the speed of sound, as well as the load on the fan, allowing the fan to be driven at a higher rotational speed.

[0047] Furthermore, the thrust can be reliably guaranteed because the number of small-diameter blades 320 in the small-diameter fan 310, which has the most small-diameter blades 320, is more than twice the number of large-diameter blades 111 in the large-diameter fan 110, which has the fewest large-diameter blades 111.

[0048] Furthermore, by ensuring that the rotational speed of the small-diameter fan 310, which has the highest rotational speed, is within a range of 5 to 20 times, and more preferably 10 times, the rotational speed of the large-diameter fan 110, which has the lowest rotational speed, thrust can be secured while further reducing noise.

[0049] <Second Example> A second embodiment of the present invention, an electric vertical takeoff and landing (EVTOL) aircraft, and a flight method of the EVTOL aircraft will be described with reference to Figures 5 and 6. Figure 5 is a side view of the EVTOL aircraft of the second embodiment, and Figure 6 is a front view of the EVTOL aircraft of the second embodiment.

[0050] Aircraft are subjected to wind conditions during takeoff, landing, and flight, and are affected by gusts and turbulence, causing them to oscillate. This oscillation is unsafe and causes significant discomfort to passengers, so improvements are desirable.

[0051] Therefore, in the small-diameter fan propulsion system 300A of the electric vertical takeoff and landing aircraft of this embodiment, the smallest diameter fan 310 is attached to the fuselage 101 by a rotatable shaft, and the direction of the airflow created by each small-diameter fan 310 can be changed by rotation.

[0052] Specifically, as shown in Figure 5, when the small-diameter fan thruster 300A is viewed from the side, numerous small-diameter fans 310 are supported and mounted on the small-diameter fan support frame 302 by a small support motor 501. The small support motor 501 cantilever-supports the small-diameter fans 310 with respect to the small-diameter fan support frame 302.

[0053] Furthermore, the small-diameter fan 310A is rotatably fixed to the small-diameter fan support frame 302 by a small support motor 501A and is tilted 30 degrees relative to the small-diameter fan support frame 302. At this time, the airflow 510A created by the upper wing 321A and lower wing 322A of the small-diameter fan 310A is directed in the direction of the 30-degree tilt, and the thrust 520A, which is the reaction force, is also obtained at a 30-degree tilt relative to the thrust 520 from the small-diameter fan 310.

[0054] As shown in Figure 6, when the small-diameter fan thruster 300A is viewed from above, the small-diameter fan 310A rotates at an angle, resulting in a thrust of 520A. Meanwhile, the small-diameter fan 310B, located at a different position from the small-diameter fan 310A, also rotates in an angled direction, resulting in a thrust of 520B, which is a different force in a different direction from thrusts 520 and 520A. As a result, a total thrust of 610 is obtained from thrusts 520A and 520B. At this time, a reaction force is obtained against the orbital force received due to the generation of the airflow 620, and the orbital motion of the electric vertical take-off and landing aircraft is suppressed compared to the electric vertical take-off and landing aircraft 100 of Example 1.

[0055] As shown in Figure 6, in this embodiment, the small-diameter fan support frame 302 is circular, and the small-diameter fan 310 is also arranged in a circular shape. Therefore, the tilt direction of the small-diameter fan 310 is not unidirectional, but oriented in multiple directions. Consequently, the direction of the thrust 520 from the small-diameter fan 310 can also be oriented in multiple directions, allowing it to respond to airflow from multiple directions. As shown in Figure 6, two fans may be rotated to obtain a total thrust 610, or various other methods can be considered, such as rotating even more fans or using only one fan. The rotation speed of each fan may also be varied when using multiple fans.

[0056] Thus, the 300A small-diameter fan propulsion system, utilizing the 310 small-diameter fan, offers a high degree of freedom in thrust magnitude and direction, allowing it to respond to various external airflow conditions and contribute to safe and secure aviation. The selection of the fan to be used must be adapted to the external airflow conditions. External airflow conditions can be determined by sensing wind conditions along the air route, or by obtaining separately predicted wind condition forecasts in advance or during flight.

[0057] Other configurations and operations are substantially the same as those of the electric vertical takeoff and landing aircraft and the flight method of the electric vertical takeoff and landing aircraft described in the first embodiment above, and details are omitted.

[0058] In the second embodiment of the present invention, the same effects as those of the first embodiment of the present invention, the electric vertical takeoff and landing aircraft and the method of flight for the electric vertical takeoff and landing aircraft, can be obtained.

[0059] Furthermore, the smallest diameter fan 310 is attached to the fuselage 101 by a rotatable shaft, and the direction of the airflow created by each small diameter fan 310 can be changed by rotation, thus enabling safer and more secure flight.

[0060] <Other> It should be noted that the present invention is not limited to the embodiments described above, and includes various modifications. The embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described.

[0061] Furthermore, it is possible to replace parts of the configuration of one embodiment with parts of the configuration of another embodiment, and it is also possible to add parts of the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with parts of other configurations. [Explanation of Symbols]

[0062] 100: Electric Vertical Takeoff and Landing Aircraft 101: Torso 102: Main wing 103:Vertical stabilizer 104:Horizontal stabilizer 105: Control Room 109: Large-diameter fan propulsion system 110: Large diameter fan (axial flow fan) 111: Large diameter wing 112: Large diameter motor 120: Wing support arm 210: Landing gear 300, 300A: Small-diameter fan propulsion system 301: Small diameter fan mounting arm 302: Small diameter fan support frame 310, 310A, 310B: Small diameter fan (axial flow fan) 320: Small diameter wing 321: Upper small-diameter wing 321A: Upper wing 322: Lower small diameter wing 322A: Lower wing 330: Small diameter motor 401, 402: Noise (conventional) 411,412: Noise (Invention) 501, 501A: Small support motor 510A: Airflow 520,520A,520B: Thrust 610:Total thrust 620: Airflow

Claims

1. Multiple propulsion systems having multiple axial-flow fans equipped with wings, A body to which multiple thrusters are attached, The multiple propulsion units are equipped with multiple types of axial fans having different blade diameters, without ducts, and are equipped with multiple axial fans with the smallest diameter. The axial fans of different diameters rotate at different rotational speeds, and the smallest diameter axial fan rotates at the highest rotational speed. The smallest diameter axial fan rotates only during takeoff and landing. Electric vertical takeoff and landing aircraft.

2. In the electric vertical takeoff and landing aircraft according to claim 1, The multiple propulsion systems include multiple types with different numbers of blades. Electric vertical takeoff and landing aircraft.

3. In the electric vertical takeoff and landing aircraft according to claim 1, All of the smallest diameter axial fans rotate only during the takeoff and landing of the aforementioned electric vertical takeoff and landing aircraft. Electric vertical takeoff and landing aircraft.

4. In the electric vertical takeoff and landing aircraft according to claim 1, The smallest diameter axial fan is attached to the body by a rotatable shaft, and the direction of the airflow created by each of the smallest diameter axial fans can be changed by rotation. Electric vertical takeoff and landing aircraft.

5. In the electric vertical takeoff and landing aircraft according to claim 1, The diameter of the largest axial fan is within a range of 5 to 20 times the diameter of the smallest axial fan. Electric vertical takeoff and landing aircraft.

6. In the electric vertical takeoff and landing aircraft according to claim 5, The diameter of the largest axial fan is 10 times the diameter of the smallest axial fan. Electric vertical takeoff and landing aircraft.

7. In the electric vertical takeoff and landing aircraft according to claim 2, The number of blades of the axial fan with the most blades is more than twice the number of blades of the axial fan with the fewest blades. Electric vertical takeoff and landing aircraft.

8. In the electric vertical takeoff and landing aircraft according to claim 1, The rotational speed of the axial fan with the highest rotational speed is within a range of 5 to 20 times the rotational speed of the axial fan with the lowest rotational speed. Electric vertical takeoff and landing aircraft.

9. In the electric vertical takeoff and landing aircraft according to claim 8, The rotational speed of the axial fan with the highest rotational speed is 10 times the rotational speed of the axial fan with the lowest rotational speed. Electric vertical takeoff and landing aircraft.

10. A method for flying an electric vertical takeoff and landing aircraft comprising a plurality of thrusters having a plurality of axial-flow fans with wings, and a fuselage to which the plurality of said thrusters are attached, The multiple propulsion systems are provided with multiple types of axial flow fans having different blade diameters, and each of the multiple axial flow fans having the smallest diameter. Multiple of the aforementioned propulsion devices, The aforementioned axial fans of different diameters are rotated at different rotational speeds, and The smallest diameter axial fan is rotated at the highest rotational speed, The smallest diameter axial fan is rotated only during the takeoff and landing of the electric vertical takeoff and landing aircraft. The flight method of an electric vertical takeoff and landing aircraft.

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