Projects per year
Abstract
Numerical simulations were carried out to investigate hydrodynamic forces on submarine pipelines in oscillatory flows, with a focus on the conditions under which the pipeline diameter D is of a similar order of magnitude to the boundarylayer thickness δ i.e., δ/D ∼ O(1). Twodimensional ReynoldsAveraged NavierStokes (RANS) equations with shear stress transport (SST) kω turbulence closure were solved using a Petrov–Galerkin finite element method (PGFEM). The effects of the seabed roughness k_{s}/D and the KeuleganCarpenter number KC = U_{m}T/D on the hydrodynamic force coefficients were investigated, where k_{s} is the Nikuradse's equivalent roughness, T is the period of oscillatory flow and U_{m} is the amplitude of the oscillatory velocity. The diameter of the submarine pipeline is fixed at D = 0.1 m. The Reynolds number, defined as Re = U_{m}D/υ (where ν is the kinetic fluid viscosity), ranges from 1 × 10^{4} to 4.5 × 10^{4}. The numerical results show that the boundarylayer thickness increases with k_{s}. Hydrodynamic force coefficients are significantly affected by δ/D in the range of δ/D ∼ O(1), while δ/D depends on k_{s}/D and KC number. The negligence of velocity reductions in the wave boundary layer leads to overestimations of the submerged weight required for achieving onbottom stability.
Original language  English 

Pages (fromto)  114123 
Number of pages  10 
Journal  Coastal Engineering 
Volume  140 
DOIs  
Publication status  Published  1 Oct 2018 
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Projects
 2 Finished

Hydrodynamic Forces on Small Diameter Pipelines Laid on Natural Seabed
Cheng, L., Draper, S., An, H., Zhao, M., White, D. & Fogliani, N.
Australian Research Council, Woodside Energy Limited
1/01/15 → 30/06/20
Project: Research

Effect of natural seabed on hydrodynamics around cylindrical structures
1/01/15 → 11/01/18
Project: Research