A knowledge based database system for engineering correlations
Introduction
Correlations based on empirical data are used in heat transfer and in many other engineering domains, for example fluid flow (Miller [1]). Recent development of powerful learning algorithms for artificial neural networks (ANNs) has led to their use in many engineering applications. Thibault and Grandjean [2] employed them to model three problems in heat transfer ranging from the thermocouple to correlations in natural convection. However the process of selecting the most appropriate correlation from relevant publications often presents an engineer with two major problems. Firstly, the number of publications from which the correlations may be extracted is vast. Secondly, correlations contained in individual publications are mostly specific to a particular applicability conditions.
Ideally an intelligent information system needs to be set-up to assist with the retrieval of appropriate correlations and the subsequent determination of the salient design parameter such as heat transfer coefficient, based on a simple description of the domain, say geometry and flow conditions. If such an information system is not to become rapidly out-of-date it must be capable of incorporating newly published information without the need to redesign the system. This feature is usually associated with databases than with knowledge based systems.
Furthermore, in cases where none of the information contained within the system matches the user enquiries, it would be useful for the system to suggest the best approximation by interpreting the heat transfer process described and applying appropriate knowledge. This necessitates an understanding of how and to what degree changes in geometry and flow conditions can affect the parameters and this information should be represented in a knowledge base.
This paper describes the development of an information system, specifically to jet impingement, which satisfies these objectives. The system developed combines the features of a database system with respect to data storage with that of a deductive capability of a knowledge based system (KBS).
Section snippets
Related work
Databases containing either abstracts from documents or the full text are commercially available. Documents may be selected by matching boolean combinations of words with either the words in the text or with the indexing keywords associated with a document. Searches of this kind are often limited in their effectiveness; recall rates (the proportion of the relevant documents in the database actually retrieved) of about 51% on average were found by Fenichel [3].
Two problems identified with
The use of correlations in design
Jet impingement is used where high rates of heat transfer are required, for example in the cooling of gas turbine blades, the protection of aircraft from build-up of ice by heating external surfaces, the cooling of computer components and in the heat treatment of metals. Jet impingement heat transfer occurs when one or more fluid jets are directed onto a surface at a different temperature to that of the jet.
Empirical data, generally obtained through meticulous experimentation (eg Ashforth-Frost
Jet impingement knowledge based database system
A knowledge based database system (KBDS) was developed (Moss [22]) to overcome limitations normally associated with searches of conventional databases, in particular when applied to the retrieval of appropriate correlation data for engineering design.
Validation of new correlation data and the controlled adaptation of the knowledge based front end to process this data
If the database is not to become rapidly out-of-date, new data must be added as it becomes available. The database has been integrated with the knowledge-based front-end to ensure that the entry of a new correlation into the database is complete and in the correct form. This in turn will enable the knowledge base to assist the user in subsequent retrieval of the new correlation. This in turn will enable the knowledge base to assist the user in subsequent retrieval of the new correlation. This
Discussion
Text oriented database query systems permit users to select relevant references through the construction of multiple queries, but manual formation of queries is often made more difficult by the fact that different terminology, symbols and units are used in various publications. Work has been carried out to develop expert interfaces to full text databases (Gauch [8], Smith et al. [6], Lucarella and Morara [9]), which assist the search of the literature. However the numerical values of parameters
Conclusions
A knowledge based database system has been developed which considerably reduces the effort required to obtain correlation data. Based on a simple description outlining the important geometric and flow features, the system automatically retrieves all the relevant and valid correlations from a database. The system then evaluates each of these correlations to give Nusselt number and values of the heat transfer coefficient. The system performs satisfactorily for a variety of empirical data
Acknowledgements
The research fellowship held by Dr. M.A. Moss was funded by the Polytechnics and Colleges Funding Council under their special research initiative and is gratefully acknowledged.
References (23)
- et al.
A neural network methodology for heat transfer data analysis
Int J Heat Mass Transfer
(1991) Expert database systems: knowledge/data management environments for intelligent information systems
Information Systems
(1990)- et al.
A review of heat transfer data for single circular jet impingement
Int J Heat Fluid Flow
(1992) - et al.
The implementation of a deductive database for engineering correlations
Engng Appl Artif Intell
(1992) - Miller DS. Internal flow systems. British Hydrodynamics Research Association,...
Online searching: measures that discriminate among users with different types of experience
Jasis
(1981)- Parsaye K, Chignell M, Khoshafian S, Wong H. Intelligent databases. New York: Wiley,...
- Humphrey SM. Illustrated description of an interactive knowledge-based indexing system. In: Proceedings of the ACM...
- et al.
Bibliographic information retrieval systems: increasing cognitive compatibility
Papers from the 29th NFAIS Ann. Conf. Arlington, VA, Information services and use
(1987) - Smith PJ, Shute SJ, Galdes D, Chignell MH. In search of knowledge-based search tactics. In: Proceedings of the 12th...
Cited by (5)
Development of an integrated knowledge-based system for mold-base design
2004, Journal of Materials Processing TechnologyA knowledge based system for the documentation of research concerning physical and chemical processes-system design and case studies for application
2003, Computer Aided Chemical EngineeringResearch on the integration of product concept design and particular design driven by CAI technology
2016, Jixie Gongcheng Xuebao/Journal of Mechanical EngineeringInvestigation on the development of knowledge-based engineering and its application in rapid design of process chamber of IC equipment
2013, Applied Mechanics and MaterialsKey technologies in KBE and its application
2002, Chinese Journal of Mechanical Engineering (English Edition)