(Dr. Farrokh Mistree, advisor)
"Product Platform Concept Exploration of Automobile Engines"
Today’s market is characterized by globalization, volatility and intense competition. Companies are adopting mass customization and open engineering systems (OES) “to achieve more with less” and be competitive in this market. Product family design provides a method to mass customize a product providing more product variety in the market with a high level of design commonality between them. In this thesis, the PPCEM (Product Platform Concept Exploration Method) is adopted as a framework to design a robust product platform for an automobile engine from which product variants of the family can be easily obtained.
To illustrate the product family design of automobile engines, top-level
design specifications for automobile engine lubricated components (bearings,
pistons, valves, etc.) are determined. In this thesis the design
using PPCEM results in performance (measured primarily in maintaining optimum
oil film thickness and power losses in the sub-systems) that is fairly
insensitive for different power ratings of the engines (products) and so
achieves commonality. The synthesis of the product platform using
PPCEM involves the following activities: Design space exploration
(Market Segmentation and Design of Experiments), system modeling (engine
friction simulation- EnFAS and system approximation using metamodels like
Kriging and Response surface methods, RSM) and system synthesis (Compromise
DSP using robust design concepts). These methods help to increase
computational efficiency, increase design freedom as well as design knowledge
and provides satisficing solutions. Since the product family design
in PPCEM might depend on the system approximation, a comparative study
is also done to assess the performance, merits and difficulties of the
two different approximations (Kriging and RSM) in the product family development.
In addition research is also done to study the benefits of combining these
two approaches and evaluating their performance in this case study.
This work will provide guidelines to help the designer make a better decision
on the choice of the metamodel in other deterministic analyses.