Abstract: In the shape optimization design of scroll profiles, no-rationality of the single object optimization design model is analysed. A general function of conjugate curves describing the mode of scrolls based on Whewell equation is presented on the design of profiles. Alimed at the no-rationality of the single optimization design, a multiobjective optimization design model is developed. Nondominated sorting genetic algorithm, based on a sharing niche technique, is applied. Finally, an example illustrating the multiobjective shape optimization procedure of scroll profile is given.

Key words: Nondominated sorting genetic algorithm, Pareto optimal sets, Profile optimization, Scrolls, Whewell equation