this study proposed a new discharge estimation method using a mean velocity formula derived from chiu’s 2d velocity formula of probabilistic entropy concept and the river bed shear stress of channel. in particular, we could calculate the mean velocity, which is hardly measurable in flooding natural rivers, in consideration of several factors reflecting basic hydraulic characteristics such as r...

We use a numerical method that was described in Part 1 (Marcus 1984a) to solve the time-dependent Navier-Stokes equation and boundary conditions that govern Taylor-Couette flow. We compute several stable axisymmetric Taylor-vortex equilibria and several stable non-axisymmetric wavy-vortex flows that correspond to one travelling wave. For each flow we compute the energy, angular momentum, torque...

In a porous material, both the pressure drop across a bubble and its speed are nonlinear functions of the fluid velocity. Nonlinear dynamics of bubbles in turn affect the macroscopic hydraulic conductivity, and thus the fluid velocity. We treat a porous medium as a network of tubes and combine critical path analysis with pore-scale results to predict the effects of bubble dynamics on the macros...

In this article, turbulent flow heat transfer in the air gap between rotor and stator of a generator under nonhomogeneous heat flux is studied experimentally. The rotor consists of four symmetrical triangular grooves. The stator surface is smooth and does not include any grooves. The relative heat flux between the rotor and the stator is 1 to 3. Temperature and heat flux are measured locally at...

Spacers are used in spiral wound and plate and frame membrane modules to create flow channels between adjacent membrane layers and mix fluid within the flow channel. Flow through the spacer has a significant beneficial impact on mixing and resulting mass transfer rates but is accompanied by an undesirable increase in pressure drop. Computational Fluid Dynamics (CFD) is a common tool used to eva...

Graphene has attracted considerable attention due to its characteristics as a 2D material and its fascinating properties, providing a potential building block for nanofabrication. In nanochannels the solid-liquid interface plays a non-negligible role in determining the fluid dynamics. Therefore, for an optimal design of nanofluidic devices, a comprehensive understanding of the slippage in a wat...

Echocardiography is considered as the procedure of choice for the evaluation of cardiac performance and to gather other critical information both in the pre, intra and postoperative phases. Also, echo-Doppler-based methods can be used to calculate the flow velocity and volume and hence systemic blood flow. Unfortunately, due to intrinsic nature, echocardiog‐ raphy cannot be considered a bedside...

This paper focuses on simulations of enclosed air pocket movements in conjunction with bottom outlet operations. The critical velocity of water for air pocket transport in pipe is the minimal flow velocity for the air pocket start to move downstream. A numerical model is developed to simulate the critical velocity of air pocket transport in pipe flow and to discuss the impacts of tunnel slope, ...

Superfluid flow is a manifestation of quantum mechanics at the macroscopic level. Phenomena like dissipationless flow and persistent currents can be traced back to the existence of a macroscopic wavefunction. The gradient of its phase gives the superfluid velocity. However, superfluid flow is only stable below a critical velocity. Above this velocity, excitations of the fluid can be generated, ...

For the study of transients in gas-liquid flows, the equations of the so-called separated flow model are inadequate, because they possess, in the general case where gas and liquid move at different velocities, complex characteristics. This paper is concerned with the equations of motion for bubbly flow. The equations are discussed with emphasis on the aspects of relative motion and the characte...