A chemical engineering design view of biotechnology

The possibilities of biotechnology are being widely discussed and promoted. Because of this there will be many studies directed at evaluating biotechnology projects. At some stage this will require the generation of potential process plant designs. The paper provides an introduction to those aspects of biotechnology which will be the concern of the chemical engineer, with an emphasis on design tasks. This is supported by a commentary on the similarities with and differences from mainline chemical engineering design. In addition the principal material relating to design has been drawn together from the available literature and summarized for engineers new to the area of biotechnology.     

Knowledge-based systems in the design activity

This paper considers the evolution of knowledge-based systems (KBS) in relation to the design activity. In order to do this effectively it commences with a definition of a core design activity in relation to products which are either conventional or novel. KBS are broken down in sympathy with the decomposition of a design, i.e., whole design, partial or sub-system design, component design. The problem of knowledge elicitation and the variability of the constraints at each level of design are considered and conclusions drawn in terms of conventional and novel products.

A hypothesis—‘to be or not to be’—is proposed covering the conceptual design spectrum which suggests that the way forward is via a system of linked KMs (knowledge modules) to be designed using multi-disciplinary teams, since it is considered that KBS are products in their own right and should be treated as such.     

Application of a systematic design methodology: an engineering case study

The basic steps of a design process have been reviewed and applied to seek an optimum solution for an industrial design problem. The problem was about a mechanical swivel-joint in a sea-current-metering system for underwater marine use. It was expensive ($200) and not functioning properly because of rattling and high friction between parts. The objective was to design another joint of better performance and lower cost, if possible. Ten steps were defined and carefully followed to solve the problem. This led to the design and production of a good quality swivel-joint as far as performance, appearance and other aspects were concerned and the cost reduced by 40%. This design method, in addition to yielding good results, is suitable for the organization of the activities of new designers and design students.     

基于系统工程过程的维修性设计要求生成过程研究

维修性设计要求的生成是维修性工作的一个重要组成部分,然而目前还没有有效的方法和过程支持该项工作的开展.借鉴系统工程过程的基本步骤,结合产品的一般研制程序,提出维修性设计要求的一体化生成过程,该生成过程包括维修方案的生成、维修性指标的确定与分配、维修性设计要求的生成三个主要工作,并对各项工作过程进行了详细的阐述.     

Rapid prototyping and flow simulation applications in design of agricultural irrigation equipment: Case study for a sample in-line drip emitter

In this study, a 3D CAD solid model of a sample agricultural irrigation emitter was created and the flow behaviour was simulated in its labyrinth channels by using a flow simulation technique. Referenced by the original design, the channel geometry was modified and the emitter was re-fabricated using rapid prototyping/additive manufacturing techniques. The flow behaviour is then re-investigated based on the re-shaped channel geometry of the labyrinth structure. The predetermined optimum pressure in the pipe was validated experimentally for both the original design and modified designs. As a result, the optimum pressure in the pipe and the flow characteristics for original both the design and modified designs of the emitter were validated. This study contributes to further research into the development of agricultural irrigation equipment aided through the utilisation of additive manufacturing and computer aided engineering tools.     

A systematic approach to preliminary polymer process development: modeling and design

A general and complete methodology is presented to facilitate systematic modeling and design of polymer processes during the early development period. To capture and handle the subjective type of uncertainty, embedded in the preliminary process development, fuzzy theories are used as a basis to model and design the process in the presence of ambiguity and vagueness. Physical membership functions are developed for mapping the relation between process variables and the associated fuzzy uncertainties. Based on the qualitative results generated using our previously proposed “linguistic based preliminary design method,” the process modeling can be followed even in the absence of any process governing equations. The modeling is carried out by establishing an appropriate fuzzy reasoning system which provides a specific functional mapping that relates input process variables to one (or more than one) output performance parameter(s). A reduced yet feasible domain is generated by our qualitative design scheme to constrain the process variables. Now, any optimization routine can then be employed to search for a proper process design. We demonstrate the effectiveness of the proposed methodology by its application to a typical compression molding process.