Journal articles: 'Aerial lifts'

1

Rasnic, Russ, Edward L. Beard, and Steven Wehmeyer. "The Evolution and Testing of Aerial Lift Anti-Entrapment Safety Devices." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 63, no. 1 (November 2019): NP1—NP5. http://dx.doi.org/10.1177/1071181319631223.

Full text

Abstract:

First introduced in the 1950’s [2], aerial lifts, also known as cherry pickers, aerial work platforms, and boom lifts, have enabled workers to perform tasks at elevated heights much easier. In many applications with overhead obstructions however, these lifts also present a severe risk to the users, often including fatality. The user can become entrapped due to unintentional involvement with overhead obstacles and be crushed between the lift and the obstacle. In this paper, we present the evolution of the common safety features and anti-entrapment devices that have been developed in response to the growing awareness of the prevalence of these injuries. After these devices are discussed, results are shown for experimental testing of potential crush mechanisms and representative forces. To test the crush force, load cells are attached to a stationary plate in front of a test dummy and forces are recorded to evaluate potential entrapment scenarios. Representative safety device designs are tested, which include mechanical, electrical, and audible features to stop and/or reverse the direction of movement to mitigate or prevent injury. All tests show that having an anti-entrapment device installed drastically reduces the risk to the user and likely prevents fatalities.

APA, Harvard, Vancouver, ISO, and other styles

2

Mastalerz, Andrzej, Paulina Szyszka, Weronika Grantham, and Jerzy Sadowski. "Biomechanical Analysis of Successful and Unsuccessful Snatch Lifts in Elite Female Weightlifters." Journal of Human Kinetics 68, no. 1 (August 21, 2019): 69–79. http://dx.doi.org/10.2478/hukin-2019-0057.

Full text

Abstract:

AbstractThe aim of this study was to identify biomechanical factors affecting successful and unsuccessful snatch attempts in elite female weightlifters during the 2013 World Weightlifting Championships. Fourteen female competitors took part in this study. Their successful and unsuccessful snatch lifts with the same load were recorded with 2 camcorders (50 Hz), and selected points were digitized manually on to the body and the barbell using the Ariel Performance Analysis System. The kinetic and kinematic barbell movement as well as the athlete’s body movement variables during the liftoff phase were examined. The results of this study show statistical differences (p ≤ 0.05) between successful and unsuccessful attempts in relation to the angle values in the knee and hip joints in preparation for the aerial phase position. Similarly, the center of gravity velocity was significantly higher in successful attempts during the catch phase. Thus, coaches should pay particular attention to the accuracy of the execution in preparation for the aerial phase position and to the velocity of the center of gravity of the competitors during the catch phase.

APA, Harvard, Vancouver, ISO, and other styles

3

Nourai, A., and N. Kolcio. "Electrical testing of insulated aerial lifts for contamination using capacitive current compensation technique." IEEE Transactions on Power Delivery 5, no. 2 (April 1990): 1054–61. http://dx.doi.org/10.1109/61.53121.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Rodriguez-Castaño, Angel, Saeed Rafee Nekoo, Honorio Romero, Rafael Salmoral, José Ángel Acosta, and Anibal Ollero. "Installation of Clip-Type Bird Flight Diverters on High-Voltage Power Lines with Aerial Manipulation Robot: Prototype and Testbed Experimentation." Applied Sciences 11, no. 16 (August 12, 2021): 7427. http://dx.doi.org/10.3390/app11167427.

Full text

Abstract:

This work presents the application of an aerial manipulation robot for the semi-autonomous installation of clip-type bird flight diverters on overhead power line cables. A custom-made prototype is designed, developed, and experimentally validated. The proposed solution aims to reduce the cost and risk of current procedures carried out by human operators deployed on suspended carts, lifts, or manned helicopters. The system consists of an unmanned aerial vehicle (UAV) equipped with a custom-made tool. This tool allows the high force required for the diverter installation to be generated; however, it is isolated from the aerial robot through a passive joint. Thus, the aerial robot stability is not compromised during the installation. This paper thoroughly describes the designed prototype and the control system for semi-autonomous operation. Flight experiments conducted in an illustrative scenario validate the performance of the system; the tests were carried out in an indoor testbed using a power line cable mock-up.

APA, Harvard, Vancouver, ISO, and other styles

5

Shahid, Farzeen, Jingshan Zhao, and Pascal Godefroit. "Aerodynamics from Cursorial Running to Aerial Gliding for Avian Flight Evolution." Applied Sciences 9, no. 4 (February 14, 2019): 649. http://dx.doi.org/10.3390/app9040649.

Full text

Abstract:

Among the different models that have been proposed to explain the origin of avian flightfrom terrestrial predators, the cursorial and arboreal hypotheses remain the most discussed.However, the fossil data at hand show that, taken separately, both theories have significantlimitations in explaining the origin of flight in bird lineage. Here, we describe an aerodynamicsprinciple that fills in the gaps between those apparently contradictory models. The upslope wind inmountain areas and strong wind in plains provided the meteorological conditions allowingfeathered paravians to glide. The results suggest that smaller, feathered paravians could be lifted toglide down to trees on mountain slopes or even to glide up to high trees in plain areas when meetinga strong airflow as they were pursuing a prey or escaping from a predator. The development ofmore aerodynamical limb feathers was a key factor for gliding down the trees because of thedependency of the resultant force on the surface area of a paravian’s body. Later in the evolutionprocess, paravians learned to change the orientation of their wings to gain higher lifts. The proposedprinciple and the results obtained in the present research help to better estimate the aerodynamicbehavior of extinct species and will also help to design an efficient and beneficial system for futureflying robots.

APA, Harvard, Vancouver, ISO, and other styles

6

Chan, Keen Ian. "Generalized Aerodynamic Optimization of Hovering Coaxial Rotor Blades." Journal of the American Helicopter Society 64, no. 2 (April 1, 2019): 1–13. http://dx.doi.org/10.4050/jahs.64.022006.

Full text

Abstract:

This paper presents the development and application of a generalized approach to the aerodynamic optimization of hovering coaxial rotors. The generalization lifts the constraints of previous theories and enables dissimilar rotor diameters, dissimilar rotational speeds, and thrust-sharing percentage of the upper and lower rotors of a coaxial pair to be incorporated as design variables. This increased versatility was necessitated by the emergence of electric vertical take-off and landing unmanned aerial vehicles, which feature independently driven rotors and have unique operational requirements. The optimization methodology begins with the derivation of the generalized momentum theory for coaxial rotors, and then extending the formulation to become an optimization technique, which determines optimal combinations of rotor diameters and rotational speeds for a specified thrust-sharing percentage. These results are next used as inputs to determine the optimal dissimilar geometries for the upper and lower rotor blades. The optimization is demonstrated on a multirotor vertical take-off and landing unmanned aerial vehicle with three coaxial pairs of rotors. The results show that a high figure of merit is achieved, and this is a contributing factor in improved hover endurance.

APA, Harvard, Vancouver, ISO, and other styles

7

Lebid, Oleksii G. "Five-mode quasilinear model of nonlinear dynamics of extended system." Environmental safety and natural resources 38, no. 2 (June 30, 2021): 104–20. http://dx.doi.org/10.32347/2411-4049.2021.2.104-120.

Full text

Abstract:

Distributed systems are widely used in practice. These are cosmic ligaments in the near-Earth space with a length of tens of kilometers. They approximate reinforced concrete piles in the soil when calculating the stress-strain state and assessing the technical condition; pipelines both in air and in liquid, underwater towed systems. Known underwater airlift systems of great length for the extraction of minerals (nodules) from the ocean floor with a length of 5-10 km. To solve the problems of the dynamics of such systems in various environments, the well-known mathematical models are not quite correct from the point of view of taking into account the variety of wave processes. It determines the need to build refined wave models. A new quasilinear mathematical model, which describes the nonlinear four-mode dynamics of the distributed system in the spatially inhomogeneous field of mass and surface forces, has been obtained. It is described by a nonlinear system of twelve first-order partial differential equations. For it, the principles of ultimate and hyperbolicity are fulfilled. Together with the boundary and initial conditions, it can be used to describe dynamics and statics of geometrically and physically nonlinear rod elements, piles in the ground, crane equipment ropes, mine lifts, aerial cableways, towed systems in liquid and gas flow, etc. For two-mode spatial reduction of the model, the theorem about correctness of Cauchy problem has been considered. As a result of the calculations, the earlier assumptions about the movement of the cable along its initial configuration were changed as the length of the cable changed. It has been found out that this assumption is only true for the initial transition participant. It is also established that at a given tachogram in the configuration of the towed line, there is a point of inflection, which shifts from top to bottom when lifting it. It can be a factor in the looping, contributing to the breakage of the cable system during towing.

APA, Harvard, Vancouver, ISO, and other styles

8

Rastgoftar, Hossein, and Ella M. Atkins. "Cooperative aerial lift and manipulation (CALM)." Aerospace Science and Technology 82-83 (November 2018): 105–18. http://dx.doi.org/10.1016/j.ast.2018.09.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Wan Mazlina Wan Mohamed, Mohd Azmi Ismail, Muhammad Ridzwan Ramli, Aliff Farhan Mohd Yamin, Koay Mei Hyie, and Hamid Yusoff. "Experimental Study of Rigid and Flexible Tandem Wing for Micro Aerial Vehicle." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 85, no. 2 (August 5, 2021): 33–43. http://dx.doi.org/10.37934/arfmts.85.2.3343.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

10

M, Abhinay, and Sampath Rao P. "Design and Analysis of an Aerial Scissor Lift." International Journal of Mechanical Engineering 1, no. 5 (May 25, 2014): 1–5. http://dx.doi.org/10.14445/23488360/ijme-v1i5p104.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Zhang, Dizhou, Zili Chen, and Junwei Lv. "Lift System Design of Tail-Sitter Unmanned Aerial Vehicle." Intelligent Control and Automation 03, no. 04 (2012): 285–90. http://dx.doi.org/10.4236/ica.2012.34033.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Arokiasami, Willson Amalraj, Prahlad Vadakkepat, and Abdullah Al Mamun. "Wingbeat Generation for a 15 DOF Flexible-Wing Aerial Vehicle Using Cosine Wave Functions." Unmanned Systems 05, no. 02 (April 2017): 115–27. http://dx.doi.org/10.1142/s230138501750008x.

Full text

Abstract:

Birds and conventional airplanes control their flight in a different manner. Conventional airplanes maneuver themselves by means of moving surfaces, while birds can bend, twist and deform their wings and adapt to unforeseen conditions such as wind gusts. However, if planes can do exactly as the birds do they can gain agility, more lift, less drag while consuming less fuel. This work aims to address this issue. Therefore, approaches of wingbeat generation for a 15 DOF flexible-wing aerial vehicle are developed in this paper. A computationally cost-effective cosine wave function-based algorithm that computes a set of wingbeats enabling the aerial vehicle to follow a desired trajectory in a realistic manner is discussed. The flexible-wing aerial vehicle is modeled similar to a seagull with an articulated skeleton. Motion of the aerial vehicle is simulated by applying joint torques and aerodynamic forces over a period of time in forward dynamics simulation. Wing and tail feather motions generate lift in the aerial vehicle, which makes it possible for the aerial vehicle to trace predefined paths. The solidworks mechanical design is used as input into Matlab SimMechanics for visualization. The results are promising for the construction of bird-like aerial vehicles.

APA, Harvard, Vancouver, ISO, and other styles

13

Lis, Dawid, Adam Januszko, and Tadeusz Dobrocinski. "A Flow Analysis Using a Water Tunnel of an Innovative Unmanned Aerial Vehicle." Applied Sciences 11, no. 13 (June 22, 2021): 5772. http://dx.doi.org/10.3390/app11135772.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

14

Hong, Dong Pyo, Byoungkuk Lee, Chan Gon Park, Seung Ho Hwang, Seok Jun You, and Yong Hong. "Composite-Insulated Boom FEM Analysis for the Application of Aerial Work Platform." Advanced Materials Research 538-541 (June 2012): 886–89. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.886.

Full text

Abstract:

Telescopic aerial boom system is used transport the object or can be used to ease working high altitude. Installation of high voltage transmission tower due to urbanization is increasing. Because working on high places such as wiring Operations and electrical maintenance has increased the demand. Boom of aerial work platform are made of steel. So, necessity for safe isolation aerial work platform used for electrical work is increasing. This paper is proposed about applied to the material used in the aerial work platform boom. Insulating material was applied to the aerial work platform the last end boom in boom system. In this paper aerial work platform boom is characterized by apply insulating material and lightweight through self-load reduction and isolation. In this paper analyzes the design of the telescopic aerial boom system of applying the insulating material using the ansys. Then design was verified through comparison of the insulation telescopic aerial lift system and Mass-produced existing telescopic aerial boom system.

APA, Harvard, Vancouver, ISO, and other styles

15

정석훈. "Development of a Vehicle Loading Lift for Various Aerial Works." Journal of the Korean Society of Mechanical Technology 12, no. 3 (September 2010): 141–46. http://dx.doi.org/10.17958/ksmt.12.3.201009.141.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Zheng, Xiang Ming. "Multi-Sensor Technique-Based Integrated Navigation and Flight Control on Aerial Robot." Applied Mechanics and Materials 511-512 (February 2014): 842–47. http://dx.doi.org/10.4028/www.scientific.net/amm.511-512.842.

Full text

Abstract:

This paper describes an unconventional overall design of eight-rotor aerial robot. An INS/GPS based Kalman Filter solution is introduced in attitude estimate to meet the high precision and reliability requirement. In order to coordinate the contradiction between high load and high frequency, we present a new control method for multi-rotor aerial robot, witch take decoupling control on lift rotors and attitude control rotors. Results of simulation and flight test show that our design on aerial robot is effective.

APA, Harvard, Vancouver, ISO, and other styles

17

V., Somashekar, and Immanuel Selwyn Raj A. "Numerical and experimental study of the laminar separation bubble over SS007 airfoil for micro aerial vehicles." Aircraft Engineering and Aerospace Technology 92, no. 8 (June 14, 2020): 1125–31. http://dx.doi.org/10.1108/aeat-12-2019-0252.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

18

Communier, David, Ruxandra Mihaela Botez, and Tony Wong. "Design and Validation of a New Morphing Camber System by Testing in the Price—Païdoussis Subsonic Wind Tunnel." Aerospace 7, no. 3 (March 7, 2020): 23. http://dx.doi.org/10.3390/aerospace7030023.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

19

Pan, Guo Jun. "Electric Scissor Aerial Work Platform Solenoid Valve Research." Applied Mechanics and Materials 380-384 (August 2013): 177–80. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.177.

Full text

Abstract:

Electric scissor aerial work platform generally uses hydraulic cylinder to lift. The decline solenoid valve is an important part of the entire hydraulic system, which usually installed in the bottom of the hydraulic cylinder. The main function is locking hydraulic cylinder to prevent the platform sinking due to its weight, protect workers safety. This paper first introduces its structure and working principle, and then does the experiments such as resistance pollutants, leakage, and a comprehensive analysis of the decline in the performance of the solenoid valve.

APA, Harvard, Vancouver, ISO, and other styles

20

Zong, Ning, Guang Jun Yang, and Sheng Li Lv. "Experimental Research on Aerodynamic Characteristics of Large Aspect Ratio Wing in Unfolding Process." Applied Mechanics and Materials 421 (September 2013): 56–61. http://dx.doi.org/10.4028/www.scientific.net/amm.421.56.

Full text

Abstract:

For an unmanned aerial vehicle, in order to study the aerodynamic characteristics of the large aspect ratio wing during the deployment process with variable sweep angles, the scaled model was tested in the wind tunnel at different angles of attack with various sweep angles of wing. Experimental results indicate that the aerodynamic configuration satisfies the cruise design requirements, providing favorable longitudinal and lateral-directional stability. Fuselage of multi-plane combination brings beneficial effect for lift. Analysis have been made on the cases including wing flow separation which lead to the step of lift curve, and the existence of longitudinal unstable range during wing unfolding, which make the foundation for next optimum of configuration. The work described in this paper can be applied in the design of unmanned aerial vehicles, missiles and other research areas.

APA, Harvard, Vancouver, ISO, and other styles

21

Ma, Chengjing, Caiwen Zhang, and Guanxiong Li. "Parametric sensitivity study of unmanned buoyancy-lifting aerial vehicle." MATEC Web of Conferences 189 (2018): 08004. http://dx.doi.org/10.1051/matecconf/201818908004.

Full text

Abstract:

Buoyancy-lifting aerial vehicle is a new development direction of the near space vehicle. This paper presents two conceptual schemes of unmanned buoyancy-lifting aerial vehicle with different configurations. The general parameter design method is studied, and the general parameter calculation model is established. The general parameters of airship and the buoyancy-lifting aerial vehicle are compared and studied. Taking buoyancy-lifting aerial vehicle with single fuselage and dual wings as the research object, sensitivity analysis of parameters has been done. The results show that compared with the airship, the weight of the buoyancylifting aerial vehicle with single fuselage and dual wings is reduced by 23.0%. Weight of the buoyancy-lifting aerial vehicle with dual fuselages and dual wings is increased by 55.3% compared with the aircraft with single fuselage. Lift- buoyancy coefficient and cruise speed have important influence on the general parameters of the aircraft. With the energy density of the battery increasing from 400Wh/kg to 600Wh/kg, weight of the aircraft is reduced by 58.5%. Compared with the airship, weight of the buoyancy-lifting aerial vehicle is more sensitive to the propeller efficiency.

APA, Harvard, Vancouver, ISO, and other styles

22

Hong, Dong Pyo, Byoung Kuk Lee, Chan Gon Park, Seung Ho Wang, Seok Jun You, and Yong Hong. "Design Optimization of Composite-Insulated Telescopic Aerial Boom." Applied Mechanics and Materials 302 (February 2013): 72–75. http://dx.doi.org/10.4028/www.scientific.net/amm.302.72.

Full text

Abstract:

Telescopic aerial boom system is used transport the object or can be used to ease working high altitude. Installation of high voltage transmission tower due to urbanization is increasing. Because working on high places such as wiring operations and electrical maintenance has increased the demand.Boom of aerial work platform are made of steel. So, necessity for safe isolation aerial work platform used for electrical work is increasing. This paper is proposed about applied to the material used in the aerial work platform boom. Insulating material was applied to the aerial work platform the last end boom in boom system. In this paper the structural analysis and formulation of the methodology for the design optimization of telescopic aerial lift boom system is presented. The main objective of the design optimization is to obtain lightweight boom system by optimizing boom cross-section shape, overlap length and plate thicknesses in the worst condition possible. The design optimization problem is formulated as minimizing the weight of the boom system. In this paper analyzes the design of the telescopic aerial boom system of applying the insulating material using the Ansys.

APA, Harvard, Vancouver, ISO, and other styles

23

Hong, Jung Min, and Jai Hak Lee. "Optimal Design of Boom Joint for 2.5 Ton Class Aerial Lift Truck." Journal of the Korean Society for Precision Engineering 35, no. 8 (August 1, 2018): 769–75. http://dx.doi.org/10.7736/kspe.2018.35.8.769.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Koo, Young-Mo, Tae-Su Seok, and Shi-Kyoon Shin. "SW05 Rotor Lift of an Unmanned Helicopter for Precise ULV Aerial Application." Journal of Biosystems Engineering 35, no. 1 (February 25, 2010): 31–36. http://dx.doi.org/10.5307/jbe.2010.35.1.031.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Boschetti, Pedro J., Elsa M. Cárdenas, and Andrea Amerio. "Increasing the Lift-Drag Ratio of an Unmanned Aerial VehicleUusing Local Twist." Journal of Aircraft 45, no. 1 (January 2008): 10–15. http://dx.doi.org/10.2514/1.33353.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Cerra, David F., and Joseph Katz. "Design of a High-Lift, Thick Airfoil for Unmanned Aerial Vehicle Applications." Journal of Aircraft 45, no. 5 (September 2008): 1789–93. http://dx.doi.org/10.2514/1.36924.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

YAMADA, Yasuyuki, Akimasa TAKAYAMA, and Taro NAKAMURA. "Development of Circulation-controlled High-lift Wing for Small Unmanned Aerial Vehicle." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2016 (2016): 1A1–18b3. http://dx.doi.org/10.1299/jsmermd.2016.1a1-18b3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Pratama, Handrico Ramelan, and Muhammad Agung Bramantya. "Numerical studies influence configuration fairing flap track airfoil type naca 4412 and naca 6412 character unmanned aerial vehicle (UAV)." MATEC Web of Conferences 197 (2018): 08017. http://dx.doi.org/10.1051/matecconf/201819708017.

Full text

Abstract:

Wings have a function of changing the air flowing into force lift, and drag. It can reduce the drag is fairing flap track, where its function can reduce the obstacles caused by the effects of compressibility, fairing flap track also has a major influence on reducing the coefficient drag on airfoil. In this study, we observed the addition of fairing flap track to airfoil, fairing inspired by Sailfish and Blue Shark fish, its fins known to have speeds of 60 km/h. The independent variable in this research is compare airfoil NACA 4412 and NACA 6412, while the dependent variable is influence of fairing flap track configuration on unmanned aerial vehicle (UAV) character by knowing coefficient lift, coefficient drag and lift to drag ratio using software computational fluid dynamic (CFD). Simulation results know that the coefficient drag airfoil NACA 4412 decreased 0.3%, coefficient lift decreased 0.5% and coefficient drag airfoil NACA 6412 also decreased 0.4%, coefficient lift decreased 0.7%. It can be concluded that the addition of fairing on airfoil is very influential in reducing the value of coefficient drag and improve the coefficient lift on airfoil.

APA, Harvard, Vancouver, ISO, and other styles

29

Luo, Si-Qi, Hui-Fang Jin, Hiroyuki Kawai, Haruo Sino, and Noboru Ōtake. "Isolation of New Saponins from the Aerial Part ofBupleurum kunmingenseY. LietS. L. Pan." Agricultural and Biological Chemistry 51, no. 6 (June 1987): 1515–19. http://dx.doi.org/10.1080/00021369.1987.10868230.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Reynolds, Andy M., and Don R. Reynolds. "Aphid aerial density profiles are consistent with turbulent advection amplifying flight behaviours: abandoning the epithet ‘passive’." Proceedings of the Royal Society B: Biological Sciences 276, no. 1654 (September 9, 2008): 137–43. http://dx.doi.org/10.1098/rspb.2008.0880.

Full text

Abstract:

Seminal field studies led by C. G. Johnson in the 1940s and 1950s showed that aphid aerial density diminishes with height above the ground such that the linear regression coefficient, b , of log density on log height provides a single-parameter characterization of the vertical density profile. This coefficient decreases with increasing atmospheric stability, ranging from −0.27 for a fully convective boundary layer to −2.01 for a stable boundary layer. We combined a well-established Lagrangian stochastic model of atmospheric dispersal with simple models of aphid behaviour in order to account for the range of aerial density profiles. We show that these density distributions are consistent with the aphids producing just enough lift to become neutrally buoyant when they are in updraughts and ceasing to produce lift when they are in downdraughts. This active flight behaviour in a weak flier is thus distinctly different from the aerial dispersal of seeds and wingless arthropods, which is passive once these organisms have launched into the air. The novel findings from the model indicate that the epithet ‘passive’ often applied to the windborne migration of small winged insects is misleading and should be abandoned. The implications for the distances traversed by migrating aphids under various boundary-layer conditions are outlined.

APA, Harvard, Vancouver, ISO, and other styles

31

Deng, Shuanghou, and Zongliang Ren. "Experimental study of a ducted contra-rotating lift fan for vertical/short takeoff and landing unmanned aerial vehicle application." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, no. 16 (September 18, 2017): 3108–17. http://dx.doi.org/10.1177/0954410017731441.

Full text

Abstract:

This study explores the aerodynamic characteristics of a ducted contra-rotating lift fan for vertical/short takeoff and landing application by means of force, pressure, and flow field measurements. The effect of rotating frequency and contra-locomotion on the force generation was examined using a miniature six-component force sensor. Additionally, for the sake of considering the ground effect, the flow field at the exit was investigated using high-response pressure measurement. Results revealed that the lift shows a quadratic generation trend on increasing the r/min where the inherent unsteady flow contradicts the conventional quasi-steady model of propeller. The contra-rotating mechanism can significantly augment the lift while still being lower than double single rotors. The unsteadiness of the contra-rotating rotors is quite obvious where two high-pressure regions are revealed and rotate. When the lift fan approaches the ground, the lift will be augmented significantly due to the surplus of the wake jet.

APA, Harvard, Vancouver, ISO, and other styles

32

Guerra-Langan, Ana, Sergio Araujo-Estrada, and Shane Windsor. "Unmanned aerial vehicle control costs mirror bird behaviour when soaring close to buildings." International Journal of Micro Air Vehicles 12 (January 2020): 175682932094100. http://dx.doi.org/10.1177/1756829320941005.

Full text

Abstract:

Small unmanned aerial vehicles (SUAVs) are suitable for many low-altitude operations in urban environments due to their manoeuvrability; however, their flight performance is limited by their on-board energy storage and their ability to cope with high levels of turbulence. Birds exploit the atmospheric boundary layer in urban environments, reducing their energetic flight costs by using orographic lift generated by buildings. This behaviour could be mimicked by fixed-wing SUAVs to overcome their energy limitations if flight control can be maintained in the increased turbulence present in these conditions. Here, the control effort required and energetic benefits for a SUAV flying parallel to buildings whilst using orographic lift was investigated. A flight dynamics and control model was developed for a powered SUAV and used to simulate flight control performance in different turbulent wind conditions. It was found that the control effort required decreased with increasing altitude and that the mean throttle required increased with greater radial distance to the buildings. However, the simulations showed that flying close to the buildings in strong wind speeds increased the risk of collision. Overall, the results suggested that a strategy of flying directly over the front corner of the buildings appears to minimise the control effort required for a given level of orographic lift, a strategy that mirrors the behaviour of gulls in high wind speeds.

APA, Harvard, Vancouver, ISO, and other styles

33

Suarez, Alejandro, Manuel Perez, Guillermo Heredia, and Anibal Ollero. "Cartesian Aerial Manipulator with Compliant Arm." Applied Sciences 11, no. 3 (January 22, 2021): 1001. http://dx.doi.org/10.3390/app11031001.

Full text

Abstract:

This paper presents an aerial manipulation robot consisting of a hexa-rotor equipped with a 2-DOF (degree of freedom) Cartesian base (XY–axes) that supports a 1-DOF compliant joint arm that integrates a gripper and an elastic linear force sensor. The proposed kinematic configuration improves the positioning accuracy of the end effector with respect to robotic arms with revolute joints, where each coordinate of the Cartesian position depends on all the joint angles. The Cartesian base reduces the inertia of the manipulator and the energy consumption since it does not need to lift its own weight. Consequently, the required torque is lower and, thus, the weight of the actuators. The linear and angular deflection sensors of the arm allow the estimation, monitoring and control of the interaction wrenches exerted in two axes (XZ) at the end effector. The kinematic and dynamic models are derived and compared with respect to a revolute-joint arm, proposing a force-position control scheme for the aerial robot. A battery counterweight mechanism is also incorporated in the X–axis linear guide to partially compensate for the motion of the manipulator. Experimental results indoors and outdoors show the performance of the robot, including object grasping and retrieval, contact force control, and force monitoring in grabbing situations.

APA, Harvard, Vancouver, ISO, and other styles

34

Siddiqi, Z., and JW Lee. "A computational fluid dynamics investigation of subsonic wing designs for unmanned aerial vehicle application." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 15 (June 3, 2019): 5543–52. http://dx.doi.org/10.1177/0954410019852553.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

35

Henry, Todd C., John T. Hrynuk, and Francis R. Phillips. "Assessment of 3D-printed span change structures applied to small unmanned aerial vehicles." International Journal of Micro Air Vehicles 13 (January 2021): 175682932199213. http://dx.doi.org/10.1177/1756829321992139.

Full text

Abstract:

An assessment of 3D-printed span-change structures is presented for determining suitability of the technology to small unmanned aerial vehicles. Materials and manufacturing technologies were used with an emphasis on near term applicability with design trades between the aerodynamic performance and structural response. Aerodynamic performance was assessed on three wind tunnel models varying span (432, 600, and 762 mm), wind speed (Reynolds numbers 18,000, 36,000, and 71,000), additive manufacturing print build plane and camber, quantifying structural response as the resulting shape during aerodynamic loading. Each model displayed increasing compliance as span increased with wing-tip displacement on the order of 50, 100, and 200 mm with various degrees of sweep and twist. Models generated excess lift at Re = 71,000 indicating potential flight demonstration of the technology with a lift to drag improvement of up to 97% at maximum wing extension.

APA, Harvard, Vancouver, ISO, and other styles

36

Raeisi, Bahram, and Hekmat Alighanbari. "Simulation and analysis of flow around tilting asymmetric ducted fans mounted at the wing tips of a vertical take-off and landing unmanned aerial vehicle." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, no. 15 (July 3, 2017): 2870–97. http://dx.doi.org/10.1177/0954410017716954.

Full text

Abstract:

Tilting ducted fans attached to the wing tips of vertical take-off and landing unmanned aerial vehicles define new applications for these types of aerial vehicles. This new configuration gives vertical take-off and landing unmanned aerial vehicles the ability to hover like helicopters and fly forward like airplanes, which results in using any arbitrary location for take-off and landing combined with increasing range and speed. Furthermore, generating additional lift using asymmetrical shape for the external body of the ducted fans can lead to reducing the wing area and related overall drag, which results in saving more energy. This research provides experimental results from wind tunnel tests in addition to computational fluid dynamics simulations to investigate the advantages of using an asymmetrical tilting ducted fan instead of a symmetrical one. “actuator disk model” combined with the assumption of “constant delivered power” to the propeller were used successfully to calculate the induced velocity to the rotor plane of the ducted fan in the computational fluid dynamics simulations. The effects of the stall and flow separation on the aerodynamic coefficients were also studied and compared for the symmetrical and asymmetrical ducted fans. Both computational fluid dynamics and experimental results showed noticeable improvement in the lift coefficient using an asymmetrical shape for the external body of the tilting ducted fans.

APA, Harvard, Vancouver, ISO, and other styles

37

Korchagin, N. N., and I. Yu Vladimirov. "On the effect of circulatory flow around objects in marine medium and atmosphere." Доклады Академии наук 488, no. 2 (September 24, 2019): 207–11. http://dx.doi.org/10.31857/s0869-56524882207-211.

Full text

Abstract:

Analytical expressions of the hydrodynamic reaction of a point dipole in two-layer circulatory fluid flow around it are obtained. The dependence of the wave resistance and the lift force on the flow velocity, the density jump, the circulation and the depth of the sea is investigated. It is shown that the influence of the velocity circulation leads to a change in the lift force acting on the dipole. Moreover, such changes are reversible in a relatively narrow range of the velocity of flow around the pipeline. Along with the pipeline, such features in the nature of the effect of circulation on the lift force can be manifested for self-propelled underwater objects and aerial vehicles.

APA, Harvard, Vancouver, ISO, and other styles

38

Hu, Yu Jen, Ya Ting Tsai, Ming Chi Tsai, Ching Ho Yen, and Jyh Bin Ke. "The Study of Carrier of Aerial Afforestation Design." Applied Mechanics and Materials 157-158 (February 2012): 1097–103. http://dx.doi.org/10.4028/www.scientific.net/amm.157-158.1097.

Full text

Abstract:

In this study, we use the single-winged seeds flying model to study the relevant parameters. Afforestation used as sowing carrier stay in the air spill design to improve sowing distance. This study is further implemented the method currently carried out by Forestry Bureau for afforestation and soil conservation. This study is funded by the relevant principles of fluid dynamics to explore: physical analysis of the five seeds. Reads as follows: (1) structure and trajectory, (2) advance ratio, (3) lift thrust vs. pitch angle, (4) loading vs. terminal velocity, (5) cut-off angle area.. Finally, this study design some carrier models for testing. Spill sowing the spacing and the drift distance experiment analysis results. With experimental data, (shown in Table 2). This research used easy materials that you can make a lot. Fluid mechanical principles could be excellent learning materials for children to explore the use of teaching aids.

APA, Harvard, Vancouver, ISO, and other styles

39

Pan, Christopher S., Alan Hoskin, Michael McCann, Mei-Li Lin, Kevin Fearn, and Paul Keane. "Aerial lift fall injuries: A surveillance and evaluation approach for targeting prevention activities." Journal of Safety Research 38, no. 6 (January 2007): 617–25. http://dx.doi.org/10.1016/j.jsr.2007.08.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

DWIVEDI, Y. D., Vasishta BHARGAVA, P. M. V. RAO, and Donepudi JAGADEESH. "Aerodynamic Performance of Micro Aerial Wing Structures at Low Reynolds Number." INCAS BULLETIN 11, no. 1 (March 5, 2019): 107–20. http://dx.doi.org/10.13111/2066-8201.2019.11.1.8.

Full text

Abstract:

Corrugations are folds on a surface as found on wings of dragon fly insects. Although they fly at relatively lower altitudes its wings are adapted for better aerodynamic and aero-elastic characteristics. In the present work, three airfoil geometries were studied using the 2-D panel method to evaluate the aerodynamic performance for low Reynolds number. The experiments were conducted in wind tunnel for incompressible flow regime to demonstrate the coefficients of lift drag and glide ratio at two Reynolds numbers 1.9x104 and 1.5x105 and for angles of attack ranging between 00 and 160. The panel method results have been validated using the current and existing experiment data as well as with the computational work from cited literature. A good agreement between the experimental and the panel methods were found for low angles of attack. The results showed that till 80 angle of attack higher lift coefficient and lower drag coefficient are obtainable for corrugated airfoils as compared to NACA 0010. The validation of surface pressure coefficients for all three airfoils using the panel method at 40 angles of attack was done. The contours of the non-dimensional pressure and velocity are illustrated from -100 to 200 angles of attack. A good correlation between the experiment data and the computational methods revealed that the corrugated airfoils exhibit better aerodynamic performance than NACA 0010.

APA, Harvard, Vancouver, ISO, and other styles

41

Temesgen, By H., V. M. LeMay, K. L. Froese, and P. L. Marshall. "Imputing tree-lists from aerial attributes for complex stands of south-eastern British Columbia." Forest Ecology and Management 177, no. 1-3 (April 2003): 277–85. http://dx.doi.org/10.1016/s0378-1127(02)00321-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Li, Yi, Yang Zhang, and Junqiang Bai. "Numerical Simulation of the Aerodynamic Influence of Aircrafts During Aerial Refueling with Engine Jet." International Journal of Aeronautical and Space Sciences 21, no. 1 (September 9, 2019): 15–24. http://dx.doi.org/10.1007/s42405-019-00212-2.

Full text

Abstract:

Abstract Aerial refueling technology has been widely applied in various fields and it is one of the hotspots but difficulties for the aeronautical technologies. DLR-F6 WBNP model is used as a tanker and a fighter model is used as a receiver. The flow field of Probe–Drogue refueling and Flying Boom refueling is numerically simulated using the Reynolds-averaged Navier–Stokes equations, and the effects of the jet flow and the aerodynamic characteristics of the receiver are taken into consideration. The results indicate that the effect of downwash of the tanker reduces the lift coefficient and decreases the pitching moment coefficient of the receiver. The jet flow of tanker increases the dynamic pressure while decreases the local angle of attack, which increases the pressure difference between the upper and lower surfaces of receiver. Compared with the results without jet, the jet flow can increase the lift and the drag of the receiver and reduces the pitching moment, and even cause the change of rolling moment direction. Therefore, engine jet is an important factor when simulating aerial refueling.

APA, Harvard, Vancouver, ISO, and other styles

43

Nguyen, Tien Dat, Subhan Sdywaliva, and Taufiq Mulyanto. "Modeling of Wing Flapping Motion." Applied Mechanics and Materials 842 (June 2016): 132–40. http://dx.doi.org/10.4028/www.scientific.net/amm.842.132.

Full text

Abstract:

In flying animal world, there are different flapping motions to produce lift and thrust depending on their species and size. Recent development in Unmanned Aerial Vehicle had tried to mimic flying animal. Rather than having two separate systems in providing lift and thrust, the wing upstroke and downstroke movement combined with wing twisting produce the necessary lift and thrust. Insects and some small birds have even the ability to fly hover.The present study is focused on the modeling of wing flapping motion. Instead of only accommodating flapping motion in a vertical plane and spanwise pitching motion, the model permits to include wing lead-lag motion in the horizontal plane. This more degree of freedom permit to model more complex wing flapping motion.

APA, Harvard, Vancouver, ISO, and other styles

44

Witcher, Kenneth L., Ian R. McAndrew, and Elena Vishnevskaya. "Take-off characteristics for NACA 4612 aerofoil in a twin-wing configuration with optimum angles of attack." MATEC Web of Conferences 189 (2018): 10029. http://dx.doi.org/10.1051/matecconf/201818910029.

Full text

Abstract:

Unmanned Aerial Vehicles are used generally at low levels and speeds. The research reported in this article investigates the possible use of twin-wing designs for higher altitudes with a focus on the possible lift capable for either short runways or high payloads. The wing aerofoil and unique Angles of Attack, AoA, are set 5o on the upper wing and 10o on the lower. There is a positive upper wing stagger of 50% of the chord length at height separation of 1 chord. These parameters have been established from previous research and this research investigates how they generate lift at take-off and what lift and drag properties exist. It also determines if these parameters are in-line with those for high altitude flight.

APA, Harvard, Vancouver, ISO, and other styles

45

Harithuddin, Ahmad Salahuddin Mohd, Mohd Fazri Sedan, Syaril Azrad Md Ali, Shattri Mansor, Hamid Reza Jifroudi, Siti Noradzam Adam, and Zailani Khuzaimah. "LIGHTER-THAN-AIR (LTA) UNMANNED AERIAL SYSTEM (UAS) CARRIER CONCEPT FOR SURVAILLANCE AND DISASTER MANAGEMENT." Seminar Nasional Geomatika 3 (February 15, 2019): 1255. http://dx.doi.org/10.24895/sng.2018.3-0.1051.

Full text

Abstract:

Unmanned aerial systems (UAS) has many advantages in the fields of SURVAILLANCE and disaster management compared to space-borne observation, manned missions and in situ methods. The reasons include cost effectiveness, operational safety, and mission efficiency. This has in turn underlined the importance of UAS technology and highlighted a growing need in a more robust and efficient unmanned aerial vehicles to serve specific needs in SURVAILLANCE and disaster management. This paper first gives an overview on the framework for SURVAILLANCE particularly in applications of border control and disaster management and lists several phases of SURVAILLANCE and service descriptions. Based on this overview and SURVAILLANCE phases descriptions, we show the areas and services in which UAS can have significant advantage over traditional methods.

APA, Harvard, Vancouver, ISO, and other styles

46

Liu, Yun, Zhi Sheng Jing, Shan Chao Tu, Ming Hao Yu, and Guo Wei Qin. "Character Measurement of Flapping-Wing Mechanism." Applied Mechanics and Materials 48-49 (February 2011): 300–303. http://dx.doi.org/10.4028/www.scientific.net/amm.48-49.300.

Full text

Abstract:

The characteristics and the application prospect are analyzed. It is concluded that bionic flapping-wing flying has better lift fore generation efficiency, which is the development trend of aerial vehicles. By the scaling effect analysis on bionic flying mechanism, it is presented that bionic flying could be realized more easily when the sizes are decreased. In this article, the flying mechanism of inset and Aves was studied and the high lift force mechanism of flapping-winging was concluded. In order to make the flapping-flying easier, we design a new type flapping-flying mechanism. A set of flapping-wing move comparatively. It can provide lift force all the time. We test the lift force in the condition of different speed and different frequency. The lift effect is validated on a simple suspend flight device. An experimental platform to measure the aerodynamic force is devised and developed by ourselves. On this equipment, the aerodynamics force of the prototype is test. The result is that enhancing speed or frequency can improve lift force in evidence

APA, Harvard, Vancouver, ISO, and other styles

47

Kasem, Abdelrahman, Ahmad Gamal, Amr Hany, Hesham Gaballa, Karim Ahmed, Mina Romany, Mohamed Abdelkawy, and Mohamed M. Abdelrahman. "Design and implementation of an unmanned aerial vehicle with self-propulsive wing." Advances in Mechanical Engineering 11, no. 6 (June 2019): 168781401985729. http://dx.doi.org/10.1177/1687814019857299.

Full text

Abstract:

The article aims to prove the effectiveness of the proposed unmanned air vehicle design (The Propulsive Wing) through numerical and experimental means. The propulsive wing unmanned air vehicle is a completely new class of unmanned air vehicle, making disruptive changes in the aircraft industry. It is based on a distributed cross-flow electric fan propulsion system. When the fan starts to operate, the flow is drawn from the suction surface, provided by energy through the fan and expelled out of the airfoil trailing edge (TE). This causes a significant lift increase and drag reduction with respect to ordinary aircrafts, making it perfect for applications requiring low cruise speed such as firefighting, agriculture, and aerial photography. In this early stage of the investigation, our main aim is to prove that this design is applicable and the expected aerodynamic and propulsion improvements are achievable. This is done through a two-dimensional computational fluid dynamics investigation of the flow around an airfoil with an embedded cross-flow fan near its TE. A scaled wind tunnel model of the same geometry used in the computational fluid dynamics investigation was manufactured and used to perform wind tunnel testing. The computational fluid dynamics and wind tunnel results are compared for validation. Furthermore, an unmanned air vehicle model was designed and manufactured to prove that the propulsive wing concept is flyable. The article shows that the aerodynamic forces developed on the cross-flow fan airfoil are not only functions of Reynolds number and angle of attack as for standard airfoils but also function of the fan rotational speed. The results show the great effect of the rotational speed of fan on lift augmentation and thrust generation through the high momentum flow getting out of the fan nozzle. Wind tunnel tests show that the suction effect of the fan provides stall free operation up to very high angles of attack (40 degrees) leading to unprecedented values of lift coefficient up to 5.8. The flight test conducted showed the great potential of the new aircraft to perform the expected low cruise speed and high angles of attack flight.

APA, Harvard, Vancouver, ISO, and other styles

48

Saeed, B., G. Gratton, and C. Mares. "A feasibility assessment of annular winged VTOL flight vehicles." Aeronautical Journal 115, no. 1173 (November 2011): 683–92. http://dx.doi.org/10.1017/s0001924000006400.

Full text

Abstract:

AbstractThis paper presents a feasibility study to integrate a developed lift system (an annular wing wrapped around a centrifugal flow generator) into a Vertical/Short Take-Off and Landing V/STOL aircraft. Different physical scales, from micro aerial vehicle to a Harrier Jump Jet scale, for a variety of propulsion systems are explored. The system has shown to be viable for several classes of aircraft but with better performance offered by a micro-aerial-vehicle (~40g) and a large vehicle (~10,000kg) with a turbofan engine, albeit in both cases with apparently worse performance than is offered by current technologies. The wingform does not appear to be feasible in the light aircraft scale whilst using internal combustion engines.

APA, Harvard, Vancouver, ISO, and other styles

49

Zhu, Bing-Jie, Zhong-Xi Hou, and Hua-Jiang Ouyang. "Trajectory optimization of unmanned aerial vehicle in dynamic soaring." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 231, no. 10 (August 28, 2016): 1779–93. http://dx.doi.org/10.1177/0954410016664912.

Full text

Abstract:

An aircraft can extract energy from a gradient wind field by dynamic soaring. The paper presents trajectory optimization of an unmanned aerial vehicle for dynamic soaring by numerical analysis and validates the theoretical work through flight test. The collocation approach is used to convert the trajectory optimization problem into parameters optimization. The control and state parameters include lift coefficient, bank angle, positions, flight path angle, heading angle, and airspeed, which are obtained from the parameter optimization software. To validate the results of numerical simulation, the dynamic soaring experiment is also performed and experimental data are analyzed. This research work shows that the unmanned aerial vehicle can gain enough flight energy from the gradient wind field by following an optimal dynamic soaring trajectory. Meanwhile, the variation of flight path angle, heading angle, and airspeed has a significant influence on the energy transform. The solution can provide theoretical guide to unmanned aerial vehicles for extracting maximum energy from gradient wind fields.

APA, Harvard, Vancouver, ISO, and other styles

50

Honcharov, Yevhen, Nataliia Kriukova, Sofia Vietvytska, Vladyslav Markov, and Ihor Poliakov. "DEVELOPMENT, DESIGN AND APPLICATION OF UNMANNED AERIAL VEHICLES FOR POWER LINES." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 2(8) (June 15, 2021): 15–20. http://dx.doi.org/10.20998/2413-4295.2021.02.03.

Full text

Abstract:

The article reviews the methods for improving the technology of monitoring and inspection of the state of power grids. The state of development in the design and methods of using unmanned aerial vehicles, which are intended for servicing power lines, is analyzed. A number of issues related to the concept of unmanned aerial vehicles with high lifting capacity are considered, which allows them to be used for various means of maintenance of power lines, which in turn reduces capital costs. Unmanned aerial vehicles are increasingly being used by utilities, which reduces the risks and costs of maintenance compared to other transmission line monitoring systems. It was determined that in the field of electric power industry the most promising of the methods for monitoring power lines is the application of unmanned aerial vehicles together with the use of modern measuring equipment and digital technologies. It is concluded that a significant advantage of the use of unmanned aerial vehicles is their possibility, which reduces costs and increases the efficiency of their use as a means of determining promising locations for wind farms. It is noted that with the transition of the global electricity industry to the use of unmanned aerial vehicles will save resources and reduce costs. Moreover, it is determined that the use of unmanned aerial vehicles with high lifting capacity allows minimizing the cost of using additional lifting equipment and technical personnel. In particular, high-lift unmanned aerial vehicles using flamethrowers can effectively remove obstacles such as clogging on power lines. It is noted that the use of unmanned aerial vehicles will increase the safety of employees in the maintenance of power facilities and power lines. The obtained results from the analysis of the technical condition of the use of unmanned aerial vehicles indicate the prospects for the introduction of remote control systems and monitoring of the operational condition of power lines.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Aerial lifts'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles