scholarly journals Experimental Study of Rigid and Flexible Tandem Wing for Micro Aerial Vehicle

2021 ◽  
Vol 85 (2) ◽  
pp. 33-43
Author(s):  
Wan Mazlina Wan Mohamed ◽  
Mohd Azmi Ismail ◽  
Muhammad Ridzwan Ramli ◽  
Aliff Farhan Mohd Yamin ◽  
Koay Mei Hyie ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Unmanned Aerial Vehicle ◽  
Lift Coefficient ◽  
Reynolds Numbers ◽  
Micro Aerial Vehicle ◽  
Flexible Wing ◽  
Vehicle Structure ◽  
Aerial Vehicle ◽  
Wing Skin ◽  
Rigid Wing

Unmanned aerial vehicle is becoming increasingly popular each year. Now, aeronautical researchers are focusing on size minimization of unmanned aerial vehicle, especially drone and micro aerial vehicle. The lift coefficient of micro aerial vehicle has wing dimension of 12 cm and mass of less than 7 g. In the present study, with the aid of 3D printer, polylactic acid material was used to develop the micro aerial vehicle structure for tandem wing arrangement. The materials for rigid wing skin and flexible wing skin were laminating film and latex membrane, respectively. The present work elaborates the lift coefficient profiles on rigid wing skin and flexible wing skin at wing flapping frequency of 11 Hz, three different Reynolds numbers of 14000, 19000 and 24000, and five different angles of attacks between 0° and 50°. According to the results obtained, the lift coefficient decreased as the Reynolds number increased. The lift coefficient increased up to 9 as the angle of attack increased from 0° to 50° at the Reynolds number of 14000 for flexible wing skin. The results also showed that the lift coefficient of flexible wing skin was higher than that of rigid wing skin at the attack angle of10° and below, except for the Reynolds number of 14000.

The Reynolds number and flaperon deflection influence taken into account when optimizing the wing airfoil of an unmanned aerial vehicle

2020 ◽  
Author(s):  
N.I. Kochurova ◽  
Ye.S. Parkhaev ◽  
N.V. Semenchikov
Keyword(s):  
Reynolds Number ◽  
Unmanned Aerial Vehicle ◽  
Multicriteria Optimization ◽  
Lift Coefficient ◽  
Reynolds Numbers ◽  
Horizontal Flight ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Zero Values ◽  
Wing Airfoil

The paper considers the solutions to the multicriteria problem of optimizing the wing airfoil of a miniature unmanned aerial vehicle (MUAV) under various constraints. The study introduces the statement of the problem of multicriteria optimization of the airfoil shape, following the condition of MUAV horizontal flight, with an additional condition associated with a change in the flight Reynolds number of the MUAV wing. This statement of the problem allows us to optimize the airfoil, taking into account the load on the wing of the designed vehicle. The wing airfoil was optimized in a wide range of lift coefficients of Cya and Reynolds numbers. The study shows that taking into account the Reynolds number makes it possible to improve the quality of the result obtained during optimization, and introduces a technique for multicriteria optimization of the wing airfoil with sealed mechanization, i.e. with flaperon. Findings of research show that for equal values of the relative thickness, the mechanized airfoil obtained as a result of optimization has a lower center line camber (by 1.5%) than the optimized airfoil without mechanization, due to which a gain in the drag coefficient is achieved at close to zero values of the lift coefficient. The study shows how profitable the use of a wing airfoil with a flaperon on MUAV wings can be, in contrast to an airfoil without mechanization.

Numerical and experimental study of the laminar separation bubble over SS007 airfoil for micro aerial vehicles

2020 ◽  
Vol 92 (8) ◽  
pp. 1125-1131
Author(s):  
Somashekar V. ◽  
Immanuel Selwyn Raj A.
Keyword(s):  
Reynolds Number ◽  
Separation Bubble ◽  
Lift Coefficient ◽  
Laminar Separation Bubble ◽  
Micro Aerial Vehicle ◽  
Aerodynamic Efficiency ◽  
Content Type ◽  
Laminar Separation ◽  
Aerodynamic Performances ◽  
Aerial Vehicle

Purpose This paper aims to deal with the numerical investigation of laminar separation bubble (LSB) characteristics (length and height of the bubble) of SS007 airfoil at the chord Reynolds number of Rec = 0.68 × 105 to 10.28 × 105. Design/methodology/approach The numerical simulations of the flow around SS007 airfoil were carried out by using the commercial fluid dynamics (CFD) software, ANalysis system (ANSYS) 15. To solve the governing equations of the flow, a cell-centred control volume space discretisation approach is used. Wind tunnel experiments were conducted at the chord-based Reynolds number of Rec = 1.6 × 105 to validate the aerodynamic characteristics over SS007 airfoil. Findings The numerical results revealed that the LSB characteristics of a SS007 airfoil, and the aerodynamic performances are validated with experimental results. The lift and drag coefficients for both numerical and experimental results show very good correlation at Reynolds number 1.6 × 105. The lift coefficient linearly increases with the increasing angle of attack (AOA) is relatively small. The corresponding drag coefficient was found to be very small. After the formation of LSB which leads to burst to cause airfoil stall, the lift coefficient decreases and increases the drag coefficient. Practical implications Low Reynolds number and LSB characteristics concept in aerodynamics is predominant for both civilian and military applications. These include high altitude devices, wind turbines, human powered vehicles, remotely piloted vehicles, sailplanes, unmanned aerial vehicle and micro aerial vehicle. In this paper, the micro aerial vehicle flight conditions considered and investigated the LSB characteristics for different Reynolds number. To have better aerodynamic performances, it is strongly recommended to micro aerial vehicle (MAV) design engineers that the MAV is to fly at 12 m/s (cruise speed). Social implications MAVs and unmanned aerial vehicles seem to give some of the technical challenges of nature conservation monitoring and law enforcement a versatile, reliable and inexpensive solution. Originality/value The SS007 airfoil delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the drag. The maximum increase in aerodynamic efficiency is 12.5% at stall angle of attack compared to the reference airfoil at Re = 2 × 105. The results are encouraging and this airfoil could have better aerodynamic performance for the development of MAV.

Low Reynolds number flow around and heat transfer from a heated circular cylinder

2010 ◽  
Vol 1 (1-2) ◽  
pp. 15-20 ◽  
Author(s):  
B. Bolló
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Lift Coefficient ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Reynolds Number Flow ◽  
Two Dimensional Flow ◽  
Number Flow ◽  
Low Reynolds ◽  
Increasing Temperature

Abstract The two-dimensional flow around a stationary heated circular cylinder at low Reynolds numbers of 50 < Re < 210 is investigated numerically using the FLUENT commercial software package. The dimensionless vortex shedding frequency (St) reduces with increasing temperature at a given Reynolds number. The effective temperature concept was used and St-Re data were successfully transformed to the St-Reeff curve. Comparisons include root-mean-square values of the lift coefficient and Nusselt number. The results agree well with available data in the literature.

scholarly journals A Flow Analysis Using a Water Tunnel of an Innovative Unmanned Aerial Vehicle

2021 ◽  
Vol 11 (13) ◽  
pp. 5772
Author(s):  
Dawid Lis ◽  
Adam Januszko ◽  
Tadeusz Dobrocinski
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Unmanned Aerial Vehicle ◽  
Rapid Development ◽  
Lift Coefficient ◽  
Flow Analysis ◽  
Water Tunnel ◽  
Dual Use ◽  
Aerial Vehicles ◽  
Aerial Vehicle ◽  
Technical Construction

The purpose of this article is to present and discuss the results of a non-standard unnamed aerial vehicle construction with a constant cross-section square-shaped avionic profile. Based on the model’s in-air observed maneuverability, the research of avionic construction behavior was carried out in a water tunnel. The results show the model’s specific lift capabilities in comparison to classical avionic constructions. The characteristic results of the lift coefficient showed that the unmanned aerial vehicle presents favorable features than classic avionic constructions. The model was created with the prospect of using it in the future for dual-use purposes, where unmanned aerial vehicles are currently experiencing very rapid development. When creating the prototype, the focus was on low production cost, as well as convenience in operation. The development of this type of breakthrough avionic solution, which shows extraordinary maneuverability, may contribute to increasing the popularity and, above all, the availability of unmanned aerial vehicles for the largest possible group of recipients because of high avionic properties in relation to the technical construction complexity.

scholarly journals Aerodynamic Analysis of Blended Wing Body - Unmanned Aerial Vehicle (BWB-UAV) Equipped with Horizontal Stabilizers

2019 ◽  
Vol 256 ◽  
pp. 02004
Author(s):  
Nornashiha Mohd Saad ◽  
Wirachman Wisnoe ◽  
Rizal Effendy Mohd Nasir ◽  
Zurriati Mohd Ali ◽  
Ehan Sabah Shukri Askari
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Cfd Simulation ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Flight Test ◽  
Longitudinal Direction ◽  
Static Stability ◽  
Pitching Moment ◽  
Aerial Vehicle ◽  
Blended Wing Body

This paper presents an aerodynamic characteristic study in longitudinal direction of UiTM Blended Wing Body-Unmanned Aerial Vehicle Prototype (BWB-UAV Prototype) equipped with horizontal stabilizers. Flight tests have been conducted and as the result, BWB experienced overturning condition at certain angle of attack. Horizontal stabilizer was added at different location and size to overcome the issue during the flight test. Therefore, Computational Fluid Dynamics (CFD) analysis is performed at different configuration of horizontal stabilizer using Spalart - Allmaras as a turbulence model. CFD simulation of the aircraft is conducted at Mach number 0.06 or v = 20 m/s at various angle of attack, α. The data of lift coefficient (CL), drag coefficient (CD), and pitching moment coefficient (CM) is obtained from the simulations. The data is represented in curves against angle of attack to measure the performance of BWB prototype with horizontal stabilizer. From the simulation, configuration with far distance and large horizontal stabilizer gives steeper negative pitching moment slope indicating better static stability of the aircraft.

scholarly journals Design and control of the first foldable single-actuator rotary wing micro aerial vehicle

2021 ◽  
Vol 16 (6) ◽  
pp. 066019
Author(s):  
Shane Kyi Hla Win ◽  
Luke Soe Thura Win ◽  
Danial Sufiyan ◽  
Shaohui Foong
Keyword(s):  
Degrees Of Freedom ◽  
Average Power ◽  
Flight Time ◽  
Special Technique ◽  
Camera System ◽  
Micro Aerial Vehicle ◽  
Power Draw ◽  
Position Controller ◽  
Aerial Vehicle ◽  
Rigid Wing

Abstract The monocopter is a type of micro aerial vehicle largely inspired from the flight of botanical samaras (Acer palmatum). A large section of its fuselage forms the single wing where all its useful aerodynamic forces are generated, making it achieve a highly efficient mode of flight. However, compared to a multi-rotor of similar weight, monocopters can be large and cumbersome for transport, mainly due to their large and rigid wing structure. In this work, a monocopter with a foldable, semi-rigid wing is proposed and its resulting flight performance is studied. The wing is non-rigid when not in flight and relies on centrifugal forces to become straightened during flight. The wing construction uses a special technique for its lightweight and semi-rigid design, and together with a purpose-designed autopilot board, the entire craft can be folded into a compact pocketable form factor, decreasing its footprint by 69%. Furthermore, the proposed craft accomplishes a controllable flight in 5 degrees of freedom by using only one thrust unit. It achieves altitude control by regulating the force generated from the thrust unit throughout multiple rotations. Lateral control is achieved by pulsing the thrust unit at specific instances during each cycle of rotation. A closed-loop feedback control is achieved using a motion-captured camera system, where a hybrid proportional stabilizer controller and proportional-integral position controller are applied. Waypoint tracking, trajectory tracking and flight time tests were performed and analyzed. Overall, the vehicle weighs 69 g, achieves a maximum lateral speed of about 2.37 m s−1, an average power draw of 9.78 W and a flight time of 16 min with its semi-rigid wing.

Optimisation Studies for an Efficient Aerodynamic Configuration of a Blended Wing Unmanned Aerial Vehicle

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
M.K. Padmanabhan ◽  
G. Santhoshkumar ◽  
Praveen Narayan ◽  
N. Jeevaraj ◽  
M. Dinesh ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Focal Point ◽  
Lift Coefficient ◽  
Innovative Design ◽  
Aerodynamic Efficiency ◽  
Payload Capacity ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Cfd ◽  
The Cost ◽  
Long Endurance

There are various configurations and parameters that contribute to the Design of Unmanned Aerial Vehicles for specific applications. This paper deals with an innovative design of an unmanned aerial vehicle for a specified class of UAVs that require demands such as long endurance, minimized landing space with vertical take-off and landing (VTOL) capabilities. The focal point of this design is superimposing the high endurance blended wing design into tri-copter to address these parameters. The preliminary calculations are initially performed for the blended wing VTOL vehicle based on the required payload capacity and endurance. Superimposing the tri-copter will decrease the aerodynamic efficiency of the vehicle. Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical methods and algorithms to solve complex problems involving fluid flow which will effectively employed to reduce the cost and time during the conceptual and preliminary design stages. CFD analysis was carried out to estimate the major parameters like lift, drag, lift coefficient (CL) and drag coefficient (CD) for various Angle of Attack (AoA) for configurations of blended wing vehicle with and without tri-copter system in the cruise condition. Thus, the vehicle design and propulsion system is effectively optimized using this drag estimation.

scholarly journals Design and Validation of a New Morphing Camber System by Testing in the Price—Païdoussis Subsonic Wind Tunnel

Aerospace ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 23 ◽  
Author(s):  
David Communier ◽  
Ruxandra Mihaela Botez ◽  
Tony Wong
Keyword(s):  
Wind Tunnel ◽  
Unmanned Aerial Vehicle ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Trailing Edge ◽  
Subsonic Wind Tunnel ◽  
Aerial Vehicle ◽  
Stall Angle

This paper presents the design and wind tunnel testing of a morphing camber system and an estimation of performances on an unmanned aerial vehicle. The morphing camber system is a combination of two subsystems: the morphing trailing edge and the morphing leading edge. Results of the present study show that the aerodynamics effects of the two subsystems are combined, without interfering with each other on the wing. The morphing camber system acts only on the lift coefficient at a 0° angle of attack when morphing the trailing edge, and only on the stall angle when morphing the leading edge. The behavior of the aerodynamics performances from the MTE and the MLE should allow individual control of the morphing camber trailing and leading edges. The estimation of the performances of the morphing camber on an unmanned aerial vehicle indicates that the morphing of the camber allows a drag reduction. This result is due to the smaller angle of attack needed for an unmanned aerial vehicle equipped with the morphing camber system than an unmanned aerial vehicle equipped with classical aileron. In the case study, the morphing camber system was found to allow a reduction of the drag when the lift coefficient was higher than 0.48.

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