We consider the propagation of hydromagnetic waves generated by a compact turbulent source in low ionized plasmas, applying the Lighthill theory. We assume the plasma to be isothermal, and adopt a uniform, stationary medium thread by ordered magnetic fields as an initial condition. Then, the distinct properties of the hydromagnetic waves originating from a source oscillating with a fixed freque...

Compared with other modes of locomotion, swimming is energetically inexpensive. The costs of moving a unit mass of swimming animal are lower than for animal flight or terrestrial locomotion, but higher than those of human-engineered vehicles (SchmidtNielsen, 1972). To understand why, the efficiencies of the underlying processes that convert metabolic energy into mechanical power need to be dete...

We develop backstepping state feedback control to stabilize a moving shockwave in freeway segment under bilateral boundary actuations of traffic flow. A shockwave, consisting light upstream the and heavy downstream, is usually caused by changes local road situations. The density discontinuity travels drivers caught experience transitions from free congested traffic. Boundary design this paper b...

Although there are a number of papers on how fish swim (Gray, 1957; Aleev, 1969; Lighthill, 1969), we have been unable to find any measurements of the pressure on the body surface measured while a fish is swimming. A preliminary calculation using the Pitot equation indicated that the pressure against the anterior surface of the fish, expressed in centimetres of water, would be approximately equ...

This paper presents a novel dynamic model of a bio-inspired robotic fish underwater vehicle by unifying conventional rigid body dynamics and bio-fluid-dynamics of a carangiform fish swimming given by Lighthill’s (LH) slender body theory. It proposes an inclusive mathematical design for better control and energy efficient path travel for the robotic fish. The system is modeled as an 2-link robot...

The basic element of Lighthill's "sandwich model" of tropical cyclones is the existence of "ocean spray," a layer intermediate between air and sea made up of a cloud of droplets that can be viewed as a "third fluid." We propose a mathematical model of the flow in the ocean spray based on a semiempirical turbulence theory and demonstrate that the availability of the ocean spray over the waves in...

Practically our entire understanding of large-scale atmosphere–ocean dynamics depends on the notions of balance and potential-vorticity inversion. These are essential, for instance, for a clear understanding of the basic Rossby-wave propagation mechanism, or quasi-elasticity, that underlies almost every large-scale fluid-dynamical phenomenon of meteorological and oceanographical interest, from ...

l'rlnted ln (:reat Bratam Emendations to a proof in the general three-dimensional theory of oscilla,ting sources of waves Asymptotic forms far from the source region of waves generated by oscillating sources in a linear homogeneous anisotropic system were derived by a method of proof that requires emendation although the final conclusions remain unchanged. An intermediate asymptotic result. in ...