Visualizing test on the pass-through and collision characteristics of coarse particles in a double blade pump

Minggao Tan,Yichao Lian,Houlin Liu,Xianfang Wu,Rong Ding 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.1

As the key equipment in deep ocean mining, the slurry pump suffers from wear and blocking problems. In this paper, high-speed photography technique is applied to track the movement rule of single particle of the coarse particle solideliquid two-phase flow in a double blade slurry pump. The influences of particle diameter and particle density on the pass-through and collision characteristics of particles are analyzed as well. The results show that the average of the passing pump time first decreases and then increases when the particle diameter increases. The average of the passing pump time decreases by 22.7%, when the particle density increases from 1.09 g/cm3 to 1.75 g/cm3. Besides, the particle density has great influence on the location where the particle hits the tongue. Most particles of 1.09 g/cm3 hit the tongue on the left side, while collision location of particles of 1.75 g/cm3 is mainly on the top and at the right side of the tongue. The research can provide a basis for the optimization design of slurry pump in deep ocean mining system.

Visualizing test on the pass-through and collision characteristics of coarse particles in a double blade pump

Tan, Minggao,Lian, Yichao,Liu, Houlin,Wu, Xianfang,Ding, Rong The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.1

As the key equipment in deep ocean mining, the slurry pump suffers from wear and blocking problems. In this paper, high-speed photography technique is applied to track the movement rule of single particle of the coarse particle solid-liquid two-phase flow in a double blade slurry pump. The influences of particle diameter and particle density on the pass-through and collision characteristics of particles are analyzed as well. The results show that the average of the passing pump time first decreases and then increases when the particle diameter increases. The average of the passing pump time decreases by 22.7%, when the particle density increases from $1.09g/cm^3$ to $1.75g/cm^3$. Besides, the particle density has great influence on the location where the particle hits the tongue. Most particles of $1.09g/cm^3$ hit the tongue on the left side, while collision location of particles of $1.75g/cm^3$ is mainly on the top and at the right side of the tongue. The research can provide a basis for the optimization design of slurry pump in deep ocean mining system.

Multi-size Numerical Simulation of Bubbles on Gas-liquid Two-Phase Flow in a Centrifugal Pump

Tan Minggao,Tong Qin,Wu Xian-Fang,Shao Chen,Ma Haochen 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.4

In order to further understand the distribution and motion of gas phase in the gas-liquid two-phase flow inside a centrifugal pump, the numerical simulation on gas-liquid two-phase flow in the centrifugal pump was carried out and the CFD method was verified by experiment test. The MUSIG model was used as the multiphase flow model, coupled with the Prince-Blanch model and the Luo-Svendson model to describe the bubble breaking and coalescence process. The influence of inlet gas volume fraction and liquid flow rate on the gas-liquid two-phase flow inside centrifugal pump was investigated. The results show that the proportion of large bubbles in impeller is higher than that in volute. Large bubbles are mainly at the suction chamber inlet and impeller inlet, and small bubbles are mainly at the impeller outlet and volute outlet. From suction chamber, impeller to the volute, the average diameter of bubbles decreases in turn. With the increase of inlet gas volume fraction, the proportion of small bubbles in the pump decreases. Also, the flow pattern inside the pump gradually changes from bubble flow to gas pocket flow and the average diameter of bubbles in each flow passage component increases. With the increase of liquid flow rate, the proportion of small bubbles in the pump increases. Meanwhile, the flow pattern gradually changes from gas pocket flow to bubble flow and the average diameter of bubbles in each flow passage component decreases.

Magnetic Interconnected Macroporous Imprinted Foams for Selective Recognition and Adsorptive Removal of Phenolic Pollution from Water

Zhenjiang Tan,Minggao Tan,Jiangdong Dai,Wenna Ge,Wenjing Zhu,Yongsheng Yan 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

Here, novel magnetic imprinted porous foams (MIFs) were prepared by Pickering oil-in-water high internal phaseemulsion polymerization, using renewable cellulose nanocrystals (CNCs) derived from cotton source as the stabilizer, andsurfactant Tween 85 and iron oxide magnetic nanoparticles as additive in aqueous phase, for selective adsorption of 4-nitrophenol (4-NP). Interconnected porous foam structure was formed and optimized by controlling the addition amount ofsolid stabilizer CNCs, Tween 85, and oil phase volume, the optimum value of which was 7.5 wt%, 5.0 wt%, and 85 %,respectively. The as-synthesized imprinted material had the good thermal stability and magnetic responsivity. The adsorptionequilibrium data was fitted well by the Langmuir isothermal model with a maximum adsorption capacity of 287.5 μmol/g. Pseudo-second-order kinetics model could better describe the kinetics data. MIFs showed excellent selective ability for 4-NPas compared with these structural analogues. Besides, Thomas model explained the dynamic breakthrough curves better. Theregeneration ability of MIFs was also satisfying after several reuse.

Fluid-Structure Interaction Study on Diffuser Pump With a Two-Way Coupling Method

Xu, Huan,Liu, Houlin,Tan, Minggao,Cui, Jianbao Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.2

In order to study the effect of the fluid-structure interaction (FSI) on the simulation results, the external characteristics and internal flow features of a diffuser pump were analyzed with a two-way flow solid coupling method. And the static and dynamic structure analysis of the blade was also caculated with the FEA method. The steady flow field is based on Reynolds Averaged N-S equations with standard $k-{\varepsilon}$ turbulent model, the unsteady flow field is based on the large eddy simulation, and the structure response is based on elastic transient structural dynamic equation. The results showed that the effect of FSI on the head prediction based on CFD really exists. At the same radius, the van mises stress on the nodes closed shroud and hub was larger than other nodes. A large deformation region existed near inlet side at the middle of blades. The strength of impeller satisfied the strength requirement with static stress analysis based on the fourth strength theory. The dynamic stress varied periodically with the impeller rotating. It was also found that the fundamental frequency of the dynamic stress is the rotating frequency and its harmonic frequency. The frequency of maximum stress amplitude at node 1626 was 7 times of the rotating frequency. The frequency of maximum stress amplitude at node 2328 was 14 times of the rotating frequency. No matter strength failure or fatigue failure, the root of blades near shroud is the key region to analyse.

Effect of Discharge Elbow on Performance of the Axial Flow Pump in Saddle Zone

Xianfang Wu,Heyu Ye,Minggao Tan,Houlin Liu 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.4

The discharge elbow is an important part for the axial flow pump system, and the saddle area on the performance curve is a special characteristic of the axial flow pump. In order to reveal the influence of discharge elbow on the saddle zone, the saddle zone performance of an axial flow pump with two different discharge elbows (90° and 60°) is described in this paper by simulation and test. First, the effect of discharge elbows on pump energy performance is analyzed. The results indicate that the saddle zone of model pump with different discharge elbows is always between 0.5QBEP and 0.6QBEP (QBEP represents flow rate at the best efficient point), and the head value reaches the minimum at 0.55QBEP. Then, the analysis on pressure pulsation of different models is shown. The results show that compared to 90° discharge elbow model, the peak to peak value of pressure pulsation of 60° discharge elbow model at impeller inlet and pump outlet all reduces significantly under each flow rate. When the discharge elbow is 90°, the main frequency of the pressure pulsation at impeller inlet and pump outlet is the blade passing frequency fp, and many low-frequency pulsation components appear in saddle zone. When the discharge elbow is 60°, the main frequency of pressure pulsation at pump outlet changes from the blade passing frequency fp to the axial passing frequency fn. Finally, a focus by the numerical simulation about the internal characteristics is given. It is found that a small amount of vortex occurs in these two discharge elbows at saddle zone condition while the high speed area appears in pump outlet extend. After the 90° discharge elbow is replaced by 60° discharge elbow, the streamline distribution becomes more uniform and the hydraulic loss caused by the vortex decreases.

Performance of water-jet pump under acceleration

Wu Xian-Fang,Li Ming-Hui,Liu Houlin,Tan Minggao,Lu You-Dong 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1

The instantaneous acceleration affects the performance of the water-jet pump obviously. Here, based on the user-defined function, the method to simulate the inner flow in water-jet pumps under acceleration conditions was established. The effects of two different acceleration modes (linear acceleration and exponential acceleration) and three kinds of different acceleration time (0.5s, 1s and 2s) on the performance of the water-jet pump were analyzed. The results show that the thrust and the pressure pulsation under exponential acceleration are lower than that under linear acceleration at the same time; the vapor volume fraction in the impeller under linear acceleration is 27.3% higher than that under exponential acceleration. As the acceleration time increases, the thrust gradually increases and the pressure pulsation amplitude at the impeller inlet and outlet gradually decreases, while the law of pressure pulsation is the opposite at the diffuser outlet. The main frequency of pressure pulsation at the impeller outlet is different under different acceleration time. The research results can provide some reference for the optimal design of water-jet pumps.