The impact of propulsion factors on vessel performance in waves

This paper investigates the effect of varying propulsion factors (wake fraction, thrust deduction, relative rotative efficiency) due to waves on overall vessel performance. Four different ships have been considered where experimental values of propulsion factors in waves are available. Simulations have been performed for a realistic transpacific journey to compute variation in propulsion factors and efficiencies due to waves in realistic operating conditions. The predicted energy consumption was found to vary from -12% to +4% as a result of changes in propulsion factors due to waves. The propulsion efficiency is significantly affected in the presence of waves so it is important to include the effect of changes in propulsion factors, especially thrust deduction and wake fraction, for accurate vessel performance prediction.