This study adopts a multi-disciplinary optimization design method based on an approximation model to improve the comprehensive performance of axial-flow pump impellers and fully consider interaction mutual influences hydraulic structural designs. The lightweight research takes blade mass efficiency condition as objective functions head, efficiency, maximum stress value, deformation value under small flow constraints. In process, head remains unchanged or varies in range. Results show that...

To explore the structural dynamic characteristics of impeller and shaft system axial flow pump as turbine, variation law transient equivalent stress, deformation, mode are analyzed by fluid-structure interaction method. Findings indicate that stress is centralized at blade root around hub tends to decrease it moves towards shroud. The maximum 1.0Qbep 1.1Qbep 1.26 times 2.0 higher than 0.8Qbep. Blade deformation significantly influenced rate. 1.6 3.6 with prestress in dry has an average...

Axial-flow pumps may experience significant pressure pulsation and high hydraulic noise when deviating from design conditions, this article investigates the cross influence of rotational speed flow rate on inlet an axial-flow pump based coherence theory through physical model experiments. The energy amplitude is directly proportional to inversely rate, as increases, distribution blade passage frequency (fBPF) within different bands improves. Pressure overall natural device work together...

In order to explore the transient characteristics of large-scale vertical siphon axial flow pumping station during start-up and exhaust process, numerical simulations were carried out on process under two starting modes pre-opening vacuum breaking valve keeping closed. The calculation results show that phase unit, separation phenomenon impeller channel pump device with closed is serious, vortex in guide vane blocks channel, instantaneous impact blade surface strong. field pre-open failure...

A bi-directional pump is designed by using S-shaped hydrofoil, the most convenient way to achieve operation. In this paper, high-speed photography used visualize flow field characteristics of bidirectional under different cavitation numbers, and changes caused are quantitatively analyzed in combination with pressure pulsation sensor. The results show that operation efficiency reverse lower than forward Tip clearance occurs on both suction surfaces impeller large flow. operation, influence...

The S-shaped hydrofoil is often used in the design of reversible machinery due to its centrally symmetrical camber line. objective this paper study influence cloud cavitation on flow structure and unsteady characteristics lift drag around an via experimental tests numerical simulations. In component, were carried out a tunnel high-speed camera was record details with different numbers. results show that sheet gradually transforms into decrease inlet number, maximum cavity length increases...

Low-head vertical axial-flow pump as turbine (PAT) devices play a vital part in the development of clean energy for hydropower plain areas. The traditional method evaluating flow loss hydraulic machinery is calculated by pressure drop method, limitation which that location occurrence large losses cannot be accurately determined. In this paper, entropy production theory introduced to evaluate irreversible PAT from perspective second law thermodynamics. A three-dimensional model established...

Bidirectional axial flow pumps are of growing importance in flood control and irrigation. Reverse operation is a common concern during the bidirectional pumps. Therefore, this paper focuses on studying state discharge pipe pump operating reverse at various rates, utilizing model testing numerical simulation methods. Research shows that spiral leads to high head measurements. Moreover, generates vortices pipe, with greater vortex intensity range occurring lower causing poor velocity...

Axial flow pumps are widely used in ship jet propulsion units and coastal plain pumping stations. In the actual operation process, axial need to operate extreme working conditions, order explore safety stability of operating under special this paper adopts a method that combines model experiment numerical simulation. A full-condition pump section (AFPS) is carried out on high-precision system test platform. Meanwhile, simulation predicting full characteristics AFPS constructed. Numerical...

Inadequate blade angle adjustment or manufacturing errors will cause inconsistencies in the of an axial‐flow pump. In this study, hydrodynamic characteristics pump with inconsistent are investigated by analyzing hydraulic performance and pressure pulsation. The analysis is conducted performing a numerical simulation combined model test. Results show that, relative to case without deviation, deviation exhibits changes periodicity flow field impeller. Such result uneven impeller passage....

The use of existing large pumping station equipment for upstream residual water reverse power generation is an unrealized yet valuable renewable energy project. At present, some axial flow pump stations have begun to perform operations; however, related research has not started. In this paper, entropy theory applied a large-scale system in operations, and the method used investigate accurate size distribution mechanical dissipation each component under different conditions. First,...

Clarifying the evolutionary mechanism of start-up process a large axial-flow pump that includes cutoff facilities is great significance for ensuring safe and stable operation such system. However, three-dimensional dynamic characteristics prototype system (PAPS), considering facilities, are still unknown. In this paper, method combining motor starting characteristic experiment, computational fluid dynamics, field test proposed to study PAPS. The results indicate flow interruption will...

The continuous deterioration and development of tip leakage vortex (TLV) cavitation in the pump-jet propulsion significantly affect performance operational stability. Larger eddy simulation tunnel experiment are utilized to investigate temporal spatial evolution characteristics TLV under varying conditions. results reveal that prompts gradually move away from blade suction surface due increasing pressure difference at surface. Furthermore, amplifies effect radial outward Coriolis force makes...

Vortex breakdown in a pump sump is complex and negative factor for the pump. Different from my previous study that focused mainly on development process of vortex its damage to pump, this paper new perspective studies energy dissipation time–frequency characteristics induced by breakdown. The tested data pressure velocity were obtained model. Considering gas–liquid two-phase flow vortices, numerical simulation approach conducted verified. results show rules reveal initiated near blade....

The formation of an inlet vortex seriously restricts axial-flow pump device performance and poses a great threat to the safe stable operation entire system. In this study, change trends its influence on are investigated numerically experimentally in vertical device. Four groups fixed generators (VGs) installed front impeller create vortices at inlet. is qualitatively quantitatively analyzed. patterns different positions moments explored reveal shape trend pressure fluctuation induced by...

In order to study the evolution characteristics of suction-side-perpendicular cavitating vortex in an axial-flow pump under low flow conditions, model tests, high-speed imaging, and SST-CC turbulence were used simulate external cavitation morphology pump. The law (SSPCV) was revealed by turbulent kinetic energy, liutex identification, vorticity transport equation. results show that at number can be divided into three stages: generation, development, breaking stage. generation stage, velocity...

Pressure and vibration displacement value are relatively measured by 14 pressure sensors 2 distributing inside the tank-type model axial flow pump device under different rates. By comparison, it is found that pulsation on inlet of impeller main cause hydraulic induced device, to have similar amplitude trend with vertical as rates increases large correlation coefficient horizontal high through time-domain analysis. frequency-domain analysis, frequency three multiplies shaft frequency, but one...