A general "sound boundary" curve was developed which establishes the combinations of minimum flow Reynolds numbers and percent stenosis required for the onset of vascular murmurs. The curve was derived by a combination of engineering analysis and animal experiments in which thin circular orifice plates were implanted in the descending aortas of anesthetized dogs. The results indicate that the s...

We review wall-bounded turbulent flows, particularly high–Reynolds number, zero–pressure gradient boundary layers, and fully developed pipe and channel flows. It is apparent that the approach to an asymptotically high– Reynolds number state is slow, but at a sufficiently high Reynolds number the log law remains a fundamental part of the mean flow description. With regard to the coherent motions...

Transient laminar mixed convection in an asymmetrically and differentially heated vertical channel of finite length subject to an opposing buoyancy is investigated by solving the unsteady two-dimensional Navier–Stokes and energy equations. Results illustrate the effects of buoyancy strength or Richardson number Ri 1⁄4 Gr=Re and Reynolds number Re on the overall flow structure and the nondimensi...

Results are reported from a three-dimensional computational stability analysis of flow over a backward-facing step with an expansion ratio (outlet to inlet height) of 2 at Reynolds numbers between 450 and 1050. The analysis shows that the first absolute linear instability of the steady two-dimensional flow is a steady three-dimensional bifurcation at a critical Reynolds number of 748. The criti...

As technological advances allow us to fabricate smaller autonomous self-propelled devices, it is clear that at some point directed propulsion could not come from pre-specified deterministic periodic deformation of the swimmer's body and we need to develop strategies for extracting a net directed motion from a series of random transitions in the conformation space of the swimmer. We present a th...

A two-dimensional numerical investigation of the flow-induced vibration of a circular cylinder held free to oscillate transverse to the free-stream direction has been performed. The simulations were performed over a Reynolds number range Re= f30,200g and for an infinite reduced velocity. Two regions of high amplitude oscillations are observed and are referred to as the viscous and higher Reynol...

Floquet theory is used to describe the unstable spectrum at large scales of the βplane equation linearized about Rossby waves. Base flows consisting of one to three Rossby wave are considered analytically using continued fractions and the method of multiple scales, while base flow with more than three Rossby waves are studied numerically. It is demonstrated that the mechanism for instability ch...

Several authors have now suggested that some interstellar clouds above the plane of the Galaxy are interacting with the Reynolds’ layer, the warm ionized gas extending well above (H ∼= 910 pc) the Galactic plane (Reynolds 1993). Characterizing the interaction between these clouds and their surroundings should be useful in understanding one source of interstellar turbulence: vertical shear flows...

An experimental study is conducted on flow past a circular cylinder fitted with some tripping wires on its surface. The work investigates the dependency of the critical wire locations on the wire size and Reynolds numbers, and examines the wake and vortex shedding characteristics in an effort to advance the understanding of the critical wire effects beyond the existing literature. The primary a...

The results of a numerical study of the magnetic dynamo effect in cylindrical von Kármán plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity i.e., the fluid Reynolds number Re is comparable to the mag...