Development of an automated aircraft subsystem architecture generation and analysis tool

Purpose – The purpose of this paper is to present a new computational framework to address future preliminary design needs for aircraft subsystems. The ability to investigate multiple candidate technologies forming subsystem architectures is enabled with the provision of automated architecture generation, analysis and optimization. Main focus lies with a demonstration of the frameworks workings, as well as the optimizers performance with a typical form of application problem. Design/methodology/approach – The core aspects involve a functional decomposition, coupled with a synergistic mission performance analysis on the aircraft, architecture and component levels. This may be followed by a complete enumeration of architectures, combined with a user defined technology filtering and concept ranking procedure. In addition, a hybrid heuristic optimizer, based on ant systems optimization and a genetic algorithm, is employed to produce optimal architectures in both component composition and design parameters. The optimizer is tested on a generic architecture design problem combined with modified Griewank and parabolic functions for the continuous space. Findings – Insights from the generalized application problem show consistent rediscovery of the optimal architectures with the optimizer, as compared to a full problem enumeration. In addition multi-objective optimization reveals a Pareto front with differences in component composition as well as continuous parameters. Research limitations/implications – This paper demonstrates the frameworks application on a generalized test problem only. Further publication will consider real engineering design problems. Originality/value – The paper addresses the need for future conceptual design methods of complex systems to consider a mixed concept space of both discrete and continuous nature via automated methods

The House of Representatives: “Grand Depository of the Democratic Principle”?

The solar simulator is the key facility for indoor research of solar PV cells, solar heat collectors, space craft and CSP systems. This paper classifies the four types of solar simulators based on their characteristics and their design objects: space solar simulator, standard PV cell testing solar simulator, collector testing solar simulator and high-flux solar simulator. The review of solar simulator developments is mainly based on the developments of light sources and optical concentrators. The light source is the most important component for a solar simulator design; carbon arc lamp, metal halide arc lamp, quartz tungsten halogen lamp, xenon arc lamp, mercury xenon lamp, argon arc lamp and light-emitting diode lamp (LED) are used to be chosen as the light sources to meet the various requirements for the design objects. The optical concentrator is another key component; ellipsoidal reflector, compound parabolic concentrator (CPC), light cone, hyperboloid concentrator, parabolic dish concentrator and Fresnel lens are also reviewed in this paper. Finally, the near future developments of these four type solar simulators are discussed based on the requirements of research and the available technology of light sources and optical concentrators.QC 20141017</p

Phasemeter core for intersatellite laser heterodyne interferometry: modelling, simulations and experiments

Inter satellite laser interferometry is a central component of future space-borne gravity instruments like LISA, eLISA, NGO and future geodesy missions. The inherently small laser wavelength allows to measure distance variations with extremely high precision by interfering a reference beam with a measurement beam. The readout of such interferometers is often based on tracking phasemeters, able to measure the phase of an incoming beatnote with high precision over a wide range of frequencies. The implementation of such phasemeters is based on all digital phase-locked loops, hosted in FPGAs. Here we present a precise model of an all digital phase locked loop that allows to design such a readout algorithm and we support our analysis by numerical performance measurements and experiments with analog signals.Comment: 17 pages, 6 figures, accepted for publication in CQ

Energy Efficient Engine: Control system component performance report

An Energy Efficient Engine (E3) program was established to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, General Electric designed and tested a new engine. The design, fabrication, bench and engine testing of the Full Authority Digital Electronic Control (FADEC) system used for controlling the E3 Demonstrator Engine is described. The system design was based on many of the proven concepts and component designs used on the General Electric family of engines. One significant difference is the use of the FADEC in place of hydromechanical computation currently used

Hypermodular Self-Assembling Space Solar Power -- Design Option for Mid-Term GEO Utility-Scale Power Plants

This paper presents a design for scaleable space solar power systems based on free-flying reflectors and module self-assembly. Lower system cost of utility-scale space solar power is achieved by design independence of yet-to-be-built in-space assembly or transportation infrastructure. Using current and expected near-term technology, this study describe a design for mid-term utility-scale power plants in geosynchronous orbits. High-level economic considerations in the context of current and expected future launch costs are given as well. \c{opyright} 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Comment: 6 pages, 3 figures; to be published in IEEE Xplore, in Proceedings to SSP 2013 Workshop, co-located with IEEE WiSEE 2013 Conference, Nov 7-9, Baltimore, MD, US

Energy Efficient Engine (E3) controls and accessories detail design report

An Energy Efficient Engine program has been established by NASA to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, a new turbofan engine was designed. This report describes the fuel and control system for this engine. The system design is based on many of the proven concepts and component designs used on the General Electric CF6 family of engines. One significant difference is the incorporation of digital electronic computation in place of the hydromechanical computation currently used

Envisioning Futures of Design Education: An Exploratory Workshop with Design Educator

The demand for innovation in the creative economy has seen the adoption and adaptation of design thinking and design methods into domains outside design, such as business management, education, healthcare, and engineering. Design thinking and methodologies are now considered useful for identifying, framing and solving complex, often wicked social, technological, economic and public policy problems. As the practice of design undergoes change, design education is also expected to adjust to prepare future designers to have dramatically different demands made upon their general abilities and bases of knowledge than have design career paths from years past. Future designers will have to develop skills and be able to construct and utilize knowledge that allows them to make meaningful contributions to collaborative efforts involving experts from disciplines outside design. Exactly how future designers should be prepared to do this has sparked a good deal of conjecture and debate in the professional and academic design communities. This report proposes that the process of creating future scenarios that more broadly explore and expand the role, or roles, for design and designers in the world’s increasingly interwoven and interdependent societies can help uncover core needs and envision framework(s) for design education. This approach informed the creation of a workshop held at the Design Research Society conference in Brighton, UK in June of 2016, where six design educators shared four future scenarios that served as catalysts for conversations about the future of design education. Each scenario presented a specific future design education context. One scenario described the progression of design education as a core component of K-12 curricula; another scenario situated design at the core of a network of globally-linked local Universities; the third scenario highlighted the expanding role of designers over time; and the final scenario described a distance design education context that made learning relevant and “close” to an individual learner’s areas of interest. Forty participants in teams of up to six were asked to collaboratively visualize a possible future vision of design education based on one of these four scenarios and supported by a toolkit consisting of a set of trigger cards (with images and text), along with markers, glue and flipcharts. The collaborative visions that were jointly created as posters using the toolkit and then presented by the teams to all the workshop participants and facilitators are offered here as a case study. Although inspired by different scenarios, their collectively envisioned futures of what design education should facilitate displayed some key similarities. Some of those were: Future design education curricula will focus on developing collaborative approaches within which faculty and students are co-learners; These curricula will bring together ways of learning and knowing that stem from multiple disciplines; and Learning in and about the natural environment will be a key goal (the specifics of how that would be accomplished were not elaborated upon.) In addition, the need for transdisciplinarity was expressed across the collaborative visions created by each of the teams, but the manner that participants chose to express their ideas about this varied. Some envisioned that design would evolve by drawing on other disciplinary knowledge, and others envisioned that design would gradually integrate with other disciplines

Solar array electrical performance assessment for Space Station Freedom

Electrical power for Space Station Freedom will be generated by large Photovoltaic arrays with a beginning of life power requirement of 30.8 kW per array. The solar arrays will operate in a Low Earth Orbit (LEO) over a design life of fifteen years. This paper provides an analysis of the predicted solar array electrical performance over the design life and presents a summary of supporting analysis and test data for the assigned model parameters and performance loss factors. Each model parameter and loss factor is assessed based upon program requirements, component analysis, and test data to date. A description of the LMSC performance model, future test plans, and predicted performance ranges are also given

Hybrid CMS methods with model reduction for assembly of structures

Future on-orbit structures will be designed and built in several stages, each with specific control requirements. Therefore there must be a methodology which can predict the dynamic characteristics of the assembled structure, based on the dynamic characteristics of the subassemblies and their interfaces. The methodology developed by CSC to address this issue is Hybrid Component Mode Synthesis (HCMS). HCMS distinguishes itself from standard component mode synthesis algorithms in the following features: (1) it does not require the subcomponents to have displacement compatible models, which makes it ideal for analyzing the deployment of heterogeneous flexible multibody systems, (2) it incorporates a second-level model reduction scheme at the interface, which makes it much faster than other algorithms and therefore suitable for control purposes, and (3) it does answer specific questions such as 'how does the global fundamental frequency vary if I change the physical parameters of substructure k by a specified amount?'. Because it is based on an energy principle rather than displacement compatibility, this methodology can also help the designer to define an assembly process. Current and future efforts are devoted to applying the HCMS method to design and analyze docking and berthing procedures in orbital construction