Automatic Implementation of Multidisciplinary Design Optimization Architectures Using piMDO Christopher Marriage Masters of Applied Science Graduate Department of Aerospace Engineering University of Toronto 2008 Multidisciplinary Design Optimization (MDO) provides optimal solutions to complex, coupled, multidisciplinary problems. MDO seeks to manage the interactions between disciplinary simulations to produce an optimum, and feasible, design with a minimum of computational effort. Many MDO architectures and approaches have been developed, but usually in isolated situations with little chance for comparison. piMDO was developed to provide a unified framework for the solution of coupled op- timization problems and refinement of MDO approaches. The initial implementation of piMDO showed the benefits of a modular, object oriented, approach and laid the groundwork for future development of MDO architectures. This research furthered the development of piMDO by expanding the suite of available problems, incorporat- ing additional MDO architectures, and extending the object oriented approach to all of the required components for MDO. The end result is a modular, flexible software framework which is user friendly and intuitive to the practitioner. It allows complex problems to be quickly implemented and optimized with a variety of powerful numerical tools and MDO architectures. Importantly, it allows any of its components to be reorganized and sets the stage for future researchers to continue the development of MDO methods.

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017. / Small and micro unmanned aerial vehicles (UAV) are rapidly becoming viable platforms for surveillance, aerial photography, firefighting and even package delivery. While these UAVs that are of the rotorcraft type require little to no extra infrastructure for their deployment, they are typically saddled with short ranges and endurance, thus placing a restriction on their usage. On the other hand, UAVs that are of fixed wing type generally have longer range and endurance but often require a runway for take-off and landing which places a restriction on their usage. This project focuses on the development of a vertical take-off and landing (VTOL) UAV demonstrator suitable for integration on a small or mini flying wing UAV (a fixed wing UAV) to counteract the take-off and landing limitations of fixed wing type UAVs. This thesis first presents a propulsion characterisation experiment designed to determine the thrust and moment properties of a select set of propulsion system components. The results of the characterisation experiment identified that the propulsion set of a Turnigy C6374 – 200 brushless out runner electric motor driving a 22 x 10 inch three bladed propeller will provide approximately 79N (8kg) of thrust at 80% throttle (4250rpm). Therefore, two of these propulsion set would satisfy the platform requirement of 12kg maximum take-off mass (MTOM). The result of the abovementioned experiment, together with the VTOL platform requirements were then used as considerations for the selection of the suitable VTOL method and consequently the design of the propulsion configuration. Following a comparison of VTOL methods, the tilt-rotor is identified as the most suitable VTOL method and a variable speed twin prop concept as the optimal propulsion configuration.

This study explored a 130-passenger advanced turboprop commercial airliner with the purposes of economic feasibility and energy efficiency. A baseline vehicle and a derivative vehicle were researched and analyzed in detail. Based on the findings of this analysis, an advanced future airliner was designed. For the advanced airliner, advanced technologies were suggested and projections of these technology benefits were implemented. Detailed performance analysis was conducted for all three aircraft. The energy efficiency of each vehicle was compared to current and future N+3 aircraft. Lastly, cost analysis was performed to observe the impact of these energy savings. The three existing and future concepts evaluated were: 1) Bombardier 80- passenger Q400 baseline, 2) An expanded 130-passenger Bombardier Q400 termed the Q400XL, and 3) an N+3 advanced 130-passenger turboprop airliner termed the N+3 Airliner. The N+3 Airliner was compared to the SUGAR High, a Boeing/NASA N+3 aircraft, in both fuel efficiency and economic feasibility. The N+3 Airliner was 22 percent more energy efficient. At current oil prices, the N+3 Airliner had nearly identical operating cost. However, at two times current oil prices, the N+3 Airliner has a slight advantage economically. Therefore, as long as the price of oil is above 2011 oil prices, $3.03 per barrel, the N+3 Airliner will be an economically viable option. / Ph. D.

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No / This paper presents a surface generation tool designed for the construction of aircraft geometry. The software generates complex geometries which can be crafted or modified by the user in real time. The surface generation is based on partial differential equations (PDEs). The PDE method can produce different configurations of aircraft shapes interactively. Each surface is generated by a number of curves representing the character lines of a given part of the aircraft shape that can be manipulated in real time. Different surfaces then blend to create the full shape of the airplane. An important function of the proposed tool is its ability to change the aircraft shape through the adjustments of parameters associated with the initial curves. The user can apply linear transformations to the curves generating the airplane through simple input from the computer keyboard and the mouse. The updated curves can then be used to generate the surface leading to different configurations of a given airplane shape. The work presents detailed descriptions on the PDE method, parametric design and manipulation of aircrafts along with graphical demonstrations of its abilities and a series of examples to illustrate the capacity of the methodology implemented.

Recent transonic airliner designs have generally converged upon a common cantilever low-wing configuration. It is unlikely that further large strides in performance are possible without a significant departure from the present design paradigm. One such alternative configuration is the strut-braced wing, which uses a strut for wing bending load alleviation, allowing increased aspect ratio and reduced wing thickness to increase the lift to drag ratio. The thinner wing has less transonic wave drag, permitting the wing to unsweep for increased areas of natural laminar flow and further structural weight savings. High aerodynamic efficiency translates into reduced fuel consumption and smaller, quieter, less expensive engines with lower noise pollution. A Multidisciplinary Design Optimization (MDO) approach is essential to understand the full potential of this synergistic configuration due to the strong interdependency of structures, aerodynamics and propulsion. NASA defined a need for a 325-passenger transport capable of flying 7500 nautical miles at Mach 0.85 for a 2010 date of entry into service. Lockheed Martin Aeronautical systems (LMAS), our industry partner, placed great emphasis on realistic constraints, projected technology levels, manufacturing and certification issues. Numerous design challenges specific to the strut-braced wing became apparent through the interactions with LMAS, and modifications had to be made to the Virginia Tech code to reflect these concerns, thus contributing realism to the MDO results. The SBW configuration is 9.2-17.4% lighter, burns 16.2-19.3% less fuel, requires 21.5-31.6% smaller engines and costs 3.8-7.2% less than equivalent cantilever wing aircraft. / Master of Science

The evaluation of how Computational Fluid Dynamics (CFD) package may be incorporated into a conceptual design method is performed. The repeatability of the CFD solution as well as the accuracy of the calculated aerodynamic coefficients and pressure distributions was also evaluated on two different wing-body models. The overall run times of three different mesh densities was also evaluated to investigate if the mesh density could be reduced enough so that the computational stage of the CFD cycle may become affordable to use in the conceptual design stage. A farfield method was derived and used in this analysis to calculate the lift and drag coefficients. The CFD solutions were also compared with two methods currently used in conceptual design - the vortex lattice based program Vorview and ACSYNT. The unstructured Euler based CFD package FELISA was used in this study. / Master of Science

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Envisioned in the next 15 to 30 years in the aviation industry, hybrid-electric propulsion offers theopportunity to integrate new technology bricks providing additional degrees of freedom to improveoverall aircraft performance, limit the use of non-renewable fossil resources and reduce the aircraftenvironmental footprint. Today, hybrid-electric technology has mainly been applied to groundbased transports, cars, buses and trains, but also ships. The feasibility in the air industry has to beestablished and the improvement in aircraft performance has still to be demonstrated. This thesisaims to evaluate the energy savings enabled by electric power in the case of a 70-seat regionalaircraft. First, energy saving opportunities are identified from the analysis of the propulsion andaerodynamic efficiencies of a conventional twin turboprop aircraft. The potential benefits comingfrom the variation of the size of prime movers and the new power managements with the use ofbatteries are studied. Also, possible aerodynamic improvements enabled by new propellerintegrations are considered. For each topic, simplified analyses provide estimated potential ofenergy saving. These results are then used to select four electrified propulsion systems that arestudied in more detail in the thesis: a parallel-hybrid, a turboelectric with distributed propulsion, apartial-turboelectric with high-lift propellers and an all-electric. Evaluating the selected hybrid-electric aircraft is even more challenging that the sizing of the different components, the energymanagement strategies and the mission profiles one can imagine are many and varied. Inaddition, the overall aircraft design process and the evaluation tools need to be adaptedaccordingly. The Airbus in-house Multidisciplinary Design Optimisation platform named XMDO,which includes most of the required modifications, is eventually selected and further developedduring the thesis. For examples, new parametric component models (blown wing, electrical motor,gas turbine, propeller, etc…) are created, a generic formulation for solving the propulsion systemequilibrium is implemented, and simulation models for take-off and landing are improved. In orderto evaluate the energy efficiency of the hybrid-electric aircraft, a reference aircraft equipped with aconventional propulsion system is first optimised with XMDO. Different optimisation algorithms aretested, and the consistency of the new design method is checked. Then, all the hybrid-electricconfigurations are optimised under the same aircraft design requirements as the reference. Forthe electrical components, two levels of technology are defined regarding the service entry date ofthe aircraft. The optimisation results for the turboelectric and the partial-turboelectric are used tobetter understand the potential aerodynamic improvements identified in the first part of the thesis.Optimisations for the parallel-hybrid, including different battery recharge scenarios, highlight thebest energy management strategies when batteries are used as secondary energy sources. All theresults are finally compared to the reference in terms of fuel and energy efficiencies, for the twoelectrical technology levels. The last part of the thesis focuses on the all-electric aircraft, and aimsat identifying the minimum specific energy required for batteries as a function of the aircraft designrange. A trade study is also carried-out in accordance with the service entry date for the otherelectrical components

<p>The development process for new aircraft configurations needs to be more efficient in terms of performance, cost and time to market. The potential to influence these factors is highest in early design phases. Thus, high confidence must be established in the product earlier than today. To accomplish this, the concept of virtual product development needs to be established. This implies having a mathematical representation of the product and its associated properties and functions, often obtained through numerical simulations. Building confidence in the product early in the development process through simulations postpones expensive testing and verification to later development stages when the design is more mature.</p><p>To use this in aerodynamic design will mean introducing more advanced physical modelling of the flow as well as significantly reducing the turn around time for flow solutions.</p><p>This work describes the benefit of using parallel computers for flow simulations in the aircraft design process. Reduced turn around time for flow simulations is a prerequisite for non-linear flow modelling in early design stages and a condition for introducing high-end turbulence models and unsteady simulations in later stages of the aircraft design process. The outcome also demonstrates the importance of bridging the gap between the research community and industrial applications.</p><p>The computer platforms are very important to reduce the turn around time for flow simulations. With the recent popularity of Linux–clusters it is now possible to design cost efficient systems for a specific application. Two flow solvers are investigated for parallel</p><p>performance on various clusters. Hardware and software factors influencing the efficiency are analyzed and recommendations are made for cost efficiency and peak performance.</p> / Report code: LiU-TEK-LIC-2006:27.