We present the design of a novel compliant quadruped robot: Cheetahcub, and a series of locomotion experiments with fast trotting gaits. The robot’s leg configuration is based on a spring-loaded, pantograph mechanism with multiple segments. A dedicated open loop locomotion controller was derived and implemented. Experiments were run in simulation and in hardware on flat terrain and with a step-...

We consider the nature of non-linear flow of a two-layer fluid with a rigid lid over a long obstacle, such that the flow may be assumed to be hydrostatic. Such flows can generate hydraulic jumps upstream, and the model uses a new model of internal hydraulic jumps, which results in corrections to flows that have been computed using earlier models of jumps that are now known to be incorrect. The ...

The problem of steady subcritical free surface flow past a submerged inclined step is considered. The asymptotic limit of small Froude number is treated, with particular emphasis on the effect that changing the angle of the step face has on the surface waves. As demonstrated by Chapman & Vanden-Broeck, (2006) Exponential asymptotics and gravity waves. J. Fluid Mech. 567, 299–326, the divergence...

in order to increase the efficiency of the conveyance of the granular solids, a new experimental set-up is designed. the test rig has longitudinal trapezoidal slots in its conveying pipes. through experimentation, a correlation for friction factor in terms of solid mass flow rate, fluid flow rate and froude number is presented. it is shown that the mixture friction factor for pipes with inner t...

During walking, variability in step parameters allows the body to adapt to changes in substrate or unexpected perturbations that may occur as the feet interface with the environment. Despite a rich literature describing biomechanical variability in step parameters, there are as yet no studies that consider variability at the body-environment interface. Here, we used pedobarographic statistical ...

Failures of barrages or regulators or parts of them may be expected when excessive scour patterns are observed downstream of such structures. Severe and excessive scour may be largely due to unsymmetric operation of gates especially when a multi-vents barrages or regulator is being considered. Previous investigations proved that the scour patterns downstream hydraulic structures are functions o...

This paper considers the large-scale dynamics generated in the upper atmosphere by the destabilization of a linear internal gravity wave and its eventual restabilization through nonlinear processes into a coherent pattern. The assumption of a strongly dissipative medium is relevant to wave propagation in the thermosphere range above 100 km. A parametric instability analysis is carried out invol...

(i) For laminar flow (1) has been derived in [7] for f = −H ′′. A first analysis of that case is in [6]. Moreover this equation is also considered in the context of shock profiles in plasmas [2]. (ii) For turbulent flow in a certain distinguished limit concerning the Reynolds number and the Froude number eq. (1) has been derived in [3,4] with f = H . A multiple scales analysis of the full flow ...