Bridge piers on river channels can cause obstacles for flood flow by reducing the cross-sectional area and inducing local eddy currents high velocities, which may destroy hydraulic structures. A two-dimensional numerical model was used to investigate effects of bridge hazards in Jialing River, China. For modeling, Mike 21 FM used, is an unstructured mesh finite volume that solves shallow water equations. The validated with collected historical traces, sensitivity analyses identified Manning...

Rapid global development has resulted in the widespread use of water pipelines industrial and agricultural production life. During transportation deployment, pipes with different angles need to be positioned according geographical topographical problems. Flowmaster simulation software was used simulate leakage process angles. The transient characteristics fluids pipeline were studied detail. influences parameters, such as bending coefficient R/D (R is turning radius pipe, D inner diameter...

Depending on the long-term hydraulic development of Francis turbine, blade channel vortex phenomenon was investigated systematically from design, experimental and numerical computation in this paper. The difference between high water head low turbine also analyzed. Meanwhile, relationship operating stability investigated. results show that is an intrinsic property for under small flow rate condition, turning-point inception curve appears at unit speed region, variation trend closely related...

<title>Abstract</title> Traditional dredging methods often have problems such as low accuracy, serious silt escape and siltation, high maintenance cost, limited use. The airlift system has the characteristics of simple structure, no mechanical moving parts, need to consider lubrication wear problems, work safety reliability, is suitable for river lake reservoir projects with environmental protection requirements large depth. In order further explore internal flow mechanism hydraulic air lift...

The gas-lift system has a lot of significant advantages in sewage treatment, deep well oil recovery, liquid metal cooled reactor and magnetohydrodynamic power converters. densities different media gas have great influences on the performance lift system. Therefore, based Fluent simulation software, using Euler model &lt;i&gt;k&lt;/i&gt;-&lt;i&gt;ω&lt;/i&gt; SST (shear stress transport) turbulence model, gas-liquid two-phase flow behaviors nitrogen-water, nitrogen-kerosene, nitrogen-mercury...

Water droplet impacting into a deep liquid pool is one of the most well-known flow phenomena in fluid mechanics. As ubiquitous natural aeration process, coalescence water droplets lakes and ponds subsequent bubble entrapment are notable ways gas-liquid exchange nature, it great significance for underwater sound transmission, aquatic ecosystems chemical process. The shape an oscillating impact under different surrounding medium initial condition key factor cavity formation entrapment. In this...

A pneumatic lifting pump is used in sewage treatment, offshore oil production, and other fields because of its simple structure strong practicability. In order to study internal hydraulic characteristics gas-liquid two-phase flow, this paper carries out experimental research on the influence different air intake modes riser diameters performance a pump. The air-water flow pattern motion bubble formation at nozzle are obtained by high-speed camera. Through theoretical analysis, model...

This paper presents numerical analysis of unsteady flow in a scroll hydraulic pump to discover its mechanism. The dynamic mesh model has be used simulate the field unsteadily. patterns and pressure distributions suction, squeezing discharge chamber are analysed. suction process continues until crank angle reaches 320 degree. Then rises instantaneously, fluid begins out from chamber. Because high difference at clearance, jet vortex appear, large losses generates with them. In addition,...

In the present paper, computer fluid dynamics(CFD) with dynamic mesh model had been applied in scroll hydraulic pump to obtain its flow field at different leakage clearance. The force on orbiting scroll, mass rate and efficiency clearance were calculated based data. results indicated that when increased from 0.5mm 1.5mm, average pressure, maximum of pressure fluctuation, jet velocity, shaft power, cavitation degree decreased increased. If was 2.0mm, high discharge flowed through led increase...

The gas-lift pump has been adopted to enhance the natural circulation capability in type of lead-bismuth alloy cooled reactors such as ADS and LMFR. ability system safety are obviously influenced by two phase flow characteristics liquid metal-inert gas. In this study, numerical research performed evaluate with pump. drift theory, void fraction prediction model friction pressure drop have simulation. effects gas rate, bubble diameter height ascension pipe on analyzed. results showed that...

In the hydraulically suspended passive shutdown assembly, in order to prevent liquid suspension rod falling too fast and outer tube from violent impact, it is necessary study way increase flow resistance. This added grooves wall of narrow channel its Using RNG k-ε turbulence model Fluent, influence groove structure parameters Reynolds number on resistance was discussed find optimal parameters. The results showed that increased with concave–convex ratio, when ratio small, decreased thickness,...

Traditional dredging methods often have problems such as low accuracy, serious silt escape and siltation, high maintenance cost, limited use. The pneumatic lifting system has the characteristics of simple structure, no mechanical moving parts, need to consider lubrication wear problems, work safety reliability, is suitable for river lake reservoir projects with environmental protection requirements large depth. In order further explore internal flow mechanism hydraulic system, in this...

Abstract In order to study the influence of bubble size and distance on interaction between bubbles, this paper discussed rising movement characteristics triple bubbles in static water based Fluent software. By analyzing track, flow fields velocity results show that, when diameters are 4mm, left middle is smaller than minimum coalescence distance, they coalesce. When 6mm, track small at bottom will be affected by wake big as rises, but do not 2mm, both sides attracted coalesce; there almost...

Abstract Pneumatic lifting pump, as one of the ideal new methods for mining and upgrading, has obvious advantages such simple structure, safety reliability. The research it important scientific value engineering significance. Based on Fluent simulation software, using Euler model SST k-ω turbulence model, with help UDF self-programming, influence variable air volumes-linear opening, linearly closing hydraulic characteristics air-water pump is discussed. results are shown follows. 1) In slow...