Hybrid simulation of dissipative particle dynamics and computational fluid dynamics for friction drag reduction of polymer coatings

Abstract

Frictional drag reduction (DR) can lead to substantial fuel savings in marine vehicle propulsion. The application of polymer coatings on vehicle surfaces has been found to assist in reducing drag. However, there has been limited investigation into such non-uniform polymer drag reduction in external flows. This study proposes a novel numerical model that combines a mesoscopic method with computational fluid dynamics (CFD) techniques. The CFD portion of the model uses direct numerical simulation (DNS) and large eddy simulation (LES) methods, which are verified against reference data. Firstly, the mesoscopic dissipative particle dynamics (DPD) method is coupled with DNS and LES methods, and the finitely extensible nonlinear elastic approach is used to validate the results obtained using this DNS/LES-DPD method. The performance of the model is evaluated at three representative Reynolds numbers (180, 395, and 590) to confirm its universal applicability. The model is then used to investigate the influence of the height of the polymer region on non-uniform polymer DR. Notably, the LES method offers computational savings when the Reynolds numbers are high. The model also reveals that the polymer DR efficiency is significant even when the polymer region does not extend across the entire fluid area such as the application of polymer coating. This model represents a foundation for further research on polymer coatings DR and energy conservation of vessels.