The use of virtual prototypes in product development has been proliferating rapidly in the last two decades. New computational methods and tools have been developed to generate virtual prototypes for various engineering analysis, simulation and optimization tasks. Virtual prototypes can represent several aspects of products, including among others; geometric and structural properties, physical operations and behavior, and production, use and maintenance processes. The development of methods and tools is continuously expanding towards new application domains and users are getting more and more involved in testing virtual prototypes of products. Numerical computations are getting more accurate and reliable. Through the analyses and simulations of virtual prototypes, design engineers are now able to ensure that a product will possess exactly the desired functions, properties, behaviour, quality and cost. In the hope of new opportunities, multi-disciplinary, transdisciplinary and trans-domain knowledge transformation has become one of the central topics of scientific research in virtual prototyping. Typical examples of multiand transdomain knowledge transformation are based on: (i) generalization of methods (e.g., design of computer experiments), (ii) introduction of novel technologies to enable simulation of complex physical phenomena (e.g., multiple contact in ropes), (iii) development of multi-physics solvers that facilitate the analysis of multi-faceted systems, and (iv) integration of interactive virtual testing of concepts into the product validation processes. In the field of computer-aided engineering analysis and simulation, multi-disciplinary transformation of knowledge involves the following activities: (1) identification of opportunities for integration of knowledge of multiple disciplines, (2) exporting knowledge among various mono-disciplinary applications, and (3) combining monodisciplinary knowledge to enable multi-disciplinary simulation and optimization. It has to be noted that the mono-disciplinary analysis and simulation methods are also further refined. The new methods and tools allow us to model, simulate and optimize the operations of complex engineering systems, such as internal combustion engines, industrial process plants, multi-product packaging systems, smart robotic systems, etc. In this Special Issue, we provide examples of multi-, and trans-disciplinary and trans-domain knowledge and numerical computation technology transfer in the field of engineering analysis and simulation, in addition to presenting results of the efforts towards enhancing mono-disciplinary analysis and simulation approaches. Furthermore, we intend to show that the methods and tools proposed by the contributing authors are not only significant from an academic point of view, but are also valuable for the industrial practice. The selected papers cover a wide range of application fields, indicating the importance of multi-domain knowledge enrichment and transfer. Originally, the papers were presented at the Ninth International Symposium on Tools and Methods of Competitive Engineering (TMCE 2010), that was held in Ancona, Italy, from 12 until 16 April, 2010. The TMCE 2010 Symposium was jointly organized by the Universita Politecnica delle Marche, Italy, and the Delft University of Technology, the Netherlands. The papers have been thematically arranged in this special issue. The first five papers are representative examples of knowledge enrichment. They focus on monoZ. Rusak (&) I. Horvath Delft University of Technology, Delft, The Netherlands e-mail: Z.Rusak@tudelft.nl