Iterative designs

Technical Basis for the ITER Final Design, ITER EDA Documentation Series, No. 22, IAEA, Vienna 2001... 

Despite great strides, the problems arising from plasma-material interactions (PMIs), together with the selection of plasma facing materials, still represent major challenges for the reliable and safe operation of a D-T next-step tokamak [1]. They also remain potential obstacles for the successful development of future fusion power reactors. These issues came into sharp focus during D-T operation of the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) and, in particular, in the process of designing ITER. 

A Identify the predicted active set of models to be used in the design. All models which have shown an active constraint in any of the three previous design iterations are predicted as active. 

Process parameters Library design Iterative planning based on results from virtual or experimental libraries... 

Fig. 4.2.5 Fast design iterations using library-based design methodology...

Next, all sub-systems should be integrated and incrementally optimized. The migration based technologies would be valuable because design iteration to an earlier stage would be costly in terms of design cost and turn-around time. Finally, the chip level routing could complete all necessary connections and make the system ready for final tape-out. 

Evaluations will lead to a reexamination of requirements, narrowing of the range of design concepts under consideration, and refinement of superior concepts in a subsequent design iteration. 

While the component-level test data presented herein still show a slight performance gap to current marketplace solutions, the added challenges of innovative water management techniques managed by the concepts as proposed are illustrated as viable. The self-closing design solution continues to evolve, and design iterations are in process to drive total performance in line with current production solutions. 

The conceptual design iteration, upon which these results are based, has not yet included a detailed and optimized LBP design required to yield an MOC hot excess reactivity of < 2.5 percent Ak. Additional detailed LBP design will be required to achieve the goal of < 2.5 percent Ak. The estimates given for MOC conditions assume that this goal will be achieved after more detailed LBP design studies have been completed. 

Quite often the design of structures made of FRP profiles is driven by serviceability criteria such as maximum deflections. Therefore, it is recommended that the design iteration procedure be started using serviceability criteria. 

Undertake design iterations until aU interactions are contained or mediated by appropriate mechanisms. 

Chamley s design of an artificial hip joint was the product of an evolutionary process between 1958 and 1960 (Charnley 1979). Five design iterations occurred. Chamley s initial "double cup" design in 1958 mimick the natural joint. The acetabulum was replaced with a thin shell of PTFE and femoral head surface was replaced with a PTFE ball, as shown in Figure 4.1, taken of the collection at the Charnley Museum at Wrightington. 

In order to evaluate the quality and feasibility of this allocation and assignment, two more subtasks are performed. These provide important feedback to the designer, and they can initiate design iterations ... 

Considering the difficulties of co-ordination faced by a multidisciplinary design team, and the need to minimize design iterations by foreseeing the whole eventual plant when preparing initial layouts, pipe support systems should be substantially set out for batches of lines from the outset for example, pipes should be run on racks whenever possible. 

Smaller plants are much easier to design (smaller in the context of number of components rather than physical size or capacity), accurately and quickly, than larger plants, evidently because there are fewer internal interfaces, and therefore design iterations and interface errors are reduced. Construction organization may be simplified and site interfaces reduced, bringing benefits such as reduced interference between different contractors and more competition between smaller, more focused construction organizations. 

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