The increasingly stringent requirements in terms of flexibility and efficiency for hydraulic turbines pose new challenges for designers. Although computational fluid dynamics has offered new opportunities to significantly improve the performance in the preliminary design phase, the design of a hydraulic turbine still represents a challenging task requiring considerable engineering input and know-how. In such a scenario, the inverse three-dimensional design strategy has recently demonstrated its effectiveness in improving the machine performance, and interesting applications have been proposed for Francis turbines and reversible pump turbines. This paper presents and discusses the most interesting design solutions so far documented. The influence of blade staking and load distribution on the hydrodynamic performance is discussed. Finally, optimized blade load distributions are reported to provide useful design guidelines for the development of the new generation of hydraulic turbines.

Giovanni Antonio Scopoli (1723–1788) was one of the most versatile naturalists in eighteenth-century Italy. In 1785, Scopoli conceived the ambitious publication, Deliciae florae et faunae insubricae. Appearing in instalments, this included descriptions and illustrations of plants, animals and minerals found in northern Italy. Unfortunately, Scopoli's sudden death halted publication of the Deliciae after its third instalment. Recently, a corpus of 98 paintings, in the gouache style, were discovered in the Biblioteca Universitaria of Pavia. These gouaches appear to be the basis for plates planned in future instalments of the Deliciae. Marginal notes in Scopoli's handwriting are included. Because Scopoli's plant and animal specimens have been destroyed or dispersed, these drawings are crucial for reconstructing his scientific opus. Combined with other documents, Scopoli's marginal notes also reveal his exacting standards. He criticized the way his artists had poorly rendered the scientific details of the paintings.