Date of Original Version



Technical Report

Abstract or Table of Contents

Abstract: "As part of the preliminary design, the designer must evaluate the benefits of many alternative design configurations, each of which may depend on a large number of design variables. Even after many alternatives are discarded using qualitative or experiential reasoning, the designer may have to further restrict his alternatives by performing a preliminary quantitative evaluation. Even very simplified design equations may be puzzling to an inexperienced designer in that a change in any one of the design variables will often influence many functional requirements. As a result, it is difficult to evaluate the merits of the design without more detailed analysis. Experienced designers, on the other hand, are often able to identify important relationships which govern or limit design performance.Identifying important relations, such as a critical ratio or difference, not only contributes to convenience and expediency, but preserves the physical reasoning associated with the design activity and helps focus the designer's creativity toward the governing or limiting aspects of the proposed solutions. A computer based system has been developed to assist the designer in identifying important design relationships. The system operates on a set of simplified design equations to produce sets of transformed equations in terms of some alternative design variables. The alternative variables are chosen for physical significance and for correspondence to functional behavior. The transformed sets of equations can be thought of as providing an alternative view of the design configuration.They are expected to enhance the physical insight of the designer, to help in identifying governing relationships among design variables and function, and to assist the designer in evaluating performance limitations of alternative design configurations."