FLEXIBLE MULTI-BODY DYNAMICS MODEL OF A BIO-INSPIRED ORNITHOPTER WITH EXPERIMENTAL VALIDATION

There is currently a large effort underway to understand the physics of avian-based flapping wing vehicles, known as ornithopters. There is a need for small aerial robots to conduct a variety of civilian and military missions. Efforts to model the flight physics of these vehicles have been complicated by a number of factors, including nonlinear elastic effects, multi-body characteristics, unsteady aerodynamics, and the strong coupling between fluid and structural dynamics. Experimental verification is crucial in order to achieve accurate simulation capabilities. A multi-disciplinary approach to modeling requires the use of tools representing individual disciplines, which must be combined to form a comprehensive model. In the framework of this research a five body flexible vehicle dynamics model and a novel experimental verification methodology is presented. For the model development and verification of the modeling assumptions, a data set providing refined wing kinematics of a test ornithopter research platform in free flight was used. Wing kinematics for the verification was obtained using a Vicon motion capture system. Lagrange equations of motion in terms of a generalized coordinate vector of the rigid and flexible bodies are formulated in order to model the flexible multi-body system. Model development and verification results are presented. The `luff region" and "thrust flap region" of the wing are modeled as flexible bodies. A floating reference frame formulation is used for the ornithopter. Flexible body constraints and modes are implemented using the Craig-Bampton method, which incorporates a semi-physical subspace method. A quasi-steady aerodynamic model using Blade Element Theory was correlated and verified for the problem using the experimental wing kinematics. The aerodynamic model was then formulated in terms of generalized coordinates of the five-body flexible multi-body system and is used in the resulting model in order to account for aero-elasticity. Modeling assumptions were verified and simulation results were compared with experimental free flight test data

Continuous Open Access Special Issue "Aircraft Design": Number 3/2021

Following the successful initial Special Issue on "Aircraft Design (SI-1/2017)" and the relaunch with "Aircraft Design (SI-2/2020)", this is already the third SI in sequence named "Aircraft Design (SI 3/2021)". Activities in the past showed that aircraft design may be a field too small to justify its own (subscription-based) journal. A continuous open access special issue may fill the gap. As such, the Special Issue "Aircraft Design" can be a home for all those working in the field who regret the absence of an aircraft design journal. SI-3/2021 contains six papers (original research articles) about 1.) Oil Fumes in the Cabin and Flight Safety, 2.) Closed-Loop Flying Quality Requirements, 3.) Preliminary Design of a Medium Range Box Wing Aircraft, 4.) Influence of Novel Airframe Technologies on the Feasibility of Fully-Electric Regional Aviation, 5.) Design and Optimization of a Large Turboprop Aircraft, 6.) Sources of Onboard Fumes and Smoke

Negotiating disciplinary boundaries in engineering problem-solving practice

Includes bibliographical referencesThe impetus for this research is the well-documented current inability of Higher Education to facilitate the level of problem solving required in 21st century engineering practice. The research contends that there is insufficient understanding of the nature of and relationship between the significantly different forms of disciplinary knowledge underpinning engineering practice. Situated in the Sociology of Education, and drawing on the social realist concepts of knowledge structures (Bernstein, 2000) and epistemic relations (Maton, 2014), the research maps the topology of engineering problem-solving practice in order to illuminate how novice problem solvers engage in epistemic code shifting in different industrial contexts. The aim in mapping problem-solving practices from an epistemological perspective is to make an empirical contribution to rethinking the theory/practice relationship in multidisciplinary engineering curricula and pedagogy, particularly at the level of technician. A novel and pragmatic problem-solving model - integrated from a range of disciplines - forms the organising framework for a methodologically pluralist case-study approach. The research design draws on a metaphor from the empirical site (modular automation systems) and sees the analysis of twelve matched cases in three categories. Case-study data consist of questionnaire texts, re-enactment interviews, expert verification interviews, and industry literature. The problem-solving model components (problem solver, problem environment, problem structure and problem-solving process) were analysed using, primarily, the Legitimation Code Theory concept of epistemic relations. This is a Cartesian plane-based instrument describing the nature of and relations between a phenomenon (what) and ways of approaching the phenomenon (how). Data analyses are presented as graphical relational maps of different practitioner knowledge practices in different contexts across three problem solving stages: approach, analysis and synthesis. Key findings demonstrate a symbiotic, structuring relationship between the 'what' and the 'how' of the problem in relation to the problem-solving components. Successful problem solving relies on the recognition of these relationships and the realisation of appropriate practice code conventions, as held to be legitimate both epistemologically and contextually. Successful practitioners engage in explicit code-shifting, generally drawing on a priori physics and mathematics-based knowledge, while acquiring a posteriori context-specific logic-based knowledge. High-achieving practitioners across these disciplinary domains demonstrate iterative code-shifting practices and discursive sensitivity. Recommendations for engineering education include the valuing of disciplinary differences and the acknowledgement of contextual complexity. It is suggested that the nature of engineering mathematics as currently taught and the role of mathematical thinking in enabling successful engineering problem-solving practice be investigated

Virtual Reality Games for Motor Rehabilitation

This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion

Optimization Framework for Crushing Plants

Optimization is a decision-making process to utilize available resources efficiently. The use of optimization methods provide opportunities for continuous improvements, increasing competitiveness, trade-off analysis and as a support tool for the decision-making process in industrial applications. One of such industrial applications where optimization methods are needed is coarse comminution and classification processes for aggregates and minerals processing industries. The coarse comminution and classification process, consisting of crushing and screening, is a heavy industrial process characterized by continuous operations. The processes handle large material volumes, are energy intensive, and suffer large variabilities during process operations. To understand the complexity and to replicate the process performance of the coarse comminution and classification processes, process simulation models have been under development for the past few decades. There are two types of process simulation models: steady-state simulation and dynamic simulation. The steady-state simulation models are based on instantaneous mass balancing while the dynamic simulation models are capable of capturing the process change over time due to non-ideal operating conditions. Both simulation types are capable of capturing the process performance, although the dynamic process simulations have been proven to have a higher fidelity for industrial applications. Both the steady-state and dynamic simulation models lack the capability of optimization methods which can potentially increase the utilization of the developed process simulation models. The optimization capabilities can further increase the functionality of the process simulation models and provide decision-making support. The thesis presents a modular optimization framework for carrying out process optimization and process improvements in a coarse comminution and classification process using process simulation models. The thesis describes the results of explorative studies carried out for developing the application of optimization methods and key performance indicators for the coarse comminution and classification process. The application of the optimization methods can generate new insights about the process performance with respect to the operating parameters, and non-intuitive results. The application of the key performance indicators can be used to carry out process diagnostics and process improvement activities. As a conclusion, a conceptual framework for carrying out optimization procedure within the coarse comminution and classification process is presented. The development of the optimization system and performance measuring system can be useful for process optimization and process improvements for industrial applications

Gas Flows in Microsystems

International audienc

Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

NASA Tech Briefs, September 2010

Topics covered include: Instrument for Measuring Thermal Conductivity of Materials at Low Temperatures; Multi-Axis Accelerometer Calibration System; Pupil Alignment Measuring Technique and Alignment Reference for Instruments or Optical Systems; Autonomous System for Monitoring the Integrity of Composite Fan Housings; A Safe, Self-Calibrating, Wireless System for Measuring Volume of Any Fuel at Non-Horizontal Orientation; Adaptation of the Camera Link Interface for Flight-Instrument Applications; High-Performance CCSDS Encapsulation Service Implementation in FPGA; High-Performance CCSDS AOS Protocol Implementation in FPGA; Advanced Flip Chips in Extreme Temperature Environments; Diffuse-Illumination Systems for Growing Plants; Microwave Plasma Hydrogen Recovery System; Producing Hydrogen by Plasma Pyrolysis of Methane; Self-Deployable Membrane Structures; Reactivation of a Tin-Oxide-Containing Catalys; Functionalization of Single-Wall Carbon Nanotubes by Photo-Oxidation; Miniature Piezoelectric Macro-Mass Balance; Acoustic Liner for Turbomachinery Applications; Metering Gas Strut for Separating Rocket Stages; Large-Flow-Area Flow-Selective Liquid/Gas Separator; Counterflowing Jet Subsystem Design; Water Tank with Capillary Air/Liquid Separation; True Shear Parallel Plate Viscometer; Focusing Diffraction Grating Element with Aberration Control; Universal Millimeter-Wave Radar Front End; Mode Selection for a Single-Frequency Fiber Laser; Qualification and Selection of Flight Diode Lasers for Space Applications; Plenoptic Imager for Automated Surface Navigation; Maglev Facility for Simulating Variable Gravity; Hybrid AlGaN-SiC Avalanche Photodiode for Deep-UV Photon Detection; High-Speed Operation of Interband Cascade Lasers; 3D GeoWall Analysis System for Shuttle External Tank Foreign Object Debris Events; Charge-Spot Model for Electrostatic Forces in Simulation of Fine Particulates; Hidden Statistics Approach to Quantum Simulations; Reconstituted Three-Dimensional Interactive Imaging; Determining Atmospheric-Density Profile of Titan; Digital Microfluidics Sample Analyzer; Radiation Protection Using Carbon Nanotube Derivatives; Process to Selectively Distinguish Viable from Non-Viable Bacterial Cells; and TEAMS Model Analyzer

Gas Turbines

This book is intended to provide valuable information for the analysis and design of various gas turbine engines for different applications. The target audience for this book is design, maintenance, materials, aerospace and mechanical engineers. The design and maintenance engineers in the gas turbine and aircraft industry will benefit immensely from the integration and system discussions in the book. The chapters are of high relevance and interest to manufacturers, researchers and academicians as well