Assessment of Experimental, Computational, and Combined EFD/CFD Methods for Ship Performance Prediction
Doctoral thesis, 2023

In today’s highly competitive market, alongside increasingly stringent regulatory requirements, the precise prediction of ship performance has assumed paramount importance for both design verification and operational evaluations. This thesis addresses the need for a comprehensive assessment of Experimental Fluid Dynamics (EFD), Computational Fluid Dynamics (CFD), and their combination to enhance the accuracy of performance predictions. Moreover, it explores the potential of combined EFD/CFD methods in improving power predictions by either replacing or complementing certain aspects of the existing methodology, while also introducing novel methods. The investigation identifies the Prohaska method as a prominent source of uncertainty in the ITTC-78 method. As an alternative, the CFD-based form factor method is meticulously examined, employing various codes and numerical approaches. The findings robustly establish the applicability and accuracy of the CFD-based form factor method, even when subjected to diverse numerical approaches and computational grids. Furthermore, best practice guidelines are derived for double-body RANS computations, ensuring compatibility with experimental form factors. Another debated issue within the ITTC-78 method is the very concept of form factor. This study conclusively affirms the Reynolds number dependence in form factors when the ITTC-57 line is employed. However, the numerical friction lines derived in this research, effectively eliminates these scale effects. Additionally, this study addresses conditions with flow separation, which renders the conventional form factor approach inadequate. A two form factor method (2−k method) is proposed to address instances of separated flow, complemented by an empirical correction formula for vessels with deep transom submergence and wetted transom flow. Furthermore, this thesis delves into the exploration of direct full-scale CFD computations for ship performance prediction. Extensive validation studies, encompassing numerous test cases and sea trials, are conducted to compare the accuracy of full-scale CFD computations with EFD based, and combined EFD/CFD methods. This thesis quantifies, for the first time in the literature, the difference in accuracy between fully computational and extrapolation-based methods using a large number of test cases and sea trials. The results indicate that while the prediction accuracy of full-scale CFD computations for power and RPM is lower than the other methods, the discrepancy is not substantial. Conversely, the investigations underscore that the combined EFD/CFD methods stand as the most accurate prediction method. Consequently, this thesis recommends incorporating combined EFD/CFD methods into the recommended procedures, as it offers immediate improvements to the existing ship performance prediction methods.

numerical friction line

form factor


measurement uncertainty

power prediction


verification and validation

Combined CFD/EFD Methods


Kadir Burak Korkmaz

Chalmers, Mechanics and Maritime Sciences (M2), Marine Technology

Numerical Friction Lines for CFD Based Form Factor Determination Method

8th International Conference on Computational Methods in Marine Engineering, MARINE 2019,; (2019)p. 694-705

Paper in proceeding

Investigations for CFD Based Form Factor Methods

Numerical Towing Tank Symposium,; (2019)

Paper in proceeding

CFD based form factor determination method

Ocean Engineering,; Vol. 220(2021)

Journal article

Verification and Validation of CFD Based Form Factors as a Combined CFD/EFD Method

Journal of Marine Science and Engineering,; Vol. 9(2021)p. 1-30

Journal article

Korkmaz, K. B., Werner, S., & Bensow, R. . Investigations on experimental and computational trim optimisation methods

A Validation Study of Full-Scale CFD Simulation for Sea Trial Performance Prediction of Ships

World Congress in Computational Mechanics and ECCOMAS Congress,; (2023)

Paper in proceeding

In the complex world of ship design and maritime operations, accurate ship performance prediction is the compass guiding both efficiency and environmental responsibility. It serves as the keystone in ship design, ensuring vessels meet contractual speed specifications. With global shipping accounting for approximately 3% of global greenhouse gas emissions, international regulatory bodies are pushing for energy-efficient ship designs by enforcing new regulations. Therefore, ship performance prediction methods, which encapsulate the science of foreseeing how a ship will behave in terms of speed, power, and other critical factors, has never been more critical.

The ship performance predictions have been traditionally performed by experiments on scale models, i.e., prototypes. However, the flow physics between the prototype and the full-scale ship differs, necessitating corrections for accurate translation. This thesis delves into the underlying principles of these calculations and employs computer simulations (CFD) to propose new procedures. The findings highlight the pivotal role of advanced methods like CFD in augmenting the precision of ship performance prediction. This work concludes that the incorporation of computer simulations into existing methodology is crucial for increasing the overall accuracy of ship performance prediction methods, thus aiding in meeting the new standards set by regulatory authorities and achieving a more sustainable maritime future.

Fuel reduction by trim variation - CFD, EFD and onboard logging

Swedish Energy Agency (51551-1), 2020-12-01 -- 2023-06-01.

Subject Categories

Applied Mechanics

Vehicle Engineering

Fluid Mechanics and Acoustics

Marine Engineering


C3SE (Chalmers Centre for Computational Science and Engineering)



Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5397



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