Full-scale simulation of self-propulsion for a free-running submarine

TLDR

Predicting full‑scale marine vessel self‑propulsion during design is crucial, and high‑performance computational techniques now enable ship‑free running simulations focused on this performance. This study aims to present CFD simulation results for a full‑scale submarine propelled by a high‑skew propeller. An in‑house CFD code employing a dynamic overset grid simulates propeller rotation, with model‑ and full‑scale resistance and open‑water performance studies forming a systematic convergence study and full‑scale runs incorporating skin‑friction correction. The simulations predict self‑propulsion performance at both model and full scales, showing only small discrepancies with existing data and highlighting differences in propeller performance, pressure distribution, boundary layer, and wake flow between model and full‑scale runs.

Abstract

It is important to predict the self-propulsion performance of full-scale marine vessels during the design stage. With the development of high-performance computational techniques, full-scale ship-free running simulations focused on self-propulsion performance are receiving increased attention. This study presents the results of computational fluid dynamics (CFD) simulations for a full-scale submarine propelled by a high-skew propeller. An in-house CFD code with the dynamic overset grid approach is used to simulate the rotational motion of the propeller. First, model- and full-scale simulations focused on submarine resistance and propeller open-water performance are conducted, enabling a systematic convergence study of the model. The self-propulsion performance is then predicted at the model scale, and comparisons with other available results show only small discrepancies. Finally, full-scale submarine self-propulsion simulations are conducted and the results are compared with those from the model-scale simulations with the addition of skin friction correction. Discussions on the differences between model- and full-scale self-propulsion results are presented including propeller performance, pressure distribution, boundary layer, and wake flow.