Ocean Engineering 264 (2022) 112405 0029-8018/© 2022 Elsevier Ltd. All rights reserved. A review of ship fuel consumption models Ailong Fan a , Jian Yang b , Liu Yang a, * , Da Wu c , Nikola Vladimir d a School of Transportation and Logistics Engineering, Wuhan University of Technology, China b School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology, China c Intelligent Transportation Research Systems Center, Wuhan University of Technology, China d Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Croatia A R T I C L E INFO Keywords: Ship energy efficiency Fuel consumption model Energy consumption prediction Machine learning Knowledge map ABSTRACT The ship fuel consumption (SFC) model is crucial for research on ship energy efficiency simulation, optimisation, and carbon emission prediction. In this study, the bibliometric tool CiteSpace was used to conduct a literature review on SFC models. Based on the review, it was concluded that the current SFC models can be classified into three types: white, black, and grey boxes. Considering the different types of SFC models, the advantages and disadvantages, accuracy improvement methods, and verification methods were analysed. Furthermore, the influencing factors of the SFC models were investigated. Based on the top-down and bottom-up modelling methods, appropriate applications of the SFC models were analysed. Furthermore, the SFC models suitable for different operation stages of ships were classified based on the degree of data availability. Finally, the persisting problems in SFC models were summarised, and corresponding solutions were proposed. In addition, future research directions for SFC models were also proposed. This study can serve as a reference for research on ship energy efficiency improvement and carbon emission forecasting. 1. Introduction As more than 80% of the total world trade is carried out by ships, ships are considered the largest contributor to fuel consumption in the transportation industry (Dere and Deniz, 2019; UNCTAD, 2020). Ac- cording to the 4th IMO Greenhouse Gas (GHG) Research Report, the total greenhouse gas emissions increased from 977 million tons to 1.076 billion tons. Moreover, the total greenhouse gas emissions by the ship- ping industry increased by 10.1%. By 2050, carbon dioxide (CO 2 ) emissions will increase by approximately 90–130% compared to 2008 (IMO, 2018). The CO 2 emitted by ships accounts for 3% of the global CO 2 emissions. Reducing carbon emissions is crucial for reducing global warming (Liu He et al., 2017). Recently, the IMO set up regulations for ship energy efficiency and GHG emission reduction to promote energy conservation and emission reduction. In 2013, the IMO proposed the ship energy efficiency regulation, which introduced two mandatory energy efficiency mechanisms: the ship energy efficiency design index (EEDI) for new ships and the ship energy efficiency management plan (SEEMP) for all ships. IMO, 2021, MEPC 76 adopted the technical guidelines for the energy efficiency existing ship index (EEXI) and car- bon intensity indicator (CII). Moreover, a short-term target of a 40% reduction in shipping carbon emission intensity by 2030 and a long-term target of reducing total emissions by 50% (i.e., 70% carbon intensity) by 2050 were formulated (IMO, 2021). Clean energy sources, such as Very-Low Sulphur Fuel Oil (VLSFO), marine gas oil (MGO), and Liquefied Natural Gas (LNG), have gained popularity since 2020 (Ji and El-Halwagi, 2020; Pavlenko et al., 2020; Stolz et al., 2022). Low-sulphur and low-carbon fuels can significantly reduce the emissions of ship air pollutants (such as SO x and NO x ) and GHGs (CO 2 ) (Liu et al., 2021). Ampah et al. (2020) addressed the development and potential of ship fuels. There are some differences between traditional fossil fuels and clean fuels in the modelling of fuel consumption, which can be attributed to the different fuels having different carbon emission factors. A review of the ship fuel consumption (SFC) model is also of benefits for modelling the consumption of clean fuels. Reducing fuel consumption has become a popular research direction in shipping industry. During operation, there exists a strong relationship between the Energy Efficiency Operational Indicator (EEOI), CII, and fuel consumption of ships (Fan 2015; He et al., 2021; Fan et al., 2021a; Zhang et al., 2017). Reducing fuel consumption can reduce operational costs significantly. Therefore, optimal fuel consumption is crucial for realising energy efficiency management, cost reduction, and efficiency improvement of operational ships. Simulation models can reduce the work difficulty and operational * Corresponding author. E-mail address: yang.liu@whut.edu.cn (L. Yang). Contents lists available at ScienceDirect Ocean Engineering journal homepage: www.elsevier.com/locate/oceaneng https://doi.org/10.1016/j.oceaneng.2022.112405 Received 7 March 2022; Received in revised form 8 August 2022; Accepted 24 August 2022