Conceptual design method driven by product genes

Empirical sizing guidelines such as tail volume coefficients have long been used in the early aircraft design phases for sizing stabilizers, resulting in conservatively stable aircraft. While successful, this results in increased empty weight, reduced performance, and greater procurement and operational cost relative to an aircraft with optimally sized surfaces. Including flight dynamics in the conceptual design process allows the design to move away from empirical methods while implementing modern control techniques. A challenge of flight dynamics and control is the numerous design variables, which are changing fluidly throughout the conceptual design process, required to evaluate the system response to some disturbance. This research focuses on addressing that challenge not by implementing higher order tools, such as computational fluid dynamics, but instead by linking the lower order tools typically used within the conceptual design process so each discipline feeds into the other. In thisresearch, flight dynamics and control was incorporated into the conceptual design process along with the traditional disciplines of vehicle sizing, weight estimation, aerodynamics, and performance. For the controller, a linear quadratic regulator structure with constant gains has been specified to reduce the user input. Coupling all the disciplines in the conceptual design phase allows the aircraft designer to explore larger design spaces where stabilizers are sized according to dynamic response constraints rather than historical static margin and volume coefficient guidelines.

The objective of this research project is the development of a second generation in-duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research focused on the Advanced Coolside Process, which has shown the potential of exceeding the performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. In Task 5, Conceptual Process Design and Economic Evaluation, the economics of the CONSOL Advanced Coolside Process as a Clean Air Act compliance option were evaluated. A conceptual process design for full-scale, coal-fired applications is described. Advanced Coolside is compared to conventional Limestone Forced Oxidation (LSFO) wet FGD technology. The process economics for coal sulfur levels ranging from 1.0% to 3.5% (as-received) and plant sizes ranging from 160 to 512 gross MW were investigated, In addition, the economics of on-site versus off-site lime hydration and the cost sensitivity to delivered pebble lime and hydrate prices are investigated, Advanced in-duct sorbent injection enjoys a capital and levelized cost advantage relative to LSFO in all cases examined in this study. As a result of this study and others made during this contract, the following conclusions can be made: (1) The capital cost of Advanced Coolside is 55% to 60% less than that of LSFO and varies slightly depending on coal sulfur content and plant size. (2) The total levelized SO{sub 2} control cost advantage relative to LSFO varies from 15% to 35% over the range of coal sulfur contents and plant sizes evaluated. This cost advantage is sensitive to sorbent transportation charges. As a result, the economics are site-specific. (3) The experimental optimizations based on interim economic analyses were the key to capital and levelized cost reductions.

The major concern in the architecture, engineering, and construction (AEC) industry is time, cost, and quality. The design for industrial building project usually complex, particularly in a field of mechanical and piping process due to the large involvement of project stakeholders. The case company, which is the specialist supplier of industrial piping solution in Thailand, reported the issue of redesigns regarding to their poor project management of conceptual design process in construction project that effect to their work performance and customer satisfaction. Thus, the purpose of this study was to improve the process of conceptual design using project management concept to reduce the number of redesign in the conceptual design phase for storm drainage design projects. The new conceptual design process was introduced in 4 stages-Initialization, Identification, Translation, and Specification. These stages were clearly defined their input, process (with project management plans, tools and techniques such as checklist, tree diagram, 3D model system and expert judgment), and output.
 
 This was validated with 30 pilot projects of storm drainage design in factories and warehouses. The results revealed that, the total number of redesign was reduced from 102 to 24 under the satisfied of company?s KPI. In addition, the total cost of redesign was decreased form THB 1,326,000 to THB 31,200. Furthermore, the total design time from the start to finish the specification output was reduced from 327 days to 212 days. Therefore, the proposed solution was proved to be practical and fully implemented by the company.

As design requirements and affordability for future aircraft become increasingly demanding, aircraft design processes will be required to explore a larger design space and capture multi-disciplinary effects during conceptual design to effectively assess the benefits of new technologies. Lockheed Martin is currently participating in the ESAVE (Efficient Supersonic Air Vehicle Exploration) AFRL program which is developing MDO-based improvements to the fighter strike conceptual design process. This paper discusses the program progress to date of both conceptual design process improvements for fighter/strike aircraft and the application of the resultant MDO process to a specific design problem. The fighter/strike design process involves many coupled discipline interactions due to demanding mission performance requirements. The ESAVE program has focused on capturing the discipline interactions required for the active structures and variable cycle engine technologies. Initial results demonstrate that integration of these structural and propulsion technologies in an MDO-based framework expands the traditional fighter/strike design space and can potentially provide significant performance improvements compared to conventional conceptual design processes.

An expert system for the conceptual design of bridges

In current day’s Unmanned Aerial Vehicle (UAV) are widely used in every field, almost from military till the commercial purpose. Usage of UAV has decreased the burden on the human, where the manpower and risks during critical conditions (war fields) are reduced. Therefore the demand for the development of the unmanned aerial Vehicle is high. Interpreting the conceptual design data of UAV is difficult because of lack of availability of their data sheets. This paper is addressed to develop a conceptual design process of high-performance UAV, which carries a maximum payload of about 300kg and can travel for the maximum range 900km/hrs. For about 50 hours of maximum endurance. Where these three parameters are considered as the main requirements. By drawing constraint diagram, feasible design space for the aircraft was frozen; using which initial sizing of the wing, wing airfoil selection, and a suitable power-plant selection was done. Fuselage design was carried out looking at the available literature on the existing aircrafts. Propeller design was done to match the thrust requirements obtained from the constraint diagram. Empennage design was done to achieve the desired static margin of the aircraft. This process completes the conceptual design of UAV, where designed aircraft meets the requirement. The outcome of this paper enhances the understanding of the conceptual design process for the academicians as well as the researchers.

In order to reduce the risks and uncertainties in conceptual design of submarine rescue vehicle (SRV), the paper proposed a risk-based conceptual design method, which consisted of three focus areas: problem setup, risk assessment, risk mitigation and decision support. Conventional risk assessment tools (e.g. probability risk assessment) were not suited for initial design because of lack of data, and a safety analysis model using fuzzy-logic approach employing fuzzy IF-THEN rules was introduced to carry out risk analysis in conceptual design. Subsequently, it was investigated that the main risky factors which influenced system risk in initial design were technology level of SRV, safety of SRV, task complexity, investment and repayment. And then a risk analysis model for submarine rescue vehicle was introduced. Lastly a case was studied to demonstrate the application of the model, and the results showed that it was an effective way to reduce the risks and uncertainties in conceptual design process.

Product principle structure model (PPSM) is generally used to represent functional requirement formally in conceptual design process. The construction and optimization of PPSM is an important task in product conceptual design phase. In this paper, a new function- and graph-based product principle structure modelling and optimization method for conceptual design is proposed. According to the principle of function decomposition, IDEFO method is utilized to construct PPSM. After that, a graph-based approach is introduced to represent and optimize the PPSM. An edge represents a product component. The vertices depict joints that allow the flow of energy between components. Through the optimization of PPSM, components of a product that are redundant or cause of loss of functionality can be determined or deleted at early design stage. At last, a case study is presented to validate the proposed method.

Conceptual chemical process design in a sustainable technological world

<p>In January 2013, the City of Edmonton called for proposals for a new 300 m footbridge across the North Saskatchewan River in Edmonton, Alberta, Canada. Consultants were challenged to develop concepts that were innovative, fit the context of the deep natural river valley, and meet strict budgetary and schedule requirements. In October 2016, the longest and first multi-span stressed ribbon bridge in Canada was opened to the public. The Terwillegar Park Footbridge was designed by Stantec Consulting Ltd for the City of Edmonton and forms a key link in the river valley park system in that city. Stressed ribbon bridges can be described as precast concrete structures that are erected segmentally on cables and post-tensioned to achieve a continuous, slender, prestressed concrete structure. In this paper, the conceptual and preliminary design process of the Terwillegar Park Footbridge is described and challenges encountered in the design and construction of this elegant and innovative structure are shared.</p>

Computer-aided conceptual design (CACD) aims to increase efficiency and quality of design work but with little essential progress due to the gap between abstract concept and detailed structure. In order to tackle the problem concerned with conceptual design process and automation, this paper introduces the concept of functional surface as the information carrier to link together product function and structure and describes a product genetic model to represent and organize product information. Functional surface is used to formalize the product gene, a varied-length coding scheme for functional surface and product gene is proposed, and the design process model for conceptual design is established based on product gene. Finally, a prototype system for CACD is introduced to demonstrate how a product can be designed based on the proposed model.

Handling complexity in conceptual ship design processes requires a thorough understanding of complexity aspects in general. More than 100 scientific papers on the subject published since 1962 are, therefore, reviewed and discussed in this paper. The paper expands the understanding of complexity theory by reviewing the literature in the engineering domain. Different definitions of complexity, characteristics of complex systems, aspects of complexity in design, complexity sources, and its drivers are explored and discussed in detail. Furthermore, the findings are arranged into relevant complexity factors in ship design. Related complexity factors in ship design, are also discussed by use of examples from everyday ship design practices. This study is a theoretical elaboration to shed light on the current practice and future research direction in handling complexity in conceptual ship design processes to improve competitiveness.

This paper establishes an analytical model for component mass, takeoff weight, and performance constraints of distributed electric propulsion (DEP) propeller-driven short takeoff and landing (STOL) unmanned aerial vehicles (UAV), and develops a conceptual design method considering propulsive/aerodynamic coupling effects. The proposed approach was applied to design a 350 kilogram-class DEP UAV with STOL capability, verifying the feasibility and effectiveness of the design method. To investigate the layout design and propulsive/aerodynamic coupling characteristics of DEP UAV, three UAV configurations with different DEP arrangements are formulated and studied, and the results indicate that the flap deflection significantly increases the lift coefficient of the UAV during takeoff, and under the same total thrust and power conditions, the lift-enhancement using DEP arrangement is more significant. In addition, it is necessary to fully consider the propulsive/aerodynamic coupling effects in the conceptual design process, and this is of great significance for the future development of DEP STOL UAV.

Advanced technologies such as Active Flow Control (AFC) offer the potential to revolutionize next generation aircraft design through enhancing aircraft maneuver, control, and operation. DARPA’s CRANE (Control of Revolutionary Aircraft with Novel Effectors) program seeks to incorporate AFC into an aircraft design, then build and fly an X-Plane to demonstrate the potential capabilities and benefits of AFC technology. As a performer in the Phase and Phase 1 programs, Lockheed Martin has made significant progress on the development of a full-scale, tailless aircraft with an integrated AFC system to enable unique maneuvers without the use of conventional control surfaces. The Lockheed Martin-led team developed an approach that consisted of four key activities. 1. Design Library. Developing a multi-variate aerodynamic database (design library) for Active Flow Control. This was an offline process using CFD tools and significant HPC computing resources to model the complex aerodynamics and boundary layer affects associated with AFC. Response Surface Models were developed to integrate the aerodynamic effects of AFC into the Conceptual Design Process. 2. Conceptual Design Methods. Developing new methods and tools that would properly account for the effects of AFC. This included updating Stability and Control models to determine control power required and control power available, updating flight control model simulations for implementation of AFC, updated MDAO models to incorporate the changes to aero, propulsion, mass properties, and updating Operations Analysis models to model new maneuvers and behaviors achievable with AFC. These new methods were used in conducting trade studies for the design of the AFC system, the propulsion system, and the air vehicle. 3. RPV Verification. Performing test activities that help verify and calibrate our analytical methods, as well as reducing key risks. Multiple wind tunnel tests were conducted to validate the numerical simulations and gather data to capture the forces and moments generated by the various fluidic effectors on the vehicle. A subscale, dynamically scaled RPV (Remotely Piloted Vehicle) with integrated AFC was built and flown to gather additional data on aspects of interest such as flight controls and control authority, while serving as risk reduction for the larger scale X-Plane. 4. X-Plane Design. Complete the design of an AFC-enabled X-Plane. The X-Plane will serve as validation of our methods as well as demonstrate the potential for AFC to enable new and compelling mission capabilities. The work in Phase 1 matures the X-Plane design in preparation for a Preliminary Design Review. This presentation will provide an overview of the Lockheed Martin team’s progress, while highlighting challenges, solutions developed, and lessons learned under the DARPA CRANE program.

This paper proposes a conceptual design tool, based upon inferential design theory. It has been specifically developed for the design of production and operations systems, but its use can be extended to other engineering areas, such as mechanical and structural systems. Inferential design theory and its foundation in the inferential theory of learning are briefly outlined. Both theories are based on the idea of using specialised knowledge operators in learning and design, termed knowledge transmutations and design knowledge transmutations respectively. The 24 transmutations existing in the two theories are outlined, and a further 12 design-specific transmutations are proposed. These have been developed as a result of our research. A conceptual design process is proposed, in which design knowledge transmutations are used. A software tool for design, CREDO, is also described and an example of its use in the generation of design concepts for an after-sales service facility is presented. The conclusions discuss the initial methodological experience of using CREDO to generate design concepts. They are based on the introductory use of CREDO at Technion in Israel for teaching purposes. Directions for further research are also provided.