Contents lists available at ScienceDirect Applied Ocean Research journal homepage: www.elsevier.com/locate/apor Rational processing of monitored ship voyage data for improved operation Shukui Liu a, ⁎ , Meici Loh a , Weichi Leow a , Haoliang Chen b , Baoguo Shang c , Apostolos Papanikolaou d,e a Nanyang Technological University, Singapore b International Paint Singapore Pte Ltd, Singapore c Marine Design and Research Institute of China, China d National Technical University of Athens, Athens, Greece e The Hamburg Ship Model Basin, Hamburg, Germany ARTICLEINFO Keywords: Propulsive performance analysis Mean added resistance in short-crested waves Data cleaning Resistance and thrust identity method Onboard monitoring Ship fouling ABSTRACT This paper presents a method for the rational processing of ship voyage data for improved ship operation. The proposedapproachisbasedonaphysicalmodelingmethod,inwhichtheshipresistance-propeller-enginemodel is frst developed by using available ship information and basic hydrodynamics. For the analysis of operational scenarios in realistic environmental conditions, seaway data are retrieved from WaveWatchIII® hindcast (Tolman, 2002; WAVEWATCH, 2020). The added resistances due to wind is predicted using a standard method recommendedbyITTCandtheaddedresistanceinwavesusinganewlydevelopedsemi-empiricalmethodofLiu and Papanikolaou (2020). Then, the recorded speed-power data is projected to the calm water condition based ontheresistanceandthrustidentitymethod.Inasecondstep,weapplysimple,yetrational,flteringcriteriato flteroutthedatapointspollutedbyship'saccelerations,therateofchangeofcourse,aswellaswaveconditions. Thedevelopedprocessingandflteringmethodisappliedtotheanalysisofthemonitoreddataofthreevoyages ofachemicalcarrierandtheobtainedresultsarediscussed.Theprospectsofextendingthepresentedmethodto the study of a time-varying ship speed performance and fuel consumption analysis procedure, in which hull fouling can be studied, is briefy outlined. 1. Introduction The investigation of the propulsive performance of a ship in a seaway is a classic hydrodynamic topic of concern both in ship design andinshipoperation.Shippropulsiveperformanceisinherentlyrelated to the fuel consumption, hence also the emission, by the installed propulsionsystemtoachieveacertaintransportworkormissionwhile keeping safety and navigational standards. A ship's propulsive performance, commonly expressed as speed- power performance, is always checked for new ships before delivery during sea trials following a specifc ISO procedure (International Standard Org). During the last two decades, however, more and more attempts have been devoted to the analysis of ship's propulsive performance of existing ships in realistic operational con- ditions,partlyduetothevolatilefuelcostandmorerecentlybecauseof the introduction of international regulations enforcing the reduction of Green House Gas (GHG) emission from maritime activities (International Maritime Organization, 2009, International Maritime Organization, 2011). Rapid technology developments during the same period enabled the installation of powerful measuring and monitoring systems onboard to record the full-scale ship performance under actual weather conditions, to transfer the recorded data to the shore via sa- tellite/cloud and to enable the refned analysis and assessment of the speed/power performance system on-land, if not by relevant systems onboard. Thepropulsiveperformanceofashipistheresultoftheinteraction of a ship's propulsion system (engine/propeller) with the hydro- dynamics of ship's hull. Essentially, a ship's engine and propeller need togeneratetherequiredthrustfortheshiptoovercometheexperienced resistance when sailing at a certain speed. When dealing with the analysisofaship'sperformance,therearemanyaspectstofocuson.For the analysis of propeller performance, see, e.g. Logan (Logan, 2011); regardingtheanalysisofenginedataandonboardenergymanagement, see, e.g. Fonteinos et al. (2017); for the statistical analysis of opera- tional data, see, e.g., Petersen et al. (2012); Mao et al. (2016) and Bialystocki and Konovessis (2016); for the mining of operational data https://doi.org/10.1016/j.apor.2020.102363 Received 31 May 2020; Received in revised form 19 July 2020; Accepted 31 August 2020 ⁎ Corresponding author. E-mail addresses: skliu@ntu.edu.sg, liushukui@deslab.ntua.gr (S. Liu), MLOH007@e.ntu.edu.sg (M. Loh), M170059@e.ntu.edu.sg (W. Leow), Haoliang.chen@akzonobel.com (H. Chen), papa@deslab.ntua.gr (A. Papanikolaou). Applied Ocean Research 104 (2020) 102363 0141-1187/ © 2020 Elsevier Ltd. All rights reserved. T