Numerical Simulation and Performance Prediction for Hydraulic Performance of Mine Drainage Pump

2013 ◽  
Vol 281 ◽  
pp. 216-220
Author(s):  
Bao Liang Li ◽  
Zhi Shun Yan ◽  
Xiao Wei Hu

By using the CFX technology in ANSYS Workbench, based on the different operation conditions, the numerical simulation of three dimension steady turbulent flow is carried on the D type mine drainage pump. The pump includes first impeller and guide vane, secondary impeller and guide vane, inlet, outlet. The results will reveals the distribution law of flow field and static pressure, and it further forecasts the performance curve of the multistage pump by means of choosing standard model and setting frozen interface. This method can provide certain theory basis for the energy saving work of the multistage pump.

Author(s):  
Hongjuan Ran ◽  
Xianwu Luo ◽  
Yao Zhang ◽  
Baotang Zhuang ◽  
Hongyuan Xu

The unsteady flow in a high-head pump-turbine whose head-discharge curve has the positive slopes at high-partial-load operation condition was investigated. It is noted that the numerical methods is very important for predicting this kind of head-discharge curve with positive slopes, and better agreement between calculation results and experimental data was achieved by using Spalart-Allmaras turbulence model and mesh strategy with y+ controlling for numerical simulation. From the analysis of hydraulic losses at different parts in the pump turbine, it is found that the head loss at the flow passage of the guide vane and stay vane was not small at pump mode. In order to make clear the reason why the positive slopes at head-discharge curve occur, the flow between the impeller exit and the inlet of spiral casing was checked carefully. Much intensive vortex was observed near the impeller shroud, and there was strong rotor stator interaction for those operation conditions with positive slope. It is suspected the instability such as positive slope at head-discharge curve was resulted from the vortex formation near the flow channel wall. Based on the flow analysis, the runner optimization was conducted so as to mitigate the intensive rotor stator interaction. It is noted that the pressure fluctuation as well as the flow pattern was improved by applying the optimized impeller.


2014 ◽  
Vol 532 ◽  
pp. 447-451
Author(s):  
Li Sheng Zhang ◽  
Jin Jiang ◽  
Zhi Huai Xiao ◽  
Yan Hui Li

In this paper, the relationship between impeller design parameters and performance of a partial emission pump is studied by numerical simulation. Nine straight radial impellers with different blade ratio γ (short blade length to long blade length ratio, γ=50%, 70% and 90%) and different front inclination angle β (β=8, 12 and 16 degree) were designed, while the rest geometric parameters of the pump were kept unchanged. All the numerical simulations were carried out by using the commercial software FLUENT V12.1 based on the Realizable k-ε turbulent model. The results showed that with increasing of front inclination angle, the capacity-head curve drops, the maximum head all appears at blade ratio γ=90%. The static pressure increases with increasing radius. A separation bubble can be observed at the outlet of diffuser tube.


2014 ◽  
Vol 1070-1072 ◽  
pp. 1937-1940
Author(s):  
Ling Zhang ◽  
Peng Jie Huang ◽  
Hai Qiang Li ◽  
Yun Peng Diao

Based on the three-dimensional Reynolds-Averaged N-S equations and the standard k-ε turbulence model, the inner flow of a multistage vane water centrifugal pump was simulated. The distribution law of inner flow was analyzed by using the SIMPLEC algorithm and multiple reference frame (MRF) model provided by CFD software Fluent. The pressure and velocity distribution law in impeller and vane diffuser are obtained. Results indicated that the lowest pressure area , where cavitation was easy to occur, was in the inlet of the first impeller blade back. There is reverse flow in outlet of impeller. An area of low pressure can be seen in the inlet of return guide vanes. The guide vane could reduce fluid velocity and eliminated fluid rotating component.


2013 ◽  
Vol 791-793 ◽  
pp. 550-553 ◽  
Author(s):  
Dong Dong Han ◽  
Cheng Jun Wang ◽  
Juan Chang ◽  
Lei Chen ◽  
Huai Bei Xie

At present, pulley produced in China has been able to meet the demand of domestic and international markets. But there are many problem of the pulley industry in our country, such as too many production enterprises and the low level of export products. And as components of drive system are light weight and raw material price of pulley casting are rising, manufacturing requirements of the pulley are also more and more high. Aiming at the casting defects of pulley that enterprise current product, pulley casting blank model of common material HT250 be made by three-dimension software, numerical simulation of filling and solidification process for pulley sand casting by the casting simulation software Procast, the size and location of the various casting defects were forecasted and analyzed, reflecting the pulley filling and solidification process of the actual situation, due to the thicker pulley rim and less heat dissipation, position of shrinkage is close to the middle of rim [, a method of eliminating defects is proposed to realize sequential solidification, and thus to minimize porosity shrinkage and improve casting performance and reduce casting time and reduce production costs.


Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 346 ◽  
Author(s):  
Lili Shen ◽  
Ning Wu ◽  
Gaizhen Yan

By using through-silicon-vias (TSV), three dimension integration technology can stack large memory on the top of cores as a last-level on-chip cache (LLC) to reduce off-chip memory access and enhance system performance. However, the integration of more on-chip caches increases chip power density, which might lead to temperature-related issues in power consumption, reliability, cooling cost, and performance. An effective thermal management scheme is required to ensure the performance and reliability of the system. In this study, a fuzzy-based thermal management scheme (FBTM) is proposed that simultaneously considers cores and stacked caches. The proposed method combines a dynamic cache reconfiguration scheme with a fuzzy-based control policy in a temperature-aware manner. The dynamic cache reconfiguration scheme determines the size of the cache for the processor core according to the application that reaches a substantial amount of power consumption savings. The fuzzy-based control policy is used to change the frequency level of the processor core based on dynamic cache reconfiguration, a process which can further improve the system performance. Experiments show that, compared with other thermal management schemes, the proposed FBTM can achieve, on average, 3 degrees of reduction in temperature and a 41% reduction of leakage energy.


2016 ◽  
Vol 8 (10) ◽  
pp. 168781401667375 ◽  
Author(s):  
Wei Li ◽  
Xiaoping Jiang ◽  
Qinglong Pang ◽  
Ling Zhou ◽  
Wei Wang

Author(s):  
R B Anand ◽  
L Rai ◽  
S N Singh

The effect of the turning angle on the flow and performance characteristics of long S-shaped circular diffusers (length-inlet diameter ratio, L/Di = 11:4) having an area ratio of 1.9 and centre-line length of 600 mm has been established. The experiments are carried out for three S-shaped circular diffusers having angles of turn of 15°/15°, 22.5°/22.5° and 30°/30°. Velocity, static pressure and total pressure distributions at different planes along the length of the diffusers are measured using a five-hole impact probe. The turbulence intensity distribution at the same planes is also measured using a normal hot-wire probe. The static pressure recovery coefficients for 15°/15°, 22.5°/22.5° and 30°/30° diffusers are evaluated as 0.45, 0.40 and 0.35 respectively, whereas the ideal static pressure recovery coefficient is 0.72. The low performance is attributed to the generation of secondary flows due to geometrical curvature and additional losses as a result of the high surface roughness (~0.5 mm) of the diffusers. The pressure recovery coefficient of these circular test diffusers is comparatively lower than that of an S-shaped rectangular diffuser of nearly the same area ratio, even with a larger turning angle (90°/90°), i.e. 0.53. The total pressure loss coefficient for all the diffusers is nearly the same and seems to be independent of the angle of turn. The flow distribution is more uniform at the exit for the higher angle of turn diffusers.


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