Design Ideation and Selection of Under-Piston Door for a Two-stroke Marine Engine Using Hybrid TRIZ-biomimetic and MCDM Methods

Design ideation and selection of a two-stroke marine engine under-piston door employing Theory of Inventive Problem Solving (TRIZ), biomimetics, Analytical Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is presented in this paper. The study is motivated by exploring bio-composites as potentially suitable substitutes for conventional steel in engine component manufacture. As bio-composites possess lower mechanical properties compared to steel, the geometrical redesign was deemed necessary for any potential material substitution to take place. New under-piston door designs were ideated through the synergy between TRIZ and biomimetics. Computational models were developed, inspired by the Amazon waterlily, the tortoiseshell and the spider web. Mechanical simulation was performed for maximum stress (von Mises), total deformation and volume. With the simulated results of these designs, AHP and TOPSIS provided the solution’s capabilities to decide the best design overall. The design inspired by the Amazon waterlily proved the best and showed lower stress and deformation values compared to the original by 45.25% and 4.5%, respectively. This research provided conclusive evidence that with refined scrutiny of the TRIZ and biomimetic methods, along with AHP and TOPSIS, potential alternatives to conventional materials that offer environmental friendliness without compromising operational requirements can be realised.