Early-Stage Design of Novel Vessels: How can we Take a Step Forward?

Abstract

The aim of this paper is to discuss the challenges associated with the early-stage design of novel and reliable vessels, and discuss the expected benefit of the application of multi-fidelity models in this specific problem. During early-stage design of novel or complex vessels, the naval architect aims to explore the multi-dimensional design space to identify the most promising solutions and identify key trade-offs. The goal is to understand the relationship between the design drivers and the key performance indicators (KPIs) which will lead to the formulation of the main design decisions. This analysis is typically performed with the help of bespoke early-stage design tools. Traditionally, early-stage design tools are computationally cheap, but lack in accuracy. These tools have been developed based on gained design knowledge such as empirical and semi-empirical methods, historical data, and experts’ opinions. However, for the design of novel vessels, these tools are not sufficient because they have typically been developed based on the experience gained from traditional vessels. The early-stage design of novel vessels is challenging because there is very limited existing knowledge about both the design drivers and the KPIs due to their inherent nature of being “novel”. The first part of the paper discusses the challenges associated with the design of novel vessels. Two novel hull designs were examined as qualitative case studies, namely the USS Zumwalt (DDG1000) and Littoral Combat Ship (LCS) – Independent variant, to identify the design drivers and KPIs connected with the design of novel vessels by following a bottom-up approach. Ensuring the vessel’s reliability is a major design aspect for all novel designs. To achieve this, analysis via high fidelity tools is traditionally required. Typically, high fidelity tools are used later on in the design process due to their high computational requirements and the detailed design information required. However, the application of multi-fidelity models (MFMs) in the design process is a promising technique in order to introduce high fidelity models earlier on in the design process. The second part of the paper focuses on an extended literature review on the application of the multi-fidelity models to the design of complex engineering systems. Finally, the most promising methods for this specific problem are identified and discussed.

Finding Dangerous Waves—Review of Methods to Obtain Wave Impact Design Loads for Marine Structures

“…A more general discussion about the application of MFM to unconventional ship design is provided by Ref. [146].…”

Leveraging the concept of information entropy to improve a multi-fidelity design framework for early-stage design exploration of complex vessels

“…The difficulty lies in striking a balance between attaining the necessary accuracy and managing computational costs, given our constraints in terms of both computation and time. When designing novel vessels, it becomes essential to incorporate HF analysis early in the process to effectively capture design trends Charisi et al (2022a). However, achieving the required accuracy through HF tools results in escalated costs.…”

“…Thus, entropy can form a criterion to make an informed decision regarding the termination of the optimization process. Furthermore, the authors advocate for using entropy as an indicator for optimizing the covariance matrix via the optimization of the kernel function, as an extension of the method proposed in Charisi et al (2022b). The technical details of the framework are elucidated in the following section.…”

“…The authors suggest that entropy can be considered as a suitable mathematical formulation for this purpose. Furthermore, as an expansion of Charisi et al (2022b), we suggest that entropy can act as an indicator to perform kernel optimization throughout the optimization process.…”

Revisiting Large Scale Defence Acquisition: Uncertainty and Acquisition Responsiveness

“…Another is moving the physics underpinning ship acquisitions decision further "to the left" (Morris, 2019). Creating tools and processes for early-stage design that enable engineers, architects, and decision-makers to collaborate (le Poole et al, 2022;Mathieson, 2021) using a single source of data encapsulated in a model (Charisi et al, 2022), and use digital simulations of the ship to optimise the design (Papanikolaou et al, 2020;Parsons et al, 2021;Parsons et al, 2020). Keane and Tibbitts (2022); (Keane et al, 2017;Nichols et al, 2021) have pushed that designs that make more use of modular and open architecture concepts can facilitate inevitable future updates to platforms.…”