... pairs of stationary smooth cylinders of unequal diameters were tested in various tandem and staggered positions, all in the subcritical Reynolds number regime. The downstream cylinder in the wake experiences a drag reduction. When a larger cylinder is placed upstream, the drag coefficient...

...Lars C. Gansel; Thomas A. McClimans; Dag Myrhaug Experiments were carried out to measure forces on and wake characteristics downstream from fish cages. Cylinders made from metal mesh with porosities of 0%, 30%, 60%, 75%, 82%, and 90% were tested in a towing tank. The drag force was measured...

...Arash Zakeri Submarine landslides and debris flows are among the most destructive geohazards, economically and environmentally, for installations on the seafloor. Estimating the drag forces caused by these geohazards is an important design consideration in offshore engineering. A summary...

... mode response of the tether dominates the motion. Nonlinearity in the equation of motion is produced due to the relative velocity squared drag force. In order to trace different branches of the response curve and investigate different instability phenomena that may exist, an arc-length continuation...

... cylinders with a maximum Reynolds number of 77,000. The elastically supported downstream cylinder moves downward and inward toward the centerline of the upstream cylinder’s wake with increasing flow velocity, indicating the presence of a transverse lift force and reduced drag in the wake. These forces can...

...Arvid Naess; Oleg Gaidai The focus of the present paper is the extreme response statistics of drag dominated offshore structures subjected to harsh weather conditions. More specifically, severe sea states both with and without strong current are considered. The nature of the hydrodynamic forces...

...Oleg Gaidai; Arvid Naess Fatigue analysis for fixed offshore structures is an important practical issue. These structures are often drag dominated, which makes the deck response a non-Gaussian process when it is assumed that the irregular waves are Gaussian. Incorporating nonlinear and non-Gaussian...

... of the lines is studied for physical insight. Within this framework, the frequency domain equations are rigorously formulated, and the nonlinearities in the restoring forces and drag are statistically linearized. The model allows key coupling effects to be understood; among other things, the equations...

..., in addition to the importance of gravitational and inertial forces, the viscosity affects the drag hydrodynamic force, as well. It should be noted that viscosity and consequently drag coefficient in Froude type modeling cannot be quite applicable and this causes the difference observed between the results...

... to the effects of the mobile base, the various hydrodynamic forces exerted on these systems in an underwater environment are also incorporated into the simulation. The effects modeled in this work are added mass, viscous drag, fluid acceleration, and buoyancy forces. For drag forces, the emphasis here...

..., it was uncertain whether this type of scattering would be observed in the case of a single column, or whether it results from the transmission of wave modes trapped between the legs of a multiple column structure. In the case of a single column, if the diameter, D, is such that the flow lies within the drag...

...Robert D. Blevins, Consultant A model is developed for the steady fluid forces on a cylinder that is in the wake of a parallel, upstream cylinder in cross flow. The fluid forces are determined by correlating experimental data with an asymptotic model of the wake. This allows both lift and drag...

.... This paper describes the test setup, and measurement system for a series of fixed caisson tests and demonstrates the consistency of the test data. The measured inline drag and transverse lift forces on the fixed caisson at different drafts are presented and the effect of the fluid velocity and flow vorticity...

.... The analysis is performed in both model and full scales so that the difference in the results may be investigated. Also, since the model test data are available, comparisons are made between the CFD and model test results on the drag and lift forces on the caisson. The authors have the pleasure...

...Chih Young Liaw; Xiang Yuan Zheng Besides the commonly considered drag force, inundation due to variable water surface is another important nonlinear effect of wave loading. Quadratic and quartic approximations of the inundation drag force are derived using the least squares method. Other nonlinear...

... ˙ t + 1 2 ρ DC D | u t + U | u t + U in which the particle kinematics are computed by using the regular stream function theory of an appropriate order. The recommended values of the inertia coefficient C M = 1.70 , and drag coefficients...

...Mario Di Paola; Giuseppe Failla This study presents a new statistical cubicization approach for predicting the stochastic response of offshore platforms subjected to a Morison-type nonlinear drag loading. Statistics of the original system are obtained from an equivalent nonlinear system, which...

... coupled with surge, sway, heave, roll, pitch, and yaw motions of the hull. The linear frequency-dependent hydrodynamic response to the hull’s own motions accounted for memory effects that were approximated in the time domain by a finite state space model. The nonlinear hydrodynamic drag force acting...

... . Manuscript received by the OMAE Division, February 11, 2000; revised manuscript received November 27, 2000. Associate Editor: S. Calisal. 11 February 2000 27 November 2000 naval engineering load distribution drag Irrespective of the location of the floating production system...

...Matthew Lake; Haiping He; Armin W. Troesch; Marc Perlin; Krish P. Thiagarajan Research papers at previous OMAE conferences by Thiagarajan and Troesch 4 5 described forced oscillation model tests using a 0.45-m-dia cylinder and a 0.6-m-disk appended to the cylinder base for drag augmentation...