Posted by Rapid Generation and Optimisation of Ship Compartment Configuration based on Life Cycle Cost and Operational Effectiveness
Methods and Models II Track
Abstract:
It has been well established that the majority of Life Cycle Cost (LCC) is incurred during the in-service period. Among other factors, this is strongly linked to the design of the ship and the decisions made during the early design phase. In particular, compartment configuration can have a significant effect on LCC. Poorly considered compartment configuration and hull selection can result in hydrodynamic efficiencies which significantly increase energy consumption and hence fuel costs. Associated space limitations, inadequate or non-existent removal routes and other accessibility problems may result in expensive equipment overhaul and replacement procedures, invasive removal methods, longer maintenance availabilities and increased maintenance costs. Current design methods and decision analysis techniques focus mainly on the trade-off between operational effectiveness and acquisition cost rather than LCC. Furthermore, the process of generating valid concept designs can be labour intensive, requiring a considerable amount of time and labour on the part of a human designer which limits the number of design variables able to be considered.
This paper explores a methodology that combines existing and proven techniques to rapidly generate and objectively compare valid ship compartment configurations in consideration of the effects on LCC. Development of the proposed methodology will allow for the investigation of the link between compartment arrangement and LCC as well as providing a tool that is capable of determining optimal ship concept designs based on minimising LCC and maximising operational effectiveness.
The proposed methodology utilises life cycle costing techniques and a genetic algorithm within a Multi Criteria Decision Analysis (MCDA) framework to rapidly progress from user defined operational requirements to recommended value for money concept designs with minimal human effort. This builds on the “Inside-Out” approach to ship design whereby the compartments and systems that constitute the ship’s capability are arranged before being ‘wrapped’ in a suitable hull form. The method proposed by this paper attempts to improve the early stage ship design process by incorporating an automated method for rapidly generating feasible compartment configurations into MCDA. This allows for the comparison of a broader range of candidate designs as well as the trade-off and exploration of LCC drivers. Since a greater number of possibilities are considered, the method may find superior designs compared to the standard MCDA approach whilst identifying and characterising undesirable compartment configurations.
The commonly used approach for the task of automatic compartment allocation in ship design is to first define a quantitative measure of goodness or utility of an arrangement, then vary the configuration such that this utility is maximised by using a computational algorithm. The proposed methodology attempts to design this measure of utility and adapt a computational algorithm to this task in order to facilitate the optimisation of concept designs based on LCC and operational effectiveness.
Author(s):
Aidan Depetro
BMT Design & Technology
Aidan graduated from Royal Melbourne Institute of Technology with a BEng in Mechanical Engineering and has completed his SCEA certification. He is a Certified Cost Estimator/Analyst (CCEA) and is working towards Chartered Professional Engineer (CPEng) status.
Aidan worked as a process improvement engineer for the Ford Motor Company in Australia where he implemented best practice replication projects and completed cost-benefit analyses for a number of key improvement initiatives. He joined BMT Design & Technology as a Mechanical Engineering Consultant in 2008 and worked on a number of engineering projects including detailed designs, engineering assessments and cost-benefit analyses for the Royal Australian Navy.
He spent a period of time working in the United Kingdom for BMT Reliability Consultants where he completed a number of Defence and industry related projects including cost benefit and quantitative risk analysis of toxic gas alarm system designs for the oil and gas industry, verification and validation of a major in service support cost model and mathematical modelling of costs, risk, emissions and other parameters using MS Excel and MATLAB.
Since returning to Australia, Aidan has undertaken cost modelling and risk analysis for a number of key government projects. He was the technical lead on a major fleet-wide risk analysis and cost estimating project for the Royal Australian Navy for which he adopted a risk based approach to assess the viability of Life Of Type Extension (LOTE) for nine classes of ship in the RAN.
Aidan completed research on the relationships between icebreaking ship power, icebreaking thickness and displacement. This was incorporated into a detailed cost analysis based on concept phase requirements and principle aspects for a key Australian icebreaker project.
He developed a combined cost and operational effectiveness model for the evaluation of amphibious afloat capability replacement alternatives for the Royal Australian Navy.
Aidan was also a key developer of BMT Design & Technology’s a submarine design exploration application. The application processes key submarine design and performance parameter user inputs using submarine engineering principles, hydrodynamic relationships, historical data and cost estimating relationships to calculate the principle dimensions, key features and approximate cost of submarine concepts.
Rhyan Hoey
BMT Design & Technology
Rhyan graduated from The University of Melbourne with an MSc in Physics after completing the BSc at the same institution. He completed his research project as a post graduate student in the Astrophysics group of the School of Physics. He is currently working for BMT Design & Technology as a collaborator on research projects.
Rhyan’s Master of Science research work was centered on the modification of a purpose-designed numerical hydrodynamic simulation of the fluid interior of neutron stars to incorporate additional important physical properties. One key aspect of the work was the adaptation of a simplifying approximation used in meteorology to the case of a neutron star. Rhyan has experience in the application of computer programming to the solution of a range of different types of problem, and an interest in the use of computers in simulation and analysis.
Rhyan has a solid background in mathematics and statistics. As part of his studies, he has completed coursework covering areas such as computational and statistical physics to a significant degree of depth. He has applied many of the techniques and concepts covered in these subjects to problems outside of the physical sciences. He has experience with a number of different programming languages including C, C++, FORTRAN and IDL.
During the course of his Masters degree, Rhyan has worked on a number of small, self-contained research problems involving the use of numerous computational techniques in the simulation and analysis of various astrophysical phenomena. He has also spent some time working on a vacation research project at the university which involved the statistical analysis of raw data from the optical telescopes at the Keck Observatory. Rhyan has worked on a small project to provide a visual simulation of an agent-based complex system using the Processing programming language and integrated development environment.