scholarly journals Simulation and Test of Discrete Mobile Surfaces for a RC-Aircraft

Aerospace ◽  
2019 ◽  
Vol 6 (11) ◽  
pp. 122
Author(s):  
Francesco Nicassio ◽  
Gennaro Scarselli
Keyword(s):  
Composite Materials ◽  
Unmanned Aerial Vehicles ◽  
Composite Plate ◽  
Stacking Sequence ◽  
Total Thickness ◽  
Aerodynamic Efficiency ◽  
Aerodynamic Pressure ◽  
Aerial Vehicles ◽  
Discrete Surface ◽  
Lever Effect

Morphing structures suitable for unmanned aerial vehicles (UAVs) have been investigated for several years. This paper presents a novel lightweight, morphing concept based on the exploitation of the “lever effect” of a bistable composite plate that can be integrated in an UAV horizontal tail. Flight dynamics equations are solved in Simulink environment, thus being able to simulate and compare different flight conditions with conventional and bistable command surfaces. Subsequently, bistable plates are built by using composite materials, paying particular attention to dimensions, asymmetric stacking sequence and total thickness needed to achieve bistability. NACA0011 airfoil is chosen for proving this concept. Wind tunnel tests demonstrate that the discrete surface is capable of withstanding the aerodynamic pressure. A remotely piloted vehicle is employed to test the discrete horizontal tail command during the take-off. The results show that, choosing a proper configuration of constraints, stacking sequence and aspect ratio for the bistable laminate, it is possible to tailor the snap-through mechanism. The proposed concept appears lighter and increases aerodynamic efficiency when compared to conventional UAV command surfaces.

scholarly journals Application and evaluation of the technical condition of composite materials in aircraft and unmanned aerial vehicles by acoustic emission method of nondestructive testing

2022 ◽  
Vol 21 (4) ◽  
pp. 328-336
Author(s):  
A. V. Popov ◽  
A. O. Samuylov ◽  
I. S. Cherepanov
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Nondestructive Testing ◽  
Unmanned Aerial Vehicles ◽  
Technical Condition ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Software Complex ◽  
Aerial Vehicles ◽  
Aerial Vehicle

Introduction. The paper analyzes the application of composite materials as the main determining method of reducing the mass of the airframe and an unmanned aerial vehicle. Advanced nondestructive testing methods provide assessing the technical condition of these materials, as well as determining stress concentrators on the airframe and an unmanned aerial vehicle with high accuracy in order to make a decision on the further operation of this object under control. The objective of the work was to increase the accuracy and efficiency of the assessment of crack resistance of composite materials through the acoustic emission control.Materials and Methods. This paper presents the nomenclature of composite materials used in the construction of various aircraft, including unmanned aerial vehicles. The most possible probable defects of these materials due to the influence of operational factors are presented. The applied methods of nondestructive testing of composite material and selection of the most suitable one according to specific advantages were compared. An experiment was carried out to determine the strength limits of carbon fiber using a hardware and software complex by acoustic emission method. The research results are presented in the form of drawings projected by the hardware and software complex.Results. The application of the acoustic-emission method of composite material control is described.Discussion and Conclusions. The results obtained experimentally can be used in the process of determining the strength limits of various composite materials by the acoustic emission method of nondestructive testing to assess the technical condition in mechanical engineering, shipbuilding, and aircraft construction. The paper is recommended to researchers involved in the design of aircraft and unmanned aerial vehicles.

Viability of joined flight for small unmanned aerial vehicles

2019 ◽  
Vol 124 (1273) ◽  
pp. 297-322
Author(s):  
E. Levis ◽  
F. Pleho ◽  
J. Hedges
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Parametric Analysis ◽  
Aircraft Design ◽  
Relative Magnitude ◽  
Design Parameters ◽  
Wing Loading ◽  
Aerodynamic Efficiency ◽  
Aspect Ratios ◽  
Aerial Vehicles ◽  
Better Than

ABSTRACTThe range of small, electrically powered UAVs is still limited by the mass specific energy of batteries. This paper investigates the idea that, in cases where multiple aircraft must transit to the same location, savings in mass or an extension of achievable range are possible when they join wingtip-to-wingtip. The viability of joined flight is investigated by quantifying the relative magnitude of savings resulting from increased aerodynamic efficiency and that of penalties due to the increased structural and component weights. Through a parametric analysis the level of savings achievable is found to be greatly dependent on the proportion of the flight spent in a joined configuration and aircraft design parameters such as wing loading, aspect ratio and the added weight of the joining mechanism. A custom, multidisciplinary UAV sizing algorithm is presented and utilised to design several sample aircraft, featuring two different joining mechanism architectures. The results verify the findings of the parametric study and indicate that mass savings are possible only for moderate to low aspect ratios, with semi-permanent magnetic joining mechanism performing better than rigid structural ones, even when the joined fight segment accounts for only 30% of the total airborne time.

scholarly journals Aerodynamic efficiency and performance enhancement of fixed-wing unmanned aerial vehicles using novel configurations and techniques

2018 ◽  
Author(s):  
Περικλής Παναγιώτου
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Performance Enhancement ◽  
Operating Conditions ◽  
Aerodynamic Efficiency ◽  
Aerial Vehicles ◽  
And Performance

Ο σκοπός της διδακτορικής διατριβής είναι η βελτιστοποίηση της αεροδυναμικής απόδοσης και των επιδόσεων Μη-Επανδρωμένων Αεροχημάτων (ΜΕΑ) σταθερής πτέρυγας, μεγάλης αυτονομίας και μέσου ύψους (MALE UAV ή tactical UAV – NATO classification), που επιχειρούν σε συνθήκες πτήσης με Mach < 0.3. Πρόκειται για μια πλήρη τεχνολογική έρευνα, τα βασικά αντικείμενα της οποίας είναι α) η διερεύνηση της ροής γύρω από ΜΕΑ σταθερής πτέρυγας, β) η ανάλυση του ισοζυγίου οπισθέλκουσας δύναμης και εντοπισμός των κύριων πηγών αυτής, γ) η αναζήτηση, καταγραφή, και αξιολόγηση πιθανών τεχνολογιών, γεωμετριών, και τεχνικών για τη βελτίωση της αεροδυναμικής απόδοσης και των επιδόσεων ΜΕΑ (technology screening), δ) η επιλογή και λεπτομερής διερεύνηση των γεωμετριών που δυνητικά προσφέρουν τα περισσότερα πλεονεκτήματα, και ε) η εφαρμογή των παραπάνω σε εφαρμοσμένες μελέτες σχεδιασμού ΜΕΑ για αξιολόγηση και εκτίμηση επιδόσεων. Σε αντίθεση με τις υπάρχουσα βιβλιογραφία, η παρούσα έρευνα προσεγγίζει ολιστικά τον σχεδιασμό και την βελτιστοποίηση των ΜΕΑ σταθερής πτέρυγας, εκκινώντας από θεμελιώδεις ρευστοδυναμικές αναλύσεις, συνεχίζοντας με παραμετρικές αναλύσεις αεροδυναμικής, και κλείνοντας με εφαρμογή σε ολοκληρωμένες μελέτες σχεδιασμού. Για αυτό το σκοπό χρησιμοποιείται μια πληθώρα εργαλείων, που περιλαμβάνουν λογισμικά υπολογιστικής μοντελοποίησης, πειραματικές διατάξεις και τεχνικές, καθώς επίσης και αναλυτικά εργαλεία διαστασιολόγησης, και υπολογισμού παραμέτρων αεροδυναμικής, ευστάθειας και επιδόσεων αεροχημάτων, που αναπτύχθηκαν στα πλαίσια της διατριβής (in-house tools). Αρχικά καθορίζεται και σχεδιάζεται μια γεωμετρία αναφοράς ΜΕΑ, της οποίας οι προδιαγραφές (requirements) και οι επιχειρησιακές συνθήκες (operating conditions) ορίζονται επίσης ως σημεία αναφοράς. Η ροή γύρω από το ΜΕΑ αναλύεται χρησιμοποιώντας τα εργαλεία αεροδυναμικής ανάλυσης και πραγματοποιείται μια ταξινόμηση της οπισθέλκουσας δύναμης (drag bookkeeping), τόσο για την κύρια πτέρυγα, όσο και για την συνολική γεωμετρία του ΜΕΑ. Στη συνέχεια, ερευνάται μια πληθώρα πιθανών επιλογών, τεχνολογιών, τεχνικών και γεωμετριών, που δυνητικά μπορεί να βελτιώσουν την επίδοση των ΜΕΑ σταθερής πτέρυγας. Δύο είδη γεωμετριών επιλέγονται τελικά για ενδελεχή μελέτη και περεταίρω ανάλυση, και συγκεκριμένα, τα winglets και τα σώματα BWB. Οι γεωμετρίες αυτές αναλύονται διεξοδικά σε υπολογιστικό, πειραματικό, και σχεδιαστικό επίπεδο. Όπως πιστοποιείται και από τις σχετικές επιστημονικές δημοσιεύσεις, η έρευνα οδηγεί σε πρωτότυπα συμπεράσματα και παρατηρήσεις που αφορούν τα ροϊκά φαινόμενα, και σε ανάπτυξη εξειδικευμένων μεθοδολογιών σχεδιασμού για εφαρμογές ΜΕΑ σταθερής πτέρυγας. Γίνεται επίσης και αποτίμηση των πλεονεκτημάτων της χρήσης των γεωμετριών αυτών, με τα αποτελέσματα να δείχνουν βελτίωση της τάξεως του 10% και 30% για τα winglets και τις πλατφόρμες BWB αντίστοιχα, όσον αφορά την αεροδυναμική απόδοση. Συνοψίζοντας, η διατριβή επικεντρώνεται στα ΜΕΑ τύπου MALE/tactical, λόγω του ότι αποτελούν το μεγαλύτερο κομμάτι της αγοράς των ΜΕΑ. Ωστόσο, με την προϋπόθεση ότι οι λόγοι ροϊκής ομοιότητας και οι επιχειρησιακές συνθήκες είναι πανομοιότυπες, οι προτεινόμενες μέθοδοι και τα επαγόμενα συμπεράσματα μπορούν να επεκταθούν και σε οποιοδήποτε άλλο αερόχημα σταθερής πτέρυγας, από ΜΕΑ μεγαλύτερης κλίμακας, μέχρι υπερ-ελαφρά ή ελαφρά αεροχήματα και μεταγωγικά αεροσκάφη. Επιπρόσθετα, η έρευνα που αφορά είτε σε στοιχειώδη ρευστοδυναμικά φαινόμενα, όπως είναι οι δίνες ακροπτερυγίου, είτε στις βελτιωτικές διατάξεις (winglets, BWB) έχει προεκτάσεις και σε άλλες εφαρμογές μεγαλύτερης κλίμακας, που αφορούν την κοινωνία και την βιομηχανία, όπως είναι για παράδειγμα τα επιβατηγά αεροσκάφη και οι εναέριες μεταφορές.

Análisis Y Diseño De Una Aeronave No Tripulada Para Uso Agrícola

2017 ◽  
Vol 13 (6) ◽  
pp. 135
Author(s):  
Javier Enrique Orna Chávez ◽  
Otto Fernando Balseca Sampedro ◽  
Jorge Isaías Caicedo Reyes ◽  
Diego Fernando Mayorga Pérez ◽  
Edwin Fernando Viteri Núñez ◽  
...  
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Unmanned Aerial Vehicles ◽  
Power Supply ◽  
Agricultural Sector ◽  
Flight Time ◽  
Unmanned Aircraft ◽  
Commercial Application ◽  
Autonomous Flight ◽  
Aerial Vehicles

The present research proposes to diversify the use of unmanned aerial vehicles (UAV) with rotating wings for applications in the agricultural sector. For this we have analyzed and designed an unmanned aircraft. In first instance the applications of this type of aircraft in this sector were reviewed to determine possible design conditions that would aid in the sizing and design of the aircraft. Once the requirements had been determined, aerodynamic analysis was carried out to size up and launch the required power output for the craft. This in order to optimize the weight and autonomous fight time to finally design an aircraft prototype built in carbon fiber with the aid of fault theories as applied to composite materials. At the end of the research, an unmanned aircraft of 6 rotors, each with an installed power supply of 700W was designed. The aircraft has an autonomous flight time of 40 minutes without a payload, 20 minutes with a payload of 3Kg, and 8 minutes with a payload of 5Kg. The commercial application of these aircraft are the monitoring of land and fumigation in inaccessible areas.

scholarly journals Aerodynamic Performance of an Octorotor SUAV with Different Rotor Spacing in Hover

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1364
Author(s):  
Yao Lei ◽  
Yuhui Huang ◽  
Hengda Wang
Keyword(s):  
Flow Field ◽  
Unmanned Aerial Vehicles ◽  
Aerodynamic Performance ◽  
Aerodynamic Efficiency ◽  
Experimental Platform ◽  
Vorticity Distribution ◽  
Aerial Vehicles ◽  
Spacing Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

To study the aerodynamic performance of hovering octorotor small unmanned aerial vehicles (SUAV) with different rotor spacing, the computational fluid dynamics (CFD) method is applied to analyze the flow field of an octorotor SUAV in detail. In addition, an experimental platform is built to measure the thrust and power of the rotors with rotor spacing ratios L/D of 1.0, 1.2, 1.4, 1.6, and 1.8, sequentially. According to the theory of momentum, rotor aerodynamic performance is obtained with qualitative analysis. Further analysis with numerical simulation is presented with the flow field of the octorotor SUAV, the vorticity distribution, velocity distribution, pressure distribution, and streamline. The results show that the aerodynamic performance varies with the rotor spacing. Specifically, the aerodynamic performance is poor at L/D = 1.0, which is accompanied with strong interaction of wake and tip vortexes and interaction with each other. However, the aerodynamic efficiency is much improved with a larger rotor spacing, especially achieving the highest at L/D = 1.8, which is considered to be the best rotor spacing ratio for this kind of octorotor SUAV.

scholarly journals Synthesis and Characterization of Composite Materials with Enhanced Thermo-Mechanical Properties for Unmanned Aerial Vehicles (Uavs) and Aerospace Technologies

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Zahid Iqbal Khan ◽  
Zurina Mohamad ◽  
Abdul Razak Rahmat ◽  
Unsia Habib
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Carbon Fibre ◽  
Unmanned Aerial Vehicles ◽  
Low Cost ◽  
Testing Machine ◽  
Carbon Composite ◽  
Scanning Calorimetry ◽  
Aerial Vehicles

Lightweight and high strength composite materials are vital for unmanned aerial vehicles (UAVs) and aerospace technologies with desired characteristics. Carbon composite materials exhibit extraordinary properties for UAVs and aerospace applications. This study aimed to discover the best-prepared composition of composites material having epoxy LY-5052 and carbon fibres laminate for UAVs. Besides, to develop a low cost with high specific strength composite material for aerospace application to replace metallic alloys. In this work, the vacuum bag technique is used to prepare rectangular strips of three different ratios of carbon fibre/epoxy laminates [(40:60), (50:50) and (60:40)] to obtain the best composite in terms of properties. The thermo-mechanical and viscoelastic behaviour of composite materials were evaluated using differential scanning calorimetry (DSC), universal testing machine (UTM) and dynamic mechanical analysis (DMA). The tensile strength of epoxy LY5052 composites with 60 wt% has enhanced to 986%, and glass transition temperature (Tg) was improved from 71oC to 110oC. Overall, 60 wt% carbon fibre exhibits better thermo-mechanical properties with lightweight, which may be a future composite material for aerospace, especially UAVs technologies.

scholarly journals Investigation of a Cruising Fixed Wing Mini Unmanned Aerial Vehicle Performance Optimization

2019 ◽  
Vol 4 (2) ◽  
pp. 280-293
Author(s):  
Shahrooz Eftekhari ◽  
Abdulkareem Sh. Mahdi Al-Obaidi
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Unmanned Aerial Vehicle ◽  
Performance Optimization ◽  
Experimental Validation ◽  
Vehicle Performance ◽  
Aerodynamic Efficiency ◽  
Aerial Vehicles ◽  
Military Applications ◽  
Aerial Vehicle ◽  
Wing Geometry

The applications of unmanned aerial vehicles have been extended through the recent decades and they are utilized for both civil and military applications. The urge to utilize unmanned aerial vehicles for civil purposes has elevated researchers and industries interest towards the mini unmanned aerial vehicle (MUAV) category due to its suitable configurations and capabilities for multidisciplinary civil purposes. This study is an effort to further enhance the aerodynamic efficiency of MUAVs through a parametric study of the wing and proposing an innovative bioinspired wing design. The research is conducted utilizing numerical simulation and experimental validation. This research provides a better understanding of different wing parameter(s) effect on the aerodynamic performance of the wing and mini unmanned aerial vehicles. A new wing configuration is designed, implemented and evaluated. The wing is named as Alpine since it is inspired by biomimicry of alpine swift bird. Evaluation of the new wing geometry shows that the Alpine wing geometry performs 35.9% more efficient compared to an existing wing with similar wing area. Hence, the aerodynamic efficiency optimization is achieved for the Alpine wing which helps to enhance the performance of MUAVs.

Development of thickened semi-synthetic engine oil M-5z / 20 AERO for four-stroke gasoline engines aircraft piston of unmanned aerial vehicles (UAVs)

2020 ◽  
Vol 06 ◽  
pp. 44-47
Author(s):  
A.A. Moykin ◽  
◽  
A.S. Medzhibovsky ◽  
S.A. Kriushin ◽  
M.V. Seleznev ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Engine Oil ◽  
Motor Oil ◽  
Gasoline Engines ◽  
State Research Institute ◽  
Technical Requirements ◽  
Aerial Vehicles ◽  
State Research ◽  
Industrial Batch ◽  
The Russian Federation

Nowadays, the creation of remotely-piloted aerial vehicles for various purposes is regarded as one of the most relevant and promising trends of aircraft development. FAU "25 State Research Institute of Chemmotology of the Ministry of Defense of the Russian Federation" have studied the operation features of aircraft piston engines and developed technical requirements for motor oil for piston four-stroke UAV engines, as well as a new engine oil M-5z/20 AERO in cooperation with NPP KVALITET, LLC. Based on the complex of qualification tests, the stated operational properties of the experimental-industrial batch of M-5z/20 AERO oil are generally confirmed.

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