In this work, we focus on two-dimensional, incompressible viscous channel flow over an infinitely long cylinder and examine the effect of controlled rotational cylinder oscillation in reducing the drag exerted on the cylinder. Based on an analysis of the open-loop simulations, a control system is designed that automatically determines the frequency of cylinder oscillation, based on the Reynolds...

Experiments are conducted in a shock tube to study the shock loading of a cylinder and a cylinder bank. The experiments model the loading of the cooling tubes in an inertial confinement fusion reactor where banks of tubes line the reaction chamber. The diffraction of the shock wave is visualized using shadowgraphy. Shock loading of the cylinder(s) is measured with flush mounted piezoelectric pr...

We present an experimental study of the motion of a viscoelastic micellar fluid around a moving cylinder, which ranges from fluidlike flow to solidlike tearing and fracture, depending on the cylinder radius and velocity. The observation of crack propagation driven by the cylinder indicates an extremely low tear strength, approximately equal to the steady state surface tension of the fluid. At t...

Vortex formation from a horizontal cylinder coincident with a free surface of a shallow water flow having a depth of 25.4 mm was experimentally investigated using the particle image velocimetry technique. Instantaneous and time-averaged flow patterns in the wake region of the cylinder were examined for three different cylinder diameter values under the fully developed turbulent boundary layer c...

We consider the effective motion along a cylinder of a particle that freely diffuses in the bulk and intermittently binds to the cylinder. From an exact approach we derive the different regimes of the effective motion along the cylinder characterized by physical rates for binding/unbinding and the bulk diffusivity. We obtain a transient regime of superdiffusion and, interestingly, a saturation ...

6 In this paper, theoretical study is carried out to investigate the general 3D short-crested 7 wave interaction with a concentric two-cylinder system. The interior cylinder is imperme8 able and the exterior cylinder is thin in thickness and porous to protect the interior cylinder. 9 Both cylinders are surface-piercing and bottom mounted. Analytical solution is derived 10 based on the linear po...

We study the optimal packing of hard spheres in an infinitely long cylinder, using simulated annealing, and compare our results with the analogous problem of packing disks on the unrolled surface of a cylinder. The densest structures are described and tabulated in detail up to D/d=2.873 (ratio of cylinder and sphere diameters). This extends previous computations into the range of structures whi...

Under conditions of lean fueling or high exhaust gas recirculation, interactions between residual cylinder gas and freshly injected fuel and air produce undesirable combustion instabilities in spark-ignition engines. The resulting dynamics can be described as noisy bifurcations of a nonlinear map and are complicated by cylinder-to-cylinder coupling. We discuss the key dynamic features relevant ...

The present paper describes dynamic modelling, results of simulation and experimental investigation of a hydraulic stepper cylinder, which find application in manipulators and robots. The method of bond graph is used for modelling of the dynamics of the considered cylinder design. First, an initial digital simulation is performed in order to calculate basic dynamic characteristics of the cylind...

Experiments were conducted to obtain the modal damping ratios of two hollow cylinders of different thicknesses of Aluminum. An electro dynamic exciter with slip table is used to excite the hollow cylinders. The hollow cylinder (unit under test) is fastened to the exciter. The exciter is placed in the horizontal direction and connected to the slip table. A control accelerometer is placed at the ...