scholarly journals Aerodynamic performance of a Hex-rotor unmanned aerial vehicle with different rotor spacing

2020 ◽  
Vol 53 (3-4) ◽  
pp. 711-718
Author(s):  
Yao Lei ◽  
Mingxin Cheng
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Necessary Conditions ◽  
Experimental Tests ◽  
Aerodynamic Performance ◽  
Spacing Ratio ◽  
Test Platform ◽  
Power Loading ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

In this paper, an attempt was made to obtain the aerodynamic performance of a Hex-rotor unmanned aerial vehicle with different rotor spacing. The hover efficiency of the Hex-rotor unmanned aerial vehicle is analyzed by both experimental tests and numerical simulations. First, a series of index to characterize the aerodynamic performance of the Hex-rotor unmanned aerial vehicle are analyzed theoretically, and then both tests and simulations on a Hex-rotor unmanned aerial vehicle with different rotor spacing ratio ( i = 0.50, 0.56, 0.63, 0.71, 0.83) were presented in details. For a custom-designed test platform, the thrust, power loading and hover efficiency of the Hex-rotor unmanned aerial vehicle were obtained in this paper. Finally, computational fluid dynamics simulations are performed to obtain the streamline distributions of the flow field, pressure and velocity contour of the Hex-rotor unmanned aerial vehicle. Results show that the aerodynamic performance of the Hex-rotor unmanned aerial vehicle is varied by changing the rotor spacing. Specifically, the smaller rotor spacing may improve the aerodynamic performance of the Hex-rotor unmanned aerial vehicle by increasing the rotor interferences. In the meantime, the effects of mutual interference between the rotors are gradually reduced with the increase of the rotor spacing. Moreover, the uniformity of the streamline distribution, the shape and the symmetry of the vortex are necessary conditions for the Hex-rotor unmanned aerial vehicle to generate a larger thrust. It was also noted that the thrust increased by 5.61% and the overall efficiency increased by about 8.37% at i = 0.63 for the working mode (2200 r/min), which indicated that the rotor spacing ratio at i = 0.63 obtained a best aerodynamic performance.

A computational fluid dynamics investigation of subsonic wing designs for unmanned aerial vehicle application

2019 ◽  
Vol 233 (15) ◽  
pp. 5543-5552
Author(s):  
Z Siddiqi ◽  
JW Lee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Aspect Ratio ◽  
Unmanned Aerial Vehicle ◽  
Wing Design ◽  
Ansys Fluent ◽  
High Lift ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

The wing of an unmanned aerial vehicle, RQ-7 Shadow, is modified to study the changes in the aerodynamics of the wing. The main focus is to investigate the effects of changing the components of wing design when the aircraft climbs and accelerates. These component modifications included changing the airfoil, planform, aspect ratio, and adding a winglet. Another objective is to study the efficacy of employing high-lift airfoils like the EPPLER 559 for subsonic unmanned aerial vehicle applications. For this, five wing designs are considered in this paper. Computational fluid dynamics simulations using ANSYS FLUENT® are conducted for each wing design. The C L /C D ratios for all the wings are calculated at increasing angles of attack (simulating Climbing) and increasing speed (simulating Acceleration). Compared to the NACA 4415 airfoil, which is utilized by the RQ-7 Shadow, the EPPLER 559 provides an increase in lift at the low angles of attack, but yields less of these benefits as the angle of attack increases. The tapered planform significantly reduces the high drag associated with the EPPLER 559 airfoil. The generation of higher lift forces with lower drag is further achieved by increasing the aspect ratio and through the addition of a winglet. When compared to the NACA 4415 airfoil, it is concluded that the EPPLER 559 airfoil is a viable candidate for subsonic unmanned aerial vehicle applications only when the components of wing design are altered. The performance of the wings that employ the EPPLER 559 airfoil improves when the planform is changed from rectangular to tapered, when the aspect ratio is increased and when a winglet is added.

Sea-unammned aerial vehicle takeoff characteristics analysis method based on approximate equilibrium hypothesis

2018 ◽  
Vol 233 (3) ◽  
pp. 916-927 ◽  
Author(s):  
Dongli Ma ◽  
Zhi Li ◽  
Muqing Yang ◽  
Yang Guo ◽  
Haode Hu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Unmanned Aerial Vehicle ◽  
Interpolation Method ◽  
Design Stage ◽  
Approximate Equilibrium ◽  
Characteristics Analysis ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

In this paper, transient multiphase flow computational fluid dynamics simulations based on volume of fluid model are conducted for a sea-unmanned aerial vehicle. The approximate equilibrium hypothesis is implemented after estimating the acceleration in the vertical direction. The complete configuration model and hull model are employed in simulation to predict the aerodynamic and hydrodynamic forces separately for different demands of aerodynamic and hydrodynamic computational fluid dynamics predictions and computing efficiency. In takeoff characteristics analysis, the computational fluid dynamics simulations are conducted as inputs for piecewise interpolation method. The calculated results show that the sea-unmanned aerial vehicle takeoff characteristics are totally different from a conventional aircraft. The drag-peak at hump speed is the obvious feature of the sea-unmanned aerial vehicle/seaplane. In most cases, if a sea-unmanned aerial vehicle will takeoff successfully as long as it can pass the drag peak. The takeoff distance and time calculated by piecewise interpolation method match the experimental data within 7% deviation. The accuracy is acceptable for conceptual design stage of a sea-unmanned aerial vehicle/seaplane. The results are applicable to consultation in choosing takeoff field or choosing powerplant.

Experimental tests of hybrid VTOL unmanned aerial vehicle designed for surveillance missions and operations in maritime conditions from ship‐based helipads

2021 ◽  
Author(s):  
Leszek Ambroziak ◽  
Maciej Ciężkowski ◽  
Adam Wolniakowski ◽  
Sławomir Romaniuk ◽  
Arkadiusz Bożko ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Experimental Tests ◽  
Aerial Vehicle

scholarly journals Aerodynamic Performance Estimation of Camber Morphing Airfoils for Small Unmanned Aerial Vehicle

2020 ◽  
Author(s):  
T Rajesh Senthil Kumar ◽  
Sivakumar Venugopal ◽  
Balajee Ramakrishnananda ◽  
S Vijay
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Reynolds Numbers ◽  
Aerodynamic Performance ◽  
Performance Estimation ◽  
Discrete Elements ◽  
Aerodynamic Efficiency ◽  
Design Specifications ◽  
Aerial Vehicle ◽  
Typical Design

This paper proposes a methodology to harvest the benefits of camber morphing airfoils for small unmanned aerial vehicle (SUAV) applications. Camber morphing using discrete elements was used to morph the base airfoil, which was split into two, three, and four elements, respectively, to achieve new configurations, into the target one. . In total, thirty morphed airfoil configurations were generated and tested for aerodynamic efficiency at the Reynolds numbers of 2.5 × 105 and 4.8 × 105, corresponding to loiter and cruise Reynolds numbers of a typical SUAV. The target airfoil performance could be closely achieved by combinations of 5 to 8 morphed configurations, the best of which were selected from a pool of thirty morphed airfoil configurations for the typical design specifications of SUAV. Interestingly, some morphed airfoil configurations show a reduction in drag coefficient of 1.21 to 15.17% compared to the target airfoil over a range of flight altitudes for cruise and loiter phases. Inspired by the drag reductions observed, a case study is presented for resizing a SUAV accounting for the mass addition due to the morphing system retaining the benefits of drag reduction.

scholarly journals Design and Analysis of a Rocket-Deployed Flying-Wing UAV

2021 ◽  
Author(s):  
Yukei Oyama
Keyword(s):  
Additive Manufacturing ◽  
Aspect Ratio ◽  
Unmanned Aerial Vehicle ◽  
Wing Loading ◽  
Wing Area ◽  
Power Requirement ◽  
Stability And Control ◽  
Power Loading ◽  
Aerial Vehicle ◽  
And Control

This undergraduate paper demonstrates the design, analysis, and manufacturing of a rocket deployable electric powered experimental unmanned aerial vehicle. The design process begins with defining the volume and dimensions of the allocated payload space for the UAV in the rocket. These dimensions are given by the aerostructures sub team in the Ryerson Rocketry Club. The dimensions given were used to determine the best configuration for the mission. The wing loading, power loading and endurance of the UAV are obtained from the constrained payload volume in the rocket and the avionics system of the of the UAV. The wing area, UAV weight and power requirements were calculated based on the previously determined values. The power requirement determines the motor size and propeller configuration. Aerodynamics, stability, and control were based the selected airfoil and obtained wing area. After completing the design, foam, additive manufacturing, and composite layups were used to create prototypes of the UAV. These prototypes were used to iterate the aircraft and address any immediate changes. The chosen design is a foldable flying wing, once deployed from the rocket has a wingspan of 70 inches, an aspect ratio of 13.35 and a surface area of 367 in2 . A prototype was created to prove the design feasibility of the UAV. The prototype proved to function as planned, capable of gliding, powered flight, and takeoff.

scholarly journals Design and Analysis of a Rocket-Deployed Flying-Wing UAV

2021 ◽  
Author(s):  
Yukei Oyama
Keyword(s):  
Additive Manufacturing ◽  
Aspect Ratio ◽  
Unmanned Aerial Vehicle ◽  
Wing Loading ◽  
Wing Area ◽  
Power Requirement ◽  
Stability And Control ◽  
Power Loading ◽  
Aerial Vehicle ◽  
And Control

This undergraduate paper demonstrates the design, analysis, and manufacturing of a rocket deployable electric powered experimental unmanned aerial vehicle. The design process begins with defining the volume and dimensions of the allocated payload space for the UAV in the rocket. These dimensions are given by the aerostructures sub team in the Ryerson Rocketry Club. The dimensions given were used to determine the best configuration for the mission. The wing loading, power loading and endurance of the UAV are obtained from the constrained payload volume in the rocket and the avionics system of the of the UAV. The wing area, UAV weight and power requirements were calculated based on the previously determined values. The power requirement determines the motor size and propeller configuration. Aerodynamics, stability, and control were based the selected airfoil and obtained wing area. After completing the design, foam, additive manufacturing, and composite layups were used to create prototypes of the UAV. These prototypes were used to iterate the aircraft and address any immediate changes. The chosen design is a foldable flying wing, once deployed from the rocket has a wingspan of 70 inches, an aspect ratio of 13.35 and a surface area of 367 in2 . A prototype was created to prove the design feasibility of the UAV. The prototype proved to function as planned, capable of gliding, powered flight, and takeoff.

Application of Model Predictive Control to Position and Height Limitation of a Quadrotor Unmanned Aerial Vehicle

2015 ◽  
Author(s):  
Yiqun Dong ◽  
Zhixiang Liu ◽  
Bin Yu ◽  
Youmin Zhang
Keyword(s):  
Model Predictive Control ◽  
Unmanned Aerial Vehicle ◽  
Predictive Control ◽  
Experimental Tests ◽  
Optimization Approach ◽  
Laguerre Function ◽  
Aerial Vehicle ◽  
On Line ◽  
Vehicle Position ◽  
Recursive Optimization

This paper discusses a position and height limitation control for a quadrotor UAV (Unmanned Aerial Vehicle) using Model Predictive Control (MPC) approach. Nonlinear dynamics of the quadrotor is discussed first, and decoupled linearized dynamics is obtained. For the implementation of MPC, extended state vector of vehicle is generated, and augmented linear dynamics is constructed. The MPC in this paper utilizes a set of Laguerre function as basis to approximate the future movement of modeled vehicle. Position/height constraints and vehicle actuator characteristics enter the dynamics as linearized inequalities, which could be solved on-line via a recursive optimization approach. While validations based on experimental tests will be conducted in future, currently simulations have been completed. Based on the simulation results, when state of the vehicle is laid within the permissible bound, it retains the same dynamics of original vehicle. However, if predicted response exceeds the limits, however, MPC will take effect and restrict associate vehicle states. The discussed MPC framework in this paper is considered to be applicable.

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