In this network we have two special vertices: a source vertex s and a sink vertex t. Our goal is to send the maximum amount of flow from s to t; flow can only travel along arcs in the right direction, and is constrained by the arc capacities. This “flow” could be many things: imagine sending water along pipes, with the capacity representing the size of the pipe; or traffic, with the capacity be...

There have been many investigations of the stability of Hagen-Poiseuille flow in the 125 years since Osborne Reynolds' famous experiments on the transition to turbulence in a pipe, and yet the pipe problem remains the focus of attention of much research. Here, we discuss recent results from experimental and numerical investigations obtained in this new century. Progress has been made on three f...

In this paper we present a hybrid model for coupling of biofilm growth and hydrodynamic flow in a pipe. A cellular automata model, which is a discrete model, is used to describe the growth of biofilm. This stochastic discrete model is coupled with a continuum model of the fluid flow in a pipe. The potential applications of the proposed model are the flow in drinking water pipe systems or in aqu...

According to flexibility of pneumatic conveying systems with respect to other types of transmission systems, this system has wide application in industry and agriculture processes. One important application of this system is in the loading and unloading tankers and powdery bulk materials such as trucks carrying cement, plaster and sand. Conveying efficiency is associated with pressure, which in...

Abstract. If a fluid enters an axially rotating pipe, it receives a tangential component of velocity from the moving wall, and the flow pattern change according to the rotational speed. A flow relaminarization is set up by an increase in the rotational speed of the pipe. It will be shown that the tangentialand the axial velocity distribution adopt a quite universal shape in the case of fully de...

In this paper, a non-isothermal flow of a micropolar fluid in a thin pipe with circular cross-section is considered. The fluid in the pipe is cooled by the exterior medium and the heat exchange on the lateral part of the boundary is described by Newton’s cooling condition. Assuming that the hydrodynamic part of the system is provided, we seek for the micropolar effects on the heat flow using th...

A promising technique for the formal verification of embedded and cyber-physical systems is flow-pipe construction, which creates a sequence of regions covering all reachable states over time. Flow-pipe construction methods can check whether specifications are met for all states, rather than just testing using a finite and incomplete set of simulation traces. A fundamental challenge when using ...

In many urban areas of the developing world, piped water is supplied only intermittently, as valves direct water to different parts of the water distribution system at different times. The flow is transient, and may transition between free-surface and pressurized, resulting in complex dynamical features with important consequences for water suppliers and users. Here, we develop a computational ...

The present work describes the development of a pulsed photoacoustic (PA) flowmeter. An acoustic wave in a flowing fluid is produced by absorption of a laser pulse focused over a path flow line. The acoustic propagations, along and against the flow, are monitored by two cw probe beams. In the interaction, the probe beam undergoes a transient deflection that is detected by a fast response photod...

Measurements are given of the tiotal pressure and yaw relative to the pipe axis of flow in various pipe bends attached to the end of a long straight pipe, for a pipe Reynolds number of 2-36 x lo5. The behaviour of the induced secondary flows is presented in detail. In a 180" bend it is found that, from the start of tho bend, the secondary flows increase to a maximum and then decrease to a stead...