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Viewing 1 to 30 of 120
2017-10-08
Technical Paper
2017-01-2408
Lei Zhou, Hongxing Zhang, Zhenfeng Zhao, Fujun Zhang
The Opposed Piston Two-Stroke (OPTS) engine has several advantages for power density, fuel tolerance, fuel efficiency and package space. A new type of balanced opposed-piston folded-crank train two-stroke engine for Unmanned Aerial Vehicle (UAV) was studied in this paper. The effects of high altitude environment on engine performance and emissions are investigated by thermodynamic simulation. Moreover, the matching between the engine and turbocharger was designed and optimized for different altitude levels. The results indicate that a suitable turbocharger for OPTS engine can achieve the purpose of improving the quality of scavenging, lowering the fuel consumption and recovering power at high altitude environment. Finally, an optimized OPTS engine model especially for UAV is proposed in this research.
2017-09-19
Technical Paper
2017-01-2064
Parvez Alam M, Dinesh Manoharan, Satheesh Chandramohan, Sabarish Chakkath, Sunil MAURYA
In the present market, multiple sophisticate and expensive Thrust Test Rigs for Brushless Motors (BLDC Motor) are available making it impossible to conduct such thrust analysis on a regular and cost effective basis. Moreover the present test rigs are incapable to measure high Thrust values. This needs specialized thrust testing rig which is more expensive. This paper aims at Design & Development of the Small Scale Test Rig Setup for measurement of the thrust of any Brushless DC motor and helps in refining the Selection of motor and propeller. This is a set up based on cost efficiency factor to implement such rigs, test and for comparing the static thrust produced by the BLDC motor. The fairly simple construction contains a weighing machine, a Tachometer and a Wattmeter to measure the Thrust, RPM and the Current Drawn respectively, and provide comprehensive, accurate and efficient data coming from the BLDC Motor including the Propeller and Electronic Speed Control (ESC).
2017-09-19
Technical Paper
2017-01-2063
Patrick Browning, Bryan Shambaugh, Joseph Dygert
The dielectric barrier discharge (DBD) has been studied significantly in the past 2 decades for its applications to various aerodynamic problems. The most common aerodynamic applications have been stall/separation control and boundary layer modification. Recently several researchers have proposed utilizing the DBD in various configurations to act as viable propulsion systems for micro and nano aerial vehicles. The DBD produces stable atmospheric-pressure non-thermal plasma in a thin sheet with a preferred direction of flow. The plasma flow, driven by electrohydrodynamic body forces, entrains the quiescent air around it and thus develops into a low speed jet on the order of 10-1 to 101 m/s. Several researchers have utilized DBDs in an annular geometric setup as a propulsion device. Other researchers have used them to alter rectangular duct flows and directional jet devices. This study investigates 2-D duct flows for applications in micro plasma thrusters.
2017-09-19
Technical Paper
2017-01-2070
Nicholas Anderson, Joseph Gao, Eric Whitman, Srikanth Gururajan
Recent advances in Small Unmanned Aerial Systems (SUAS) or drone technologies has resulted in their widespread use in a number of civilian applications, such as aerial imaging, infrastructure inspection, precision agriculture, among others. While this technology is accessible for everyone, it still requires a highly skilled operator to be able to successfully operate these drones in a safe and efficient manner. At the same time, the developments in Virtual/Augmented Reality (V/AR) technologies present opportunities for combining the two into novel applications and use cases, while providing an intuitive interface for interacting with the drones – this opens up possibilities for effective use of the drones by relatively untrained operators for civilian and military use.
2017-09-19
Technical Paper
2017-01-2062
Tushar Choudhary, Mithilesh Sahu, Shreya KRISHNA
Solid oxide fuel cell (SOFC) is the most promising candidate for utilization of waste generated from the GT based power system. By coupling SOFC with gas turbine (GT) based power system, a hybrid SOFC–GT power system has been developed and the thermal efficiency of the system can be enhanced upto 70-85%. This paper focuses of thermodynamic analysis of an internal reformed solid oxide fuel cell which is integrated with the gas turbine cycle to form a hybrid power generation system for an unmanned aerial vehicle (UAV) with a long range. Thermodynamic 1st and 2nd law, parametric analysis has been carried out and the effect of various parameters such as compressor pressure ratio, turbine inlet temperature, air flow rate has been examined. In order to validate the results, present work has been compared with the available literature and it shows good agreement.
2017-09-19
Technical Paper
2017-01-2059
Enrico Cestino, Giacomo Frulla, Renzo Duella, Paolo Piana, Francesco Pennella, Francesco Danzi
Future generations of civil aircrafts and unconventional unmanned configurations demand for innovative structural concepts to obtain the structural performance, and thus reduce the structural weight. For instance, one of the method to improve structural component is the material coupling used to alter static and dynamic aeroelastic stabilities. It is therefore useful to use an accurate and computationally efficient beam model during the preliminary design phase. In the present work, a numerical validation of equivalent homogeneous orthotropic material procedure, described in [1] and [2], is performed by the application of structural topology optimization technique [3] on a box beam made of isotropic material. The overall equivalent bending, torsional and coupled stiffness is derived by means of homogenization of the shell skin and of the stiffener plate stiffness. The optimum theoretical conditions of bending-torsion coupling was obtained when stiffeners were oriented at about 27°.
2017-09-19
Technical Paper
2017-01-2065
Sebastian Bandycki, Michele Trancossi, Jose Pascoa
This paper presents a comparison between different hypotheses of propulsion of a spherical UAS. Different architectures have been analyzed assessing their specific aerodynamic, energetic, and flight mechanics features. The comparison has been performed assuming the robustness of flight control in different wind conditions, defining for each the specific operative ranges, mission profiles, and energy assessment. An effective energy assessment and comparison against a commercial UAS has been produced. Even if the paper considers a preliminary simplified configuration, it demonstrates clearly to be competitive against traditional quadcopters in a predefined reference mission.
2017-08-01
Journal Article
2017-01-9283
Peter R. Hooper
Abstract This paper reports on the research and development challenges experienced from dynamometer testing of a spark ignition UAV engine operating on heavy fuel. The engine is a segregated scavenging two stroke engine with air charge delivery by means of integral stepped pistons overcoming durability issues of conventional crankcase scavenged engines. A key element of the experimental study builds upon performance development to address the need for repeatable cold start on low volatility fuel thereby eliminating gasoline from UAV theatres of deployment. Lubrication challenges normally associated with crankcase scavenged two stroke engines are avoided by the integrated re-circulatory lubrication system. The fuel explored in this study is kerosene JET A-1.
2017-07-10
Technical Paper
2017-28-1949
Johnson Jose, Ramesh M, G Venkatesan, M Khader Basha
Abstract Unmanned Aerial Vehicles (UAV) are being deployed in military, law enforcement, search & rescue, scientific research, environmental & climate studies, reconnaissance and other commercial and non-commercial applications on a large scale. A design and development of landing gear system has been taken up for a UAV. This paper presents the design optimization of structural components of Wheel-Brake & Fork assembly pertaining to the Main Landing Gear (MLG) for a UAV. The wheel, fork, axle and brake unit constitute the wheel assembly. The wheel-brake assembly is assembled with the strut assembly and forms the Landing gear system. The Fork is the connecting member between the shock strut and the axle containing the wheel-brake assembly. As the fork and axle are subjected to shock loads while landing, the strength of these components are very much essential to withstand the dynamic loads.
2017-06-29
Journal Article
2017-01-9000
Teresa Donateo, Antonio Ficarella
Abstract The design of a hybrid electric powertrain requires a complex optimization procedure because its performance will strongly depend on both the size of the components and the energy management strategy. The problem is particular critical in the aircraft field because of the strong constraints to be fulfilled (in particular in terms of weight and volume). The problem was addressed in the present investigation by linking an in-house simulation code for hybrid electric aircraft with a commercial many-objective optimization software. The design variables include the size of engine and electric motor, the specification of the battery (typology, nominal capacity, bus voltage), the cooling method of the motor and the battery management strategy. Several key performance indexes were suggested by the industrial partner. The four most important indexes were used as fitness functions: electric endurance, fuel consumption, take-off distance and powertrain volume.
2017-03-14
Journal Article
2017-01-9276
Joseph K. Ausserer, Marc D. Polanka, Jacob A. Baranski, Keith D. Grinstead, Paul J. Litke
Abstract The rapid expansion of the market for remotely piloted aircraft (RPA) includes a particular interest in 10-25 kg vehicles for monitoring, surveillance, and reconnaissance. Power-plant options for these aircraft are often 10-100 cm3 internal combustion engines. Both power and fuel conversion efficiency decrease with increasing rapidity in the aforementioned size range. Fuel conversion efficiency decreases from ∼30% for conventional-scale engines (>100 cm3 displacement) to <5% for micro glow-fuel engines (<10 cm3 displacement), while brake mean effective pressure decreases from >10 bar (>100 cm3) to <4 bar (<10 cm3). Based on research documented in the literature, the losses responsible for the increase in the rate of decreasing performance cannot be clearly defined.
2017-01-10
Technical Paper
2017-26-0336
Ganesh Liladhar Yewale, Abhishek Tapkire, D Radhakrishna, Popat Shejwal, Kaushal Singh, Gaurav Panchal
Abstract VRDE has developed Wankel type rotary engine to achieve high power output & fuel efficiency for indigenization programme of UAVs. This engine is meeting all performance parameters needed for intended aerial vehicle. This paper describes the testing methodology followed by development engineers to prove the endurance and reliability of UAV engine for airworthiness certification. This paper gives the brief about testing carried out on the Wankel engine, failures faced during endurance testing and their rectification to enhance the life of the engine to achieve hundred test cycle mark. This paper also briefs about the test set up, endurance test cycles simulating the practical operating conditions.
2016-11-08
Technical Paper
2016-32-0045
Joseph K. Ausserer, Marc D. Polanka, Jacob Baranski, Paul Litke
Abstract Small remotely piloted aircraft (10-25 kg) powered by internal combustion engines typically operate on motor gasoline, which has an anti-knock index (AKI) of >80. To comply with the single-battlefield-fuel initiative in DoD Directive 4140.25, interest has been increasing in converting the 1-10 kW power plants in the aforementioned size class to run on lower AKI fuels such as diesel and JP-8, which have AKIs of ∼20. It has been speculated that the higher losses (short circuiting, incomplete combustion, heat transfer) that cause these engines to have lower efficiencies than their conventional-scale counterparts may also relax the fuel-AKI requirements of the engines. To investigate that idea, the fuel-AKI requirement of a 3W-55i engine was mapped and compared to that of the engine on the manufacturer-recommended 98 (octane number) ON fuel.
2016-11-08
Technical Paper
2016-32-0078
Mark R. Mataczynski, Paul Litke, Benjamin Naguy, Jacob Baranski
Abstract Aircraft engine power is degraded with increasing altitude according to the resultant reduction in air pressure, temperature, and density. One way to mitigate this problem is through turbo-normalization of the air being supplied to the engine. Supercharger and turbocharger components suffer from a well-recognized loss in efficiency as they are scaled down in order to match the reduced mass flow demands of small-scale Internal Combustion Engines. This is due in large part to problems related to machining tolerance limitations, such as the increase in relative operating clearances, and increased blade thickness relative to the flow area. As Internal Combustion Engines decrease in size, they also suffer from efficiency losses owing primarily to thermal loss. This amplifies the importance of maximizing the efficiency of all sub-systems in order to minimize specific fuel consumption and enhance overall aircraft performance.
2016-10-25
Technical Paper
2016-36-0437
Gustavo de Carvalho Bertoli, Geraldo José Adabo, Gefeson Mendes Pacheco
Abstract A method for conceptual design of Solar Powered Unmanned Aircraft System (UAS) is presented. This method is based on traditional design methodology - wing loading estimation for preliminary sizing - modified for Solar Powered UAS case. Based on past works on Solar Powered UAS design, proposes a method that considers payload power consumption and therefore its impact on battery sizing. This battery sizing composes vehicle conceptual sizing equation. This method is useful for an assessment of Solar Powered UAS use in specific missions and serving as a start point for a more detailed design. A user interface was developed to automate the design process based on this method proposed.
2016-09-20
Technical Paper
2016-01-1980
Syama M. Rao, Dineshkumar M
Abstract This paper studies admissible state trajectories for an unmanned aerial vehicle(UAV) by performing dynamic soaring technique in the wind gradient. An optimization problem is formulated by employing direct optimal piece wise control. A 3-DOF point mass model system dynamics of UAV is considered. The bank angle and lift co-efficient are identified as control variables. A UAV of mass 5.44kg is considered for this study. Performance measures considered are maximization of specific energy and maximization of specific energy rate extracted by the vehicle, and minimization of the control effort. The effects of linear and parabolic wind gradient on maximizing the specific energy of an autonomous dynamic soaring UAV is also studied and minimum linear gradient required is found. The loop radius of the loiter pattern is maximized for applications like surveillance and patrolling of a localized area along with energy maximization as objective function.
2016-09-20
Technical Paper
2016-01-2004
M. Parvez Alam, Dinesh Manoharan
In this paper we discuss about the design and development of an “Autonomous Amphibious Unmanned Aerial Vehicle (AAUAV)” that can fly autonomously to the polluted water areas where human accessibility is formidable to test the water quality. The AAUAV system is an integrated multi-copter with tilt rotor capability to facilitate easy landing, navigation and maneuver on water. A 3D CAD model has been designed and analyzed. A specific propulsion system has been devised and lab tested. A proof of concept model has been made and tested in the field with its instruments to ascertain its technical/ operational feasibility. This system can also be tailored to collect and store the water samples from the polluted sites for further comprehensive research at the laboratory. AAUAV system is the novel solution to the polluted environment through a complete integrated system. This will be an effective alternative for the conventional water sampling techniques.
2016-04-05
Technical Paper
2016-01-1467
Neal Carter, Alireza Hashemian, Nathan A. Rose, William T.C. Neale
Abstract Improvements in computer image processing and identification capability have led to programs that can rapidly perform calculations and model the three-dimensional spatial characteristics of objects simply from photographs or video frames. This process, known as structure-from-motion or image based scanning, is a photogrammetric technique that analyzes features of photographs or video frames from multiple angles to create dense surface models or point clouds. Concurrently, unmanned aircraft systems have gained widespread popularity due to their reliability, low-cost, and relative ease of use. These aircraft systems allow for the capture of video or still photographic footage of subjects from unique perspectives. This paper explores the efficacy of using a point cloud created from unmanned aerial vehicle video footage with traditional single-image photogrammetry methods to recreate physical evidence at a crash scene.
2015-09-22
Technical Paper
2015-36-0543
Rodolfo Antonio da Silva Araujo, José Antonio Rodrigues, Marcelo Lopes de Oliveira e Souza
Abstract The increasing development of Unmanned Aerial Vehicle (UAV) technologies has allowed greater use of UAVs as remote sensing platforms to enhance satellite and manned aerial vehicle remote sensing surveillance and environmental management systems. Particularly, the Brazilian National Institute for Space Research - INPE has an Environmental Data Collection System (SCD) since 1993. Recently, the MCTI (Ministry of Science, Technology and Innovation) opened the National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN). Both may need additional resources for their expansions in the near future as offered by UAV technologies. These needs illustrate the potential of UAV technologies as complement to existing or future systems. This paper presents an overview of data transmission used in UAVs for remote sensing surveillance and environmental management systems.
2015-09-22
Technical Paper
2015-36-0364
Everton Spuldaro, Justin Donoghue, Jacob Hough, Bruno Rocha
Abstract A long endurance high efficiency Unmanned Aerial Vehicle (UAV) is being developed by a group of researchers and students in the Mechanical Engineering Technology program at Algonquin College, Ottawa, ON, Canada. The design is based on a tailless, staggered tandem wing configuration, with a carbon fiber frame and electric propulsion. The developed aircraft has a maximum weight of 12.5 kg, well within the 25 kg limit outlined by Transport Canada for permission-free operation. The UAV was designed to fly missions exceeding 24 hours, performing surveillance and oil pipeline monitoring and inspection, either autonomously or under radio control from a ground station, with medium to high payload capacity. This paper describes the process of designing, manufacturing and testing the developed configuration. The operational requirements are delineated as conceptualized by the development team.
2015-09-15
Technical Paper
2015-01-2424
Alberto Boretti, Shuheng Jiang
Abstract Unmanned Aerial Vehicles (UAV) require simple and reliable engines of high power to weight ratio. Wankel and two stroke engines offer many advantages over four stroke engines. A two stroke engines featuring crank case scavenging, precise oiling, direct injection and jet ignition is analyzed here by using CAD, CFD and CAE tools. Results of simulations of engine performances are shown in details. The CFD analysis is used to study fuel injection, mixing and combustion. The CAE model then returns the engine performances over the full range of loads and speeds with the combustion parameters given as an input. The use of asymmetric rather than symmetric port timing and supercharging scavenging is finally suggested as the best avenue to further improve power density and fuel conversion efficiency.
2015-09-15
Technical Paper
2015-01-2455
Roshen Jay Jaswantlal, Piergiovanni Marzocca, Rafael Palacios
Abstract The implementation of Synthetic Jet Actuators (SJAs) on Unmanned Aerial Vehicles (UAVs) provides a safe test-bed for analysis of improved performance, in the hope of certification of this technology on commercial aircraft in the future. The use of high resolution numerical methods (i.e. CFD) to capture the details of the effects of SJAs on flows and on the hosting lifting surface are computationally expensive and time-consuming, which renders them ineffective for use in real-time flow control implementations. Suitable alternatives include the use of Reduced Order Models (ROMs) to capture the lower resolution overall effects of the jets on the flow and the hosting structure. This research paper analyses the effects of SJAs on aircraft wings using a ROM for the purpose of determining the unsteady aerodynamic forces modified by the presence of the SJAs. The model developed is a 3D unsteady panel code where the jets are represented by source panels.
2015-09-15
Technical Paper
2015-01-2456
Roberto Sabatini, Terry Moore, Chris Hill, Subramanian Ramasamy
Abstract Global Navigation Satellite Systems (GNSS) can support the development of low-cost and high performance navigation and guidance architectures for Unmanned Aircraft Systems (UAS) and, in conjunction with suitable data link technologies, the provision of Automated Dependent Surveillance (ADS) functionalities for cooperative Sense-and-Avoid (SAA). In non-cooperative SAA, the adoption of GNSS can also provide the key positioning and, in some cases, attitude data (using multiple antennas) required for automated collision avoidance. A key limitation of GNSS for both cooperative (ADS) and non-cooperative applications is represented by the achievable levels of integrity. Therefore, an Avionics Based Integrity Augmentation (ABIA) solution is proposed to support the development of an Integrity-Augmented SAA (IAS) architecture suitable for both cooperative and non-cooperative scenarios.
2015-09-15
Technical Paper
2015-01-2457
Jae Chung, Yushing Cheung
Abstract In this paper, we investigate the formation control of multiple unmanned aerial vehicles (UAVs) in an obstacle-laden environment for target tracking. The main contribution of this paper is to develop a potential field based leader-follower formation control method for target tracking and obstacle/collision avoidance. In the potential field, a quantity of virtual positive charge carried by each of UAVs varies depending upon their roles as a leader or follower when obstacles and targets are regarded as ions with larger positive and negative charges, respectively. Therefore, the formation formed by the UAVs connected with their inter-bonds could be adapted while the UAVs get around the obstacles and are attracted to the targets. The potential field based leader-follower formation control method is developed to reshape a UAV team configuration to track a target while the UAV team avoids the obstacles.
2015-09-15
Technical Paper
2015-01-2454
Patrick H. Browning, Wade Huebsch
Abstract The design and testing of small unmanned aerial vehicle (sUAV) prototypes can provide numerous difficulties when compared to the same process applied to larger aircraft. In most cases, it is desirable to have a better understanding of the low Reynolds number aerodynamics and stability characteristics prior to completion of the final sUAV design. This paper describes the design, construction, and operational performance of a pneumatic launch apparatus that has been used at West Virginia University (WVU) for the development and early flight testing of transforming sUAV platforms. Although other launch platforms exist that can provide the safe launch of such prototypes, the particular launch apparatus constructed at WVU exhibits unmatched launch efficiency, and is far less expensive to operate per shot than any other launch system available.
2015-09-15
Technical Paper
2015-01-2463
Giacomo Frulla, Enrico Cestino, Piero Gili, Michele Visone, Domenico Scozzola
Abstract The problem of wing shape modification under loads in order to enhance the aircraft performance and control is continuously improving by researchers. This requirement is in contrast to the airworthiness regulations that constraint stiffness and stress of the structure in order to maintain structural integrity under operative flight conditions. The lifting surface modification is more stringent in those cases, such as UAV configurations, where the installed power is limited but the variety of operative scenario is wider than in conventional aircraft. A possible solution for adaptive wing configuration can be found in the VENTURAS Project idea. The VENTURAS Project is a funded project with the aim of improve the wind turbine efficiency by means of introducing a twisting capability for the blade sections according to the best situation in any wind condition. The blade structure is composed by two parts: 1) internal supporting element, 2) external deformable envelope.
2015-09-15
Technical Paper
2015-01-2465
Michele Trancossi, Chris Bingham, Alfredo Capuani, Shyam Das, Antonio Dumas, Francesco Grimaccia, Mauro Madonia, Jose Pascoa, Tim Smith, Paul Stewart, Maharshi Subhash, Anna Sunol, Dean Vucinic
Abstract This paper presents a novel UAS (Unmanned Aerial System) designed for excellent low speed operations and VTOL performance. This aerial vehicle concept has been designed for maximizing the advantages by of the ACHEON (Aerial Coanda High Efficiency Orienting-jet Nozzle) propulsion system, which has been studied in a European commission under 7th framework programme. This UAS concept has been named MURALS (acronym of Multifunctional Unmanned Reconnaissance Aircraft for Low-speed and STOL operation). It has been studied as a joint activity of the members of the project as an evolution of a former concept, which has been developed during 80s and 90s by Aeritalia and Capuani. It has been adapted to host an ACHEON based propulsion system. In a first embodiment, the aircraft according to the invention has a not conventional shape with a single fuselage and its primary objective is to minimize the variation of the pitching moment allowing low speed operations.
2015-09-15
Technical Paper
2015-01-2459
Francesco Cappello, Subramanian Ramasamy, Roberto Sabatini
Abstract Multi-Sensor Data Fusion (MSDF) techniques involving satellite and inertial-based sensors are widely adopted to improve the navigation solution of a number of mission- and safety-critical tasks. Such integrated Navigation and Guidance Systems (NGS) currently do not meet the required level of performance in all flight phases of small Remotely Piloted Aircraft Systems (RPAS). In this paper an innovative Square Root-Unscented Kalman Filter (SR-UKF) based NGS is presented and compared with a conventional UKF governed design. The presented system architectures adopt state-of-the-art information fusion approach based on a number of low-cost sensors including; Global Navigation Satellite Systems (GNSS), Micro-Electro-Mechanical System (MEMS) based Inertial Measurement Unit (IMU) and Vision Based Navigation (VBN) sensors.
2015-09-15
Technical Paper
2015-01-2461
Enrico Troiani, Maria Pia Falaschetti, Sara Taddia, Alessandro Ceruti
Abstract The high number of hull losses is a main concern in the UAV field, mostly due to the high cost of on-board equipment. A crashworthiness design can be helpful to control the extent and position of crash impact damage, minimizing equipment losses. However, the wide use of composite materials has recently put the accent on the lack of data about the behavior of these structures under operative loads, such as the crash conditions. This paper presents the outcome of a set of tests carried out to achieve a controlled crush of UAV structures, and to maximize the Specific Energy Absorption. In this work, a small-scale experimental test able to characterize the energy absorption of a Carbon-fiber-reinforced polymer under compression was developed introducing self-supporting sinusoidal shape specimens, which avoid the need for complex anti-buckling devices.
2015-09-15
Technical Paper
2015-01-2460
Melissa Arras, Giuliano Coppotelli, Piergiovanni Marzocca, Antonio Simone Mezzapesa
Abstract In this paper the finite element model of an Unmanned Aerial Vehicle is updated by using experimental data coming from a standard ground vibration test in order to improve the numerical-experimental correlation. A sensitivity-based updating methodology that iteratively minimizes a residual vector, defined on the modal parameters (e.g. natural frequencies and mode shapes), is considered to identify the unknown values of the updating parameters. The structure under investigation is the Clarkson University Golden Eagle UAV. An initial numerical model of the structure is obtained by assembling the individual components previously updated which included wings, fuselage, horizontal tail, vertical tails and tail booms. As a result the identification procedure shifts its focus on the joints between UAV elements which could not be modeled accurately in earlier investigations.
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