scholarly journals Aerodynamic Characteristics of a Micro Multi-Rotor Aircraft with 12 Rotors Considering the Horizontal Wind Disturbance

2020 ◽  
Vol 10 (20) ◽  
pp. 7387
Author(s):  
Yao Lei ◽  
Wenjie Yang ◽  
Hengda Wang
Keyword(s):  
Power Consumption ◽  
Micro Air Vehicles ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Horizontal Wind ◽  
Wind Disturbance ◽  
Wind Speeds ◽  
Hover Performance ◽  
Blade Tip ◽  
Cfd Method

Wind disturbance posed difficulties for the stability of the micro air vehicles (MAVs) with attitude variation. In this paper, the aerodynamic performance of a MAV with six coaxial rotor pairs considering the horizontal wind is investigated by both experiments and numerical simulations. First, the effect of the horizontal wind on the multi-rotor aircraft is analyzed in detail. Then, low-speed wind tunnel tests were performed to obtain the thrust and power consumption and the aerodynamic performance of the multi-rotor aircraft (l/D = 1.2 and h/D = 0.19) with the rotational speed of 1500–2300 r/min in the horizontal wind ranged from 0 to 5 m/s. Finally, the distribution of streamline, the pressure of the blade tip, and the velocity and the vortices in the flow field of a multi-rotor aircraft with horizontal wind disturbance, were simulated and studied using the computational fluid dynamics (CFD) method. Through the comparison of experimental results and simulation results, it can be seen that the horizontal wind disturbance will increase power consumption to weaken the aerodynamic performance at higher rotor speeds. However, larger thrust and better hover performance are obtained at lower rotational speeds with good wind resistance. Additionally, due to the mutual induction between rotor wakes, the interactions of downwash flows become more intense at higher rotational speeds or larger wind speeds where the vortexes at the blade tip deformed and moved along with the wind.

scholarly journals The aerodynamic performance of Non-planar hex-rotors aircraft subjected the horizontal wind disturbanceLei yao1,2* Ma Chensong1 Feng Zhicheng1

2021 ◽  
Author(s):  
Lei yao ◽  
Ma Chensong ◽  
Feng Zhicheng
Keyword(s):  
Wind Speed ◽  
Power Consumption ◽  
Tilt Angle ◽  
Wind Tunnel Test ◽  
Aerodynamic Performance ◽  
Horizontal Wind ◽  
Horizontal Wind Speed ◽  
Power Loading ◽  
Experimental Values ◽  
Cfd Method

Abstract The non-planar hex-rotor aircraft mentioned in this article can change its flight status by simply changing the tilt angle of the rotor. In this paper, mainly studied the best aerodynamic performance of a non-planar hex-rotor aircraft under the influence of horizontal wind (0m/s, 2.5m/s and 4m/s). Firstly, the rotation speed of the rotor is a fixed value (2200r/min) in the low-speed wind tunnel test, the horizontal wind speed and the tilt angle of the rotor are variable values, the thrust, power consumption and power loading(PL) values of the aircraft are obtained. Secondly, the computational fluid dynamics(CFD) method is used to simulate the aerodynamic performance of a non-planar hex-rotors aircraft when subjected to a horizontal wind to obtain the simulation results. Finally, comparing the experimental values and the simulation values, it is found that the horizontal speed has a greater impact on the thrust and power consumption of the non-planar hex-rotor aircraft. From the change of PL values, it is concluded that the horizontal wind speed is 0m/s, 2.5m/s, 4m/s, the best inclination angle is 10°, 30°and 50°, and the strongest anti-wind performance.

scholarly journals Horizontal Wind Effect on the Aerodynamic Performance of Coaxial Tri-Rotor MAV

2020 ◽  
Vol 10 (23) ◽  
pp. 8612
Author(s):  
Yao Lei ◽  
Yiqiang Ye ◽  
Zhiyong Chen
Keyword(s):  
Wind Tunnel ◽  
Power Consumption ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Horizontal Wind ◽  
Wind Effect ◽  
Rotor Speed ◽  
Wind Tunnel Experiments ◽  
Air Vehicle ◽  
Power Loading

The coaxial Tri-rotor micro air vehicle (MAV) is composed of three coaxial rotors where the aerodynamic characteristics of is complicated in flight especially when the wind effect is introduced. In this paper, the hovering performance of a full-scale coaxial Tri-rotor MAV is analyzed with both the simulations and wind tunnel experiments. Firstly, the wind effect on the aerodynamic performance of coaxial Tri-rotor MAV is established with different rotor speed (1500–2300 rpm) and horizontal wind (0–4 m/s). Secondly, the thrust and power consumption of coaxial Tri-rotor (L/D = 1.6) were obtained with low-speed wind tunnel experiments. Furthermore, the streamline distribution, pressure distribution, velocity contour and vortex distribution with different horizontal wind conditions are obtained by numerical simulations. Finally, combining the experiment results and simulation results, it is noted that the horizontal wind may accelerate the aerodynamic coupling, which resulting in the greater thrust variation up to 9% of the coaxial Tri-rotor MAV at a lower rotor speed. Moreover, the aerodynamic performance is decreased with more power consumption at higher rotor speed where the wind and the downwash flow are interacted with each other. Compared with no wind flow, the shape of the downwash flow and the deformation of the vortex affect the power loading and figure of metric accordingly.

scholarly journals Aerodynamic Optimization of a Micro Quadrotor Aircraft with Different Rotor Spacings in Hover

2020 ◽  
Vol 10 (4) ◽  
pp. 1272 ◽  
Author(s):  
Yao Lei ◽  
Hengda Wang
Keyword(s):  
Numerical Simulations ◽  
Negative Impact ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Aerodynamic Optimization ◽  
Quadrotor Aircraft ◽  
Blade Tip ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Interference ◽  
Cfd Method

In order to study the aerodynamic performance of the quadrotor with different rotor spacings in hover, experiments were performed together with numerical simulations. For experimental study, an experimental platform was designed to measure the thrust and power consumption of the quadrotor with different rotor spacings (L/R = 2.2, 2.6, 3.0, 3.2, 3.6, and 4.0), and to attempt to find out the optimal rotor configuration which makes the quadrotor have the best aerodynamic performance. In addition, the pressure distribution, vorticity of the blade tip, and velocity vector of quadrotor in the flow field were obtained by Computational Fluid Dynamics (CFD) method to visually analyze the aerodynamic interference between adjacent rotors. By the comparison of experimental results and numerical simulations, the final results show that the aerodynamic performance of the quadrotor varies obviously with the change of rotor spacing, and it has a negative impact on hover efficiency if rotor spacing is too much small or large. The rotors pacing at L/R = 3.6 with larger thrust and smaller power is considered to be the best aerodynamic configuration for the quadrotor with better aerodynamic characteristics. Furthermore, compared with the isolated rotor, moderate aerodynamic interference is proved to help improve the aerodynamic performance of the quadrotor with a larger thrust, especially for a rotor spacing at L/R = 3.6.

scholarly journals Effects of Wind Disturbance on the Aerodynamic Performance of a Quadrotor MAV during Hovering

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yao Lei ◽  
Yiyong Huang ◽  
Hengda Wang
Keyword(s):  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Vertical Wind ◽  
Horizontal Wind ◽  
Wind Disturbance ◽  
Power Variation ◽  
Quadrotor Aircraft ◽  
Spacing Ratio ◽  
Power Loading ◽  
Vertical Winds

Wind disturbance could render thrust and power variation or even causing roll which is difficult to maintain a steady flight in gust especially when the horizontal or vertical wind is involved. In this paper, the horizontal wind and vertical wind are presented to study the influence of wind disturbance on aerodynamic characteristics of the quadrotor aircraft in hovering by experiments and numerical simulations. First, the simplified aerodynamic model with the wind disturbance was analyzed in detail. Also, the low-speed wind tunnel tests were performed to obtain the thrust and power variation of the quadrotor aircraft with rotor spacing ratio s = 1.1 -1.8 in both horizontal and vertical winds of 0-5 m/s with the rotational speed ranging from 1500 to 2300 rpm. Finally, the simulations are performed by utilizing the Computational Fluid Dynamics (CFD) software ANSYS to study the flow field distribution of quadrotor with the influence of the wind disturbance. The comparison between experimental results and simulation results shows that the quadrotor achieves better aerodynamic performance with larger thrust and smaller power consumption at rotor spacing ratio s = 1.8 . Additionally, the quadrotor can effectively resist the horizontal wind disturbance, which will bring larger power loading for the quadrotor, especially at 2.5 m/s. However, the vortices near blade-tip move upwards and deform with the influence of vertical wind, resulting in the reduction of thrust and aerodynamic performance of the quadrotor.

scholarly journals Optimization of aerodynamic performance for co-axial rotors with different rotor spacings

2018 ◽  
Vol 10 (4) ◽  
pp. 362-369
Author(s):  
Yao Lei ◽  
Yuxia Ji ◽  
Changwei Wang
Keyword(s):  
Power Consumption ◽  
Aerodynamic Performance ◽  
Separation Distance ◽  
Power Coefficient ◽  
Axial Thrust ◽  
Thrust Coefficient ◽  
Hover Performance ◽  
Power Loading ◽  
Blade Tip ◽  
Aerodynamic Interference

In this article, attempts are made to study the aerodynamic performance of co-axial rotors with different rotor spacings in hover. A custom-designed experimental platform with seven rotor spacings ( z/D = 0.16, 0.19, 0.23, 0.26, 0.29, 0.33 and 0.38) is applied to measure the hover performance, i.e. co-axial thrust and power consumption, and to optimize the aerodynamic configuration of the co-axial system. The experimental errors in thrust coefficient, power coefficient and power loading calculated through ‘Kline-McClintock equation’ are less than 2%. Additionally, the streamline distribution and pressure of blade tip at different rotor spacings obtained from numerical simulations are presented to visualize the effects of aerodynamic interference between the top and bottom rotor. Results show that the aerodynamic performance of a co-axial rotor with the specific rotor configure and speed range can be indeed improved by changing the rotor spacing, and the optimal performance is obtained with a rotor spacing of 0.19. Also, the magnitude of aerodynamic interference related to the axial separation distance has demonstrated to be beneficial on the total thrust and power consumption. For the same disc loading, a decrease in rotational speed results in an increase in power loading especially for z/D = 0.19. It is also found that the bottom rotor does affect the performance of the top rotor at smaller rotor spacings, whereas the effect is significantly reduced as the rotor spacing increases.

LIFT PERFORMANCE OF A CAMBERED WING FOR AERODYNAMIC PERFORMANCE ENHANCEMENT OF THE FLAPPING WING

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
H. Yusoff ◽  
N. Iswadi ◽  
A.H. Zulkifly ◽  
Sh. Mohd Firdaus ◽  
M.Z. Abdullah ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Performance Enhancement ◽  
Wind Tunnel Test ◽  
Micro Air Vehicles ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Open Circuit ◽  
Flapping Wing ◽  
Flapping Flight ◽  
Advance Ratio

Flapping-Wing Micro Air Vehicles (FW-MAVs) are small hand-held flying vehicles that can maneuver in constrained space owing to its lightweight, low aspect ratio and the ability to fly in low Reynolds number environment. In this study, the aerodynamic characteristics such as time-averaged lift of camber wings with different five wind tunnel test models with 6, 9, 12, and 15 percent camber were developed and the results were compared with time-averaged lift of a flat wing in order to assess the effects of camber wing on the aerodynamic performance for flapping flight applications. The experiments were performed in an open circuit wind tunnel with of non-return airflow with a test section of (0.3 x 0.3) m and capable of speeds from 0.5 to 30 m/s. The time-averaged lift as functions of advance ratio of the flapping motions with respect to the incoming flows are measured by using a strain gauge balance and KYOWA PCD-300A sensor interface data acquisition system. It is found that camber would bring significant aerodynamic benefits when the flapping flight is in unsteady state regime, with advance ratio less than 1.0. The aerodynamic benefits of camber are found to decay exponentially with the increasing advance ratio. Cambered wing shows significantly higher lift in comparison to the flat wing.

Load Analysis and Structure Design of Small-Scale Maglev Wind Turbine

2014 ◽  
Vol 624 ◽  
pp. 308-314
Author(s):  
Ming Xue Liu ◽  
Ye Fa Hu ◽  
Ru Hao Dong ◽  
Shi Min Peng ◽  
Hua Chun Wu
Keyword(s):  
Wind Turbine ◽  
Aerodynamic Performance ◽  
Magnetic Bearing ◽  
Friction Torque ◽  
Structure Design ◽  
Small Scale ◽  
Wind Speeds ◽  
Start Up ◽  
Load Analysis ◽  
Cfd Method

To effectively reduce friction torque and start-up wind speed, magnetic bearing was applied to the small-scale wind turbine. Load analysis is the primary task of the design for magnetic bearing in wind turbine. Based on a typical blade model, the aerodynamic performance of the impeller was simulated using Computational Fluid Dynamics (CFD) method. The characteristics and differences of the impeller’s aerodynamic performance under different wind speeds were analyzed and the aerodynamic loads were calculated as well. Moreover, the bearing capacity of magnetic bearing was calculated according to the forces on the spindle. A kind of permanent magnetic bearing (PMB) was designed for the radial supporting of the spindle in wind turbine. A prototype of the small-scale maglev wind turbine (SMWT) was presented, which provides some basis for the application of magnetic bearings in wind turbines.

scholarly journals Effect of wind disturbance on the aerodynamic performance of coaxial rotors during hovering

2019 ◽  
Vol 52 (5-6) ◽  
pp. 665-674 ◽  
Author(s):  
Yao Lei ◽  
Rongzhao Lin
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Micro Air Vehicles ◽  
Aerodynamic Performance ◽  
Vertical Wind ◽  
Wind Gust ◽  
Wind Disturbance ◽  
Wind Tunnel Tests ◽  
Coaxial Rotors ◽  
Air Vehicles

The ability to resist the effect of wind disturbance is vital for micro air vehicles. As the most compact rotor configuration for micro air vehicles, coaxial rotors will be the preferred choice for this type of devices. In this paper, the aerodynamic performance of the coaxial rotors considering the wind gust is presented with both experiments and simulations. First, effect of wind disturbances on the micro air vehicles flight was introduced. Then, low-speed wind tunnel tests were performed on a coaxial rotor with a spacing 0.39 R to obtain the performance in both horizontal and vertical wind of 0–5 m/s with the revolutions per minute ranging from 1500 to 2400. Finally, computational fluid dynamics simulations, as a means of visualizing the flow field to compensate the intuition of the experimental data, were applied by using the sliding mesh to capture the detailed interference of flow field with the distributions of streamline and velocity vector. Compared with wind tunnel tests, simulation results were highly consistent with experiments that allow to capture the flow details around the rotor tip effectively. In addition, the aerodynamic performance was deteriorated by vortices moving or deforming around the blade tip. Also, coaxial rotors can effectively resist the wind disturbance in the horizontal direction while the rotor performance was found to be declined in the vertical wind.

scholarly journals Numerical Simulation of Flow over Bionic Airfoil

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Lishu Hao ◽  
Yongwei Gao ◽  
Binbin Wei ◽  
Ke Song
Keyword(s):  
Numerical Simulation ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Curve Shape ◽  
Effective Angle ◽  
Trailing Edge Flap ◽  
Cfd Method ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Bionic Airfoil

In this study, the aerodynamic performance of bionic airfoil was numerically studied by CFD method. The bionic airfoil was represented by the combination of airfoil and a small trailing edge flap. A variety of configurations were calculated to study the effect of flap parameters, such as the flap angle, position, and shape, on the bionic airfoil aerodynamic characteristics based on two layouts which were that (1) there was a tiny gap between the airfoil and the flap and (2) there was no gap between the two. The results showed that the flap angle and position had significant effects on the aerodynamic performance of the airfoil with the two layouts. Compared with the clean airfoil, the maximum lift coefficients of the first layout and the second layout could be increased by 10.9% and 7.9%, respectively. And the effective angle of attack (AoA) range for improving the lift-to-drag ratio could reach 7°. The flap shape also affected the airfoil aerodynamic characteristics, and the flap with the sinusoid curve shape showed ideal performance.

Influence of Blade Tip Fillet Structure on Aerodynamic Performance of a Compressor Rotor

2021 ◽  
Author(s):  
HAO HAO WANG ◽  
Lei Zhao ◽  
Limin Gao ◽  
Yongzeng Li ◽  
Chi Ma
Keyword(s):  
Aerodynamic Performance ◽  
Compressor Rotor ◽  
Blade Tip
Sign in / Sign up

Export Citation Format

Share Document