Showing papers on "Conceptual design published in 1978"

Principles of Database Conceptual Design

Abstract: Criteria and methodologies for the conceptual design of databases, particularly in large and sophisticated applications, are addressed. For a design to be understandable to user and designer alike, intuitive methods for abstracting concepts from a mass of detail must be employed. Two abstraction methods are particularly important — aggregation and generalization. Aggregation forms a concept by abstracting a relationship between other concepts (called components). Generalization forms a concept by abstracting a class of other concepts (called categories). The principle of "object relativity" is essential for the successful integration of abstractions. This principle states that individuals, categories, relationships and components are just different ways of viewing the same abstract objects. Using this principle a design may be hierarchically organized into independently meaningful abstractions. An "abstract syntax" is introduced to specify these abstraction hierarchies. An advantage of this abstract syntax is that some concepts do not have to be arbitrarily classified as "roles". The principle of "individual preservation" is a minimal requirement for maintaining the semantics of aggregation and generalization. It states that every user-invokeable operation must preserve the integrity of individuals. A methodology for designing an abstract syntax specification is outlined. The simplicity of this methodology is directly due to the principles of object relativity and individual preservation.

Energy Efficient Engine Preliminary Design and Integration Studies

Abstract: The technology and configurational requirements of an all new 1990's energy efficient turbofan engine having a twin spool arrangement with a directly coupled fan and low-pressure turbine, a mixed exhaust nacelle, and a high 38.6:1 overall pressure ratio were studied. Major advanced technology design features required to provide the overall benefits were a high pressure ratio compression system, a thermally actuated advanced clearance control system, lightweight shroudless fan blades, a low maintenance cost one-stage high pressure turbine, a short efficient mixer and structurally integrated engine and nacelle. A conceptual design analysis was followed by integration and performance analyses of geared and direct-drive fan engines with separate or mixed exhaust nacelles to refine previously designed engine cycles. Preliminary design and more detailed engine-aircraft integration analysis were then conducted on the more promising configurations. Engine and aircraft sizing, fuel burned, and airframe noise studies on projected 1990's domestic and international aircraft produced sufficient definition of configurational and advanced technology requirements to allow immediate initiation of component technology development.

The Canadian high speed magnetically levitated vehicle system

Abstract: Describes a technically feasible high speed (400-480 km/h) guided ground transportation system, based on the use of the vehicle-borne superconducting magnets for electrodynamic suspension and guidance and for linear synchronous motor propulsion which has been defined as a future modal option for Canadian application A variety of sophisticated analytical techniques have been developed to establish a comprehensive theoretical base for conceptual design studies Analysis and design proposals have been validated by large-scale tests on a rotating wheel facility and by modelling system components and their interactions It is concluded that the proposed Maglev system is a sufficiently promising approach to high speed guided ground transport to warrant an assessment of its economic viability in Canada, the development of critical components (particularly lightweight superconducting magnets), and continued technical refinement

Wide area detection system: Conceptual design study

Abstract: An integrated sensor for traffic surveillance on mainline sections of urban freeways is described. Applicable imaging and processor technology is surveyed and the functional requirements for the sensors and the conceptual design of the breadboard sensors are given. Parameters measured by the sensors include lane density, speed, and volume. The freeway image is also used for incident diagnosis.

A microwave radiometer spacecraft

Abstract: A conceptual design for a future microwave-radiometer spacecraft is described. The intended remote-sensing mission is centered around soil moisture measurements and requires all-weather day and night observations at a low microwave frequency (less than 5 GHz) in order to penetrate clouds, haze, and ground covers. The specific mission requirements are summarized in terms of two broad mission objectives, the system design requirements are outlined, and three structural approaches are evaluated at the conceptual design level. The weights, Shuttle flights, and structural member lengths for the three concepts are compared. The dual momentum vector control concept for pointing and slewing control is examined.

Conceptual design of advanced central receiver power system. Final report

Abstract: The design of a 300 MWe tower focus power plant which uses molten salt heat transfer fluids and sensible heat storage is described in detail. The system consists of nine heliostat fields with 7711 heliostats in each. Four cavity receivers are located at the top of a 155-meter tower. Tasks include: (1) review and analysis of preliminary specification; (2) parametric analysis; (3) selection of preferred configuration; (4) commercial plant conceptual design; (5) assessment of commercial-sized advanced central power system; (6) development plan; (7) program plan; (8) reports and data; (9) program management; (10) safety analysis; and (11) material study and test program. (WHK)

Optical Design Considerations For Laser Fusion Reactors

Abstract: The plan for the development of commercial inertial confinement fusion (ICE) power plants is discussed, emphasizing the utilization of the unique features of laser fusion to arrive at conceptual designs for reactors and optical systems which minimize the need for advanced materials and techniques requiring expensive test facilities. A conceptual design for a liquid lithium fall reactor is described which successfully deals with the hostile x-ray and neutron environment and promises to last the 30 year plant lifetime. Schemes for protecting the final focusing optics are described which are both compatible with this reactor system, and show promise of surviving a full year in order to minimize costly downtime. Damage mechanisms and protection techniques are discussed, and a recommendation is made for a high f-number metal mirror final focusing system.

Conceptual design of a shipping cask for rail transport of solidified high level waste

Abstract: A shipping cask uniquely designed to transport solidified high level waste (SHLW) from reprocessing spent LWR fuel has not yet been developed. Battelle, Pacific Northwest Laboratory (PNL) has conducted a program for the Department of Energy to develop a conceptual design for a rail cask for transporting SHLW, and to produce models and graphical displays based on the conceptual design for use at technical meetings and in public information displays. The results of this work are summarized in this paper.

The orbiting deep space relay station - A study report

Abstract: This paper is an interim report on a study being carried out to assess the requirements for tracking and communications with deep-space probes in the post-1985 time frame and to evaluate approaches to meeting those requirements. The orbiting deep-space relay station (ODSRS) is one approach to meeting those requirements that appears to have some significant advantages over ground-based stations. A detailed conceptual design of an ODSRS is compared with other tracking and communications system configuration options. The comparison includes a life-cycle cost analysis as well as operations and performance capabilities. Reported results of the study to date include a preliminary assessment of post-1985 requirements, a discussion of planned ODSRS system capabilities as well as of tracking and communications system advantages and problems that are peculiar to an OSDRS, a look at the current status of the conceptual design of the ODSRS, and a summary of the plan for the remainder of the study.

Conceptual design of a system for detecting national diversion of LWR spent fuel

Abstract: A conceptual design for detecting the national diversion of light water reactor spent fuel in water basin storage or in transit between facilities is described. This is the third in a series of reports dealing with this topic. The first report provides the spent fuel facilities and operations baseline description; the second report discusses cost and performance tradeoffs for three inspection and surveillance concepts for the detection of a national diversion of spent fuel. The conceptual design presented herein will provide a basis for future feasibility investigations and tradeoff analyses of hardware configurations and inspection options.

Conceptual design considerations and neutronics of lithium fall laser fusion target chambers

Abstract: Atomics International and Lawrence Livermore Laboratory are involved in the conceptual design of a laser fusion power plant incorporating the lithium fall target chamber In this paper we discuss some of the more important design considerations for the target chamber and evaluate its nuclear performance Sizing and configuration of the fall, hydraulic effects, and mechanical design considerations are addressed The nuclear aspects examined include tritium breeding, energy deposition, and radiation damage

Conceptual design study of a Harrier V/STOL research aircraft

Abstract: MCAIR recently completed a conceptual design study to define modification approaches to, and derive planning prices for the conversion of a two place Harrier to a V/STOL control, display and guidance research aircraft. Control concepts such as rate damping, attitude stabilization, velocity command, and cockpit controllers are to be demonstrated. Display formats will also be investigated, and landing, navigation and guidance systems flight tested. The rear cockpit is modified such that it can be quickly adapted to faithfully simulate the controls, displays and handling qualities of a Type A or Type B V/STOL. The safety pilot always has take command capability. The modifications studied fall into two categories: basic modifications and optional modifications. Technical descriptions of the basic modifications and of the optional modifications are presented. The modification plan and schedule as well as the test plan and schedule are presented. The failure mode and effects analysis, aircraft performance, aircraft weight, and aircraft support are discussed.

Maritime Patrol Airship Concept Study

Abstract: : Results of a preliminary conceptual parametric design study for a maritime patrol airship to be used by the U.S. Coast Guard or Navy are presented. Eight different Coast Guard mission profiles are considered, and an optimum airship point design is developed for each. The report discusses mission requirements, airship operational requirements, the conceptual design approach, and the parametric design study which uses a computer program to assist in optimizing the critical parameters for each airship mission design. The study includes airship sizes from 220,000 cu ft (18,000 lb vertical takeoff weight) to 3,000,000 cu ft (230,000 lb vertical takeoff weight). Results show the unique features of the Bell unballasted, reversible thrust airship design and the critical need for design optimization, owing to the sensitivity of the airship design parameters. The computer design program shows airship conceptual differences and design trends rather than absolute design configurations, since it uses the preliminary subsystem weight relationships developed for recent airship parametric studies. Although the study design trends should remain valid, additional studies are recommended to establish better subsystem weight estimates and to incorporate life-cycle costing.

Closed Brayton cycle advanced central receiver solar-electric power system. Volume II. Evaluation, selection, conceptual design, and assessment of a closed Brayton cycle advanced central receiver solar-electric power plant with coupled sensible heat storage. Final report, September 30, 1977-November 30, 1978

Abstract: The performance and design requirements for one type of terrestrial solar thermal electric power system are described. Each of the system's major subsystems are analyzed in terms of concept and performance. The method of selecting the preferred commercial-scale system is described. The preferred commercial system conceptual design is described, and its technical and cost performance evaluated. Comments on the preferred commercial system from certain electric utilities are summarized. Finally, potential improvements to improve the performance and reduce the capital cost of the system are reviewed, and possible limitations to the development of the system are examined. Appendices provide details on certain analytic techniques, cost and performance data.

The Evaluation of Design and Employment Alternative for the LVA: A Modelling Strategy

Abstract: : This thesis presents a modelling strategy for the evaluation of complex combat systems during their conceptual design phase. It proposes the use of a relatively simple auxiliary model in conjunction with a high-resolution combat simulation. The simple model is used to enhance the analyst's ability in investigating the full range of possible effects of decisions regarding various design and employment alternatives, while the complex model is implemented to validate certain tentative hypotheses formed from the auxiliary model results. This general methodology is illustrated by considering a specific system of current interest to the U.S. Marine Corps, the LVA (Landing Vehicle Assault). A simplified auxiliary model is developed which is initially applied to an evaluation of several tactical employment alternatives. The distance offshore at which the craft initiates transition and the interarrival time between incoming waves are examined in detail. The model is additionally implemented to derive the interrelationships of the LVA design parameters with the vulnerability of that system to the attrition effects of two representative defensive direct-fire weapon systems.

Superconducting generator design. Final report

Abstract: This final report, Superconducting Generator Design (RP429-2) in two volumes, is one of two competitive research efforts to evaluate the potential of superconducting generators for electric utility application. The two competitive contracts are numbered RP429-1 and RP429-2. The project was intended to result in the design of both a 300-MVA and a 1200-MVA, superconducting, two-pole ac generator. The general objectives of the project were: (1) to prepare a detailed preliminary design for a 300-MVA and an extrapolated conceptual design for a 1200-MVA superconducting generator; (2) to provide specifications for auxiliaries for each size unit; (3) to make an economic evaluation for comparison between conventional and superconducting generators in terms of user capital and operating costs; and (4) to prepare a future development plant to move from today's technology to the construction and test of a 300-MVA superconducting generator prototype. Both this project and RP429-1 have concluded that a superconducting generator for utility application is both technically and economically feasible. The report recommends that EPRI sponsor the next logical step, which is to build and test a 300-MVA superconducting generator.

Study on Utilization of Advanced Composites in Commercial Aircraft Wing Structures.

Abstract: : A study was performed to plan the effort required by commercial transport manufacturers to accomplish the transition from current construction materials and practices to extensive use of composites in wings of aircraft that enter service in the 1990 time-period. The engineering and manufacturing disciplines which normally participate in the design, development and production of a new aircraft were employed to ensure that all of the factors that would enter a Company decision to commit to production of a composite wing structure were addressed. A conceptual design of an advanced technology reduced energy aircraft provided the framework for identifying and investigating unique design aspects. A plan development effort defined the essential technology needs and formulated approaches for effecting the required wing development. Presented are two separate programs: (1) a j6int government-industry material development program, and (2) a task-oriented wing structure development program. This report presents the wing development program plans, resource needs and the supporting data for the development plans. (MM)

Information management for nuclear power stations: System Design Concept

Abstract: A study of the information management structure required to support nuclear power plant construction was performed by a joint university-industry group under the sponsorship of the Department of Energy (DOE), formerly the Energy Research and Development Administration (ERDA). The purpose of this study was (1) to study methods for the control of information during the construction and start-up of nuclear power plants, and (2) identify those data elements intrinsic to nuclear power plants which must be maintained in a structured format for quick access and retrieval. Maintenance of the massive amount of data needed for control of a nuclear project during design, procurement, construction, start-up/testing, and operational phases requires a structuring which allows immediate update and retrieval based on a wide variety of access criteria. The objective of the research described has been to identify design concepts which support the development of an information control system responsive to these requirements. A conceptual design of a Management Information Data Base System which can meet the project control and information exchange needs of today's large nuclear power plant construction projects has been completed and an approach recommended for development and implementation of a complete operational system.