Physical Model Test of Water Intake Including Huge Pump Station and Drum Screen

2008 ◽  
Author(s):  
Sadegh Barzegar ◽  
Mohammad Banae ◽  
Mohammad Ali Hamed ◽  
Mohammad Qaheri Badr
Keyword(s):  
Physical Model ◽  
Water Intake ◽  
Reverse Flow ◽  
Flow Behavior ◽  
Cross Flow ◽  
Air Entrainment ◽  
Physical Model Test ◽  
Original Design ◽  
Low Velocity ◽  
Pump Station

A physical model, built at an undistorted scale of 1:15 tested the original design of the six drum screen and nineteen cooling water pump intake connected to header bay. The capacity of origin water intake including huge pump station and drum screen is 400,000 m3/hr. The study objectives were to evaluate as-designed screen bay and pump bay performance and to propose design modifications to optimize intake flow conditions with respect to head-losses, uniformity of the approach flow, evenness of pump throat velocity distribution, and free and subsurface vortex formation. The model was built and operated in accordance with froude-number similitude. It allowed accurate representation of complex flow patterns caused by the physical geometry of the approach bay and pump bays. The major factors that can affect the selection of a concept and design development for a water intake are: a) The occurrence of dead water zones, flow separation or reverse flow b) Vortex building and air entrainment in the pump compartments c) Submerged vortices building in the pump compartments d) Low velocity area e) Strong rotational flow f) Strong cross flow appear in front of pump units g) Pre rotation in the pump suction lines. Dye injection was used to examine the stratified flow behavior along water. The existing design of the pump bays was found to produce a uniform, symmetrical flow distribution in the approach flow, weak but persistent floor and side-wall-attached submerged vortices, avoiding cross flow and reverse flow in front of the pumps and negligible swirling motion in the pump suction. Modified design includes (i) profiling low velocity area (ii) adding flow deflectors along inner walls (iii) infill area of low velocity (iv) adding suspended baffle in front of drum screens (v) adding diffuser block in front of pumps (vi) provision of floating booms in front of pumps.

Hydraulic Model and Numerical Simulation Study of Shuangwangcheng Pump Station

2011 ◽  
Vol 117-119 ◽  
pp. 647-651
Author(s):  
Chuan Qi Li ◽  
Wei Wang ◽  
Jie Gong ◽  
Xin Lai Zhao
Keyword(s):  
Numerical Simulation ◽  
Physical Model ◽  
Model Test ◽  
Hydraulic Model ◽  
Physical Model Test ◽  
Flow Conditions ◽  
Scheme Design ◽  
Model Studies ◽  
Pump Station ◽  
Good Agreement

Physical and numerical model studies were performed in order to study the flow conditions for the proposed pump station of Shuangwangcheng reservoir, Shouguang Ctiy. The flow velocity and the pressure distribution in the bidirectional culvert of Shuangwangcheng Pump Station had been obtained by hydraulic model test and numerical simulation. The physical model was constructed to a Froude scale of 1:20. A general conclusion was that, the computed results were good agreement with the data measured in physical model, and could be good complement for physical model test. Furthermore, negative pressure existing in discharge steep culvert in the initial scheme design was eliminated by moving the culvert controlling gate to the end of culvert in the modified scheme, and the flow conditions was improved.

Physical Model Study of Chicago's New Calumet Influent Pumping Station

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
D. Brocard ◽  
M. Garcia ◽  
T. Kunetz ◽  
J. Sobanski ◽  
A. Waratuke ◽  
...  
Keyword(s):  
Physical Model ◽  
Air Entrainment ◽  
Design Guidelines ◽  
Water Levels ◽  
Maintenance Cost ◽  
Optimized Design ◽  
Original Design ◽  
Pumping Station ◽  
Model Study ◽  
Wide Range

A new raw wastewater influent pumping station was designed for the Calumet Water Reclamation Plant in Chicago. The new station could not be designed to be in full compliance with design guidelines of the Hydraulic Institute due to site constraints. Proper operation of the pumping station and optimum operational flexibility are goals for the successful long term performance of the new station. A physical model study was used to identify deficiencies in the original design relative to flow characteristics. The model enabled development of design modifications to address hydraulic flow deficiencies. The optimized design resulted in pump approach flow conditions that provide proper pump performance under a wide range of varying water levels and different combinations of operating pumps and screen channels. Other benefits of the model included improvement in pump efficiency, lack of air entrainment, decreased pump wear, and decreased scour of concrete surfaces. Optimized design also results in operation and maintenance cost savings which, in the long run, will greatly surpass the cost of the physical model study. The required elements to optimize the performance were integrated with the design of the facility, thereby avoiding potentially costly retrofits if the deficiencies had not been mitigated prior to construction.

scholarly journals Reduction of Entrained Vortices in Submersible Pump Suction Lines Using Numerical Simulations

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6136
Author(s):  
Virgel M. Arocena ◽  
Binoe E. Abuan ◽  
Joseph Gerard T. Reyes ◽  
Paul L. Rodgers ◽  
Louis Angelo M. Danao
Keyword(s):  
Numerical Simulations ◽  
Physical Model ◽  
Model Test ◽  
Vortex Formation ◽  
Cross Flow ◽  
Structure Design ◽  
Physical Models ◽  
Physical Model Test ◽  
Design Modification ◽  
The Cross

Pump intake structure design is one area where physical models still remain as the only acceptable method that can provide reliable engineering results. Ensuring the amount of turbulence, entrained air vortices, and swirl are kept within acceptable limits requires site-specific, expensive, and time-consuming physical model studies. This study aims to investigate the viability of Computational Fluid Dynamics (CFD) as an alternative tool for pump intake design thus reducing the need for extensive physical experiments. In this study, a transient multiphase simulation of a 530 mm wide rectangular intake sump housing a 116 m3/h pump is presented. The flow conditions, vortex formation and inlet swirl are compared to an existing 1:10 reduced scaled physical model test. For the baseline test, the predicted surface and submerged vortices agreed well with those observed in the physical model. Both the physical model test and the numerical model showed that the initial geometry of the pump sump is unacceptable as per ANSI/HI 9.8 criteria. Strong type 2 to type 3 submerged vortices were observed at the floor of the pump and behind the pump. Consequently, numerical simulations of proposed sump design modification are further investigated. Two CFD models with different fillet-splitter designs are evaluated and compared based on the vortex formation and swirl. In the study, it was seen that a trident-shaped splitter design was able to prevent flow separation and vortex suppression as compared to a cross-baffle design based on ANSI/HI 9.8. CFD results for the cross-baffle design showed that backwall and floor vortices were still present and additional turbulence was observed due to the cross-flow caused by the geometry. Conversely, CFD results for the trident-shaped fillet-splitter design showed stable flow and minimized the floor and wall vortices previously observed in the first two models.

scholarly journals Determining the Depth of Local Scouring in a Downstream Energy Dissipation in the Physical Model Test

2021 ◽  
Vol 930 (1) ◽  
pp. 012022
Author(s):  
R D Lufira’ ◽  
S Marsudi ◽  
S Agustien ◽  
A Khosin
Keyword(s):  
Energy Dissipation ◽  
Physical Model ◽  
Model Test ◽  
Design Model ◽  
Physical Model Test ◽  
Original Design ◽  
Physical Model Tests ◽  
Final Design ◽  
Concrete Blocks ◽  
River Bottom

Abstract Karangnongko Weir is planned to be located in the Bengawan Solo River (Lower Solo River Basin) about 15 km downstream of the confluence of Bengawan Solo River with the Madiun River in Ngelo Village, Margomulyo Sub-District, Bojonegoro Regency, and Ngrawoh Village in Kradenan Sub-District, Blora Regency. This study aims to determine the Depth and pattern of scouring in downstream energy dissipation through physical model tests based on initial planning. Downstream protection of energy dissipation in the original design model combines 50 m of riprap rocks and 50 m of riprap concrete for a total length of 100 m of protection. The maximum scouring pattern occurred at elevation + 17.64 m, where the scouring was 4.36 m deep, from the planned essential height of Height 00 m. Thus, the downstream protection of energy dissipation was extended to 112 m in riprap concrete blocks for the final design model. Scouring at the end of riprap was 3.04 m, the original elevation of the river bottom of + 22.00 m, down to + 18.96 m. It is concluded that the protection is effective in reducing scouring by up to 30.27%.

scholarly journals Experimental Study on Flow Behavior of Unshrouded Impeller Centrifugal Pumps under Inlet Air Entrainment Condition

2021 ◽  
Vol 6 (3) ◽  
pp. 31
Author(s):  
Minquan Liao ◽  
Qiaorui Si ◽  
Meng Fan ◽  
Peng Wang ◽  
Zhonghai Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Pressure Pulsation ◽  
Reverse Flow ◽  
Flow Behavior ◽  
Air Entrainment ◽  
Pulsation Frequency ◽  
Centrifugal Pumps ◽  
Local Flow ◽  
Void Fractions ◽  
Starting Point

Results on overall pump head and efficiency performance, pressure pulsation and high speed camera visualization of flow patterns behavior are presented for different inlet air-water void fractions at a given rotational speed. With the increase of inlet void fractions and decrease of the flow rates, the size of bubbles increase and tend to agglomerate in specific impeller passage locations along the blade chord. The starting point of pump breakdown is related to a strong inward reverse flow occurring in a specific location near the shroud gap of the impeller and volute tongue region. Using a constant air void fraction value of 2%, pressure pulsation frequency results are analyzed in relation with local flow mixture patterns and flow rate modification.

Numerical Analysis on the CO-NO Formation Production near Burner Throat in Swirling Flow Combustion System

2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd Jaafar
Keyword(s):  
Swirling Flow ◽  
Reverse Flow ◽  
Flow Behavior ◽  
Recirculation Region ◽  
Mixing Enhancement ◽  
Ansys Fluent ◽  
Pressure Losses ◽  
No Formation ◽  
Swirl Angle ◽  
Air Mixing

The main purpose of this paper is to study the Computational Fluid Dynamics (CFD) prediction on CO-NO formation production inside the combustor close to burner throat while varying the swirl angle of the radial swirler. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore, designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion with low pressure losses. A liquid fuel burner system with different radial air swirler with 280 mm inside diameter combustor of 1000 mm length has been investigated. Analysis were carried out using four different radial air swirlers having 30°, 40°, 50° and 60° vane angles. The flow behavior was investigated numerically using CFD solver Ansys Fluent. This study has provided characteristic insight into the formation and production of CO and pollutant NO inside the combustion chamber. Results show that the swirling action is augmented with the increase in the swirl angle, which leads to increase in the center core reverse flow, therefore reducing the CO and pollutant NO formation. The outcome of this work will help in finding out the optimum swirling angle which will lead to less emission.  

Model Test Study on Influences of Layered Rock Mass Dip Angle on Stability of Deep-Buried Tunnel

2011 ◽  
Vol 90-93 ◽  
pp. 2363-2371
Author(s):  
Bin Wei Xia ◽  
Ke Hu ◽  
Yi Yu Lu ◽  
Dan Li ◽  
Zu Yong Zhou
Keyword(s):  
Rock Mass ◽  
Physical Model ◽  
Model Test ◽  
Physical Models ◽  
Physical Model Test ◽  
Stress Distributions ◽  
Failure Characteristics ◽  
Layered Rock ◽  
Layered Rock Mass ◽  
Dip Angle

Physical models of layered rock mass with different dip angles are built by physical model test in accordance with the bias failure characteristics of surrounding rocks of layered rock mass in Gonghe Tunnel. Bias failure characteristics of surrounding rocks in thin-layered rock mass and influences of layered rock mass dip angle on stability of tunnel are studied. The research results show that failure characteristics of physical models generally coincide with those of surrounding rocks monitored from the tunnel site. The failure regions of surrounding rock perpendicular to the stratification planes are obviously larger than those parallel to. The stress distributions and failure characteristics in the surrounding rocks are similar to each physical model of different dip angles. The stress distributions and failure regions are all elliptic in shape, in which the major axis is in the direction perpendicular to the stratification planes while the minor axis is parallel to them. As a result, obvious bias failure of surrounding rocks has gradually formed. The physical model tests provide reliable basis for theoretical analysis on the failure mechanism of deep-buried layered rock mass.

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