The unsteady aerodynamic performance of a maneuvering 1/72nd scale model of an unmanned combat air vehicle (UCAV) 1303 geometry has been studied in the Naval Postgraduate School water tunnel. Despite the numerous past publications on UCAV flows, none pertains to the UCAV maneuvering characteristics. Due to its nonslender wing, the flow features over the chosen aircraft are unique in that both features of highly yawed wings and of delta wings are present. Even though the speeds and Reynolds numbers are low in a water tunnel, the results of the present studies attest to the suitability of a water tunnel for performing such studies. Force measurements taken at various Reynolds numbers, model attitudes and maneuvering rates for comparison proved to be valid for data comparison to potential flight scenarios. The UCAV 1303 model has a 47 degrees leading edge sweep and a cranked trailing edge delta wing with a fuselage. Pitching and rolling maneuvers were performed in various combinations to demonstrate the real flight conditions of a maneuvering UCAV. A five-component strain-gage and flow monitoring software were used to determine force and moment coefficients in real time. These coefficients were analyzed and compared to previous flow visualization tests to correlate the various flow features recorded during that phase of the study, and to determine the overall stability of a delta wing UCAV. These plots demonstrate what is seen visually at Reynolds numbers from 1.17x104 to 2.94x104. Where the pitch break occurs on the wings during maneuvers is correlated and dependent on Reynolds number, as initially suspected. Performing unsteady maneuvers helped in retaining the approximate linear variation of lift coefficient to higher angles of attack. Roll maneuvers produced oscillatory side forces and moments at high angles of attack and roll, indicating potentially serious unsteady forces.

This study generated new information through qualitative documentation of the main flow features and direct measurements of the aerodynamic performance of a tailless, unmanned combat air vehicle (UCAV) 1303 configuration under both steady and unsteady maneuvering conditions. Photographic evidence of flow features, measurements of large-scale flow effects, and that of forces and aerodynamic coefficients during static and dynamic pitch, roll and yaw maneuvers were obtained. Flow visualization images and force measurements were taken at various Reynolds numbers, model attitudes and pitch rates for comparison. A 1/72nd-scale model with a 47-degree leading edge sweep and a cranked trailing edge delta wing with a fuselage was investigated in the NPS water tunnel. Phase locked, high-resolution flow images were obtained using a five color dye injection system over the maneuvering model. Both static and dynamic pitch-up, roll and yaw maneuvers were considered. Additionally, a five-component strain gage and flow monitoring software were employed to record, in real time, yawing, pitching and rolling moment information and derive the aerodynamic force and moment coefficients for selected maneuver conditions. Flow visualization revealed the presence of a strong spanwise flow at low angles of attack and strong vortical flow structures at larger angles of attack, as can be expected, but not clearly established earlier, for such low sweep angle wings. It also indicated that the vortical structures and reverse flow were highly Reynolds-number dependent. Normal force and pitching moment load data correlated well with trends observed for low sweep angle delta wings, but unexpected side force, yawing moment and rolling moment variations were observed, which were attributable to asymmetrical vortical flow behavior on the tailless UCAV geometry.

Downscaled physical models, also referred to as subscale models, have played an essential role in the investigation of the complex physics of flight until the recent disruption of numerical simulation. Despite the fact that improvements in computational methods are slowly pushing experimental techniques towards a secondary role as verification or calibration tools, real-world testing of physical prototypes still provides an unmatched confidence. Physical models are very effective at revealing issues that are sometimes not correctly identified in the virtual domain, and hence can be a valuable complement to other design tools. But traditional wind-tunnel testing cannot always meet all of the requirements of modern aeronautical research and development. It is nowadays too expensive to use these scarce facilities to explore different design iterations during the initial stages of aircraft development, or to experiment with new and immature technologies. Testing of free-flight subscale models, referred to as Subscale Flight Testing (SFT), could offer an affordable and low-risk alternative for complementing conventional techniques with both qualitative and quantitative information. The miniaturisation of mechatronic systems, the advances in rapid-prototyping techniques and power storage, as well as new manufacturing methods, currently enable the development of sophisticated test objects at scales that were impractical some decades ago. Moreover, the recent boom in the commercial drone industry has driven a quick development of specialised electronics and sensors, which offer nowadays surprising capabilities at competitive prices. These recent technological disruptions have significantly altered the cost-benefit function of SFT and it is necessary to re-evaluate its potential in the contemporary aircraft development context. This thesis aims to increase the comprehension and knowledge of the SFT method in order to define a practical framework for its use in aircraft design; focusing on low-cost, short-time solutions that don’t require more than a small organization and few resources. This objective is approached from a theoretical point of view by means of an analysis of the physical and practical limitations of the scaling laws; and from an empirical point of view by means of field experiments aimed at identifying practical needs for equipment, methods, and tools. A low-cost data acquisition system is developed and tested; a novel method for semi-automated flight testing in small airspaces is proposed; a set of tools for analysis and visualisation of flight data is presented; and it is also demonstrated that it is possible to explore and demonstrate new technology using SFT with a very limited amount of economic and human resources. All these, together with a theoretical review and contextualisation, contribute to increasing the comprehension and knowledge of the SFT method in general, and its potential applications in aircraft conceptual design in particular.

This book comprises the select proceedings of the International Conference on Materials, Design and Manufacturing for Sustainable Environment (ICMDMSE 2020). The primary focus is on emerging materials and cutting-edge manufacturing technologies for sustainable environment. The book covers a wide range of topics such as advanced materials, vibration, tribology, finite element method (FEM), heat transfer, fluid mechanics, energy engineering, additive manufacturing, robotics and automation, automobile engineering, industry 4.0, MEMS and nanotechnology, optimization techniques, condition monitoring, and new paradigms in technology management. Contents of this book will be useful to students, researchers, and practitioners alike.

Genetic algorithms are playing an increasingly important role in studies of complex adaptive systems, ranging from adaptive agents in economic theory to the use of machine learning techniques in the design of complex devices such as aircraft turbines and integrated circuits. Adaptation in Natural and Artificial Systems is the book that initiated this field of study, presenting the theoretical foundations and exploring applications. In its most familiar form, adaptation is a biological process, whereby organisms evolve by rearranging genetic material to survive in environments confronting them. In this now classic work, Holland presents a mathematical model that allows for the nonlinearity of such complex interactions. He demonstrates the model's universality by applying it to economics, physiological psychology, game theory, and artificial intelligence and then outlines the way in which this approach modifies the traditional views of mathematical genetics. Initially applying his concepts to simply defined artificial systems with limited numbers of parameters, Holland goes on to explore their use in the study of a wide range of complex, naturally occuring processes, concentrating on systems having multiple factors that interact in nonlinear ways. Along the way he accounts for major effects of coadaptation and coevolution: the emergence of building blocks, or schemata, that are recombined and passed on to succeeding generations to provide, innovations and improvements.

Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.

The book covers recent trends in the field of devices, wireless communication and networking. It presents the outcomes of the International Conference in Communication, Devices and Networking (ICCDN 2018), which was organized by the Department of Electronics and Communication Engineering, Sikkim Manipal Institute of Technology, Sikkim, India on 2–3 June, 2018. Gathering cutting-edge research papers prepared by researchers, engineers and industry professionals, it will help young and experienced scientists and developers alike to explore new perspectives, and offer them inspirations on addressing real-world problems in the field of electronics, communication, devices and networking.