scholarly journals Numerical Prediction and Performance Experiment in an Engine Cooling Water Pump with Different Blade Outlet Widths

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Li ◽  
Xiaofan Zhao ◽  
Weiqiang Li ◽  
Weidong Shi ◽  
Leilei Ji ◽  
...  
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Static Pressure ◽  
Cooling Water ◽  
Internal Flow ◽  
Water Pump ◽  
Centrifugal Pumps ◽  
Suction Surface ◽  
Engine Cooling ◽  
Performance Curves

Changing the blade outlet width is an important method to adjust the performance curves of centrifugal pumps. In this study, three impellers with different blade outlet widths in an engine cooling water pump (ECWP) were numerically simulated based on ANSYS-CFX software. Numerical calculation reliability was validated based on the comparison between simulation results and experimental datum. As the blade outlet width increases, from the performance curves, the investigated ECWP head increases gradually; and the best efficiency point (BEP) offsets to larger flow rate; and the high efficiency region (HER) is becoming larger; and the critical cavitation pressure of the investigated ECWP at BEP increases, which indicates that the cavitation performance at BEP became worse. Compared with the internal flow field, we find vortex appears mainly in the blade passage near the tongue and volute outlet, and the region of the low static pressure is located in the blade inlet suction surface, and impeller inlet and outlet are the regions of high turbulence kinetic energy. Meanwhile, at the same flow rate, with the increase of blade outlet width, the areas of vortex and low static pressure become obvious and bigger.

scholarly journals Numerical Simulation of Cavitation Performance in Engine Cooling Water Pump Based on a Corrected Cavitation Model

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 278 ◽  
Author(s):  
Wei Li ◽  
Enda Li ◽  
Weidong Shi ◽  
Weiqiang Li ◽  
Xiwei Xu
Keyword(s):  
Cooling Water ◽  
Internal Flow ◽  
Absolute Pressure ◽  
Inlet Section ◽  
Water Pump ◽  
Cavitation Model ◽  
Suction Surface ◽  
Pressure Surface ◽  
Engine Cooling ◽  
Cavitation Performance

To analyze the internal flow of the engine cooling water pump (ECWP) under thermodynamic effect, Zwart cavitation model based on the Rayleigh-Plesset equation is corrected, and NACA0015 hydrofoil was selected to verify the corrected model. The cavitation performances of ECWP with different temperatures were numerically simulated based on a corrected cavitation model. Research results show that simulation values of pressure distribution coefficient in hydrofoil surface at 70 °C are in closest agreement with experimental values when the evaporation and condensation coefficients are 10 and 0.002, respectively. With the decrease of absolute pressure in pump inlet, bubbles firstly occurred at the blade inlet side near the suction surface and then gradually extended to the pressure surface, finally clogged the impeller passage. Compared to the inlet section, the cavitation degree is much more serious close to the trailing edge. With the temperature increases, the cavitation in ECWP occurs in advance and rapidly, and the temperature plays an important role in promoting cavitation process in ECWP. Based on the unsteady simulation of ECWP, the influence of cavitation on the performance characteristics is studied. The results provide a theoretical reference for the prediction and optimization of the cavitation performance in ECWP.

scholarly journals Numerical and experimental study of variable speed automobile engine cooling water pump

2020 ◽  
Vol 103 (2) ◽  
pp. 003685042092522 ◽  
Author(s):  
Wei Li ◽  
Leilei Ji ◽  
Lingling Ma ◽  
Yongfei Yang ◽  
Ling Zhou ◽  
...  
Keyword(s):  
Flow Rate ◽  
Cooling Water ◽  
Internal Flow ◽  
Water Pump ◽  
Tip Leakage Flow ◽  
Rate Condition ◽  
Rotating Speed ◽  
Engine Cooling ◽  
Cavitation Performance ◽  
Rotor Stator Interaction

To investigate the performance of engine cooling water pump in automobile with variable rotating speed, experimental tests and numerical simulation are carried out on an engine cooling water pump under the rotating speed of 2650, 2960, 3700, and 4300 r/min. The hydraulic performance under 3700 r/min rotating speed and the cavitation performance under 340 L/min flow rate are tested and analyzed. The predicted results agree well with the experimental results, indicating that the simulation has high accuracy. The results show that the head of engine cooling water pump increases gradually and the best-effective region moves toward high flow rate condition with the increase in rotating speed. The augment of rotating speed would deteriorate the internal flow fields and causes more energy losses, which is due to the increase in tip leakage flow and enhancement of rotor–stator interaction effects. And, the rotor–stator interaction effect is sensitive to the temperature under various rotating speeds. Furthermore, the required net positive suction head increases with the increase in rotational speed and anti-cavitation performance is weakened during cavitation conditions.

Effective Fuel Consumption by Improving Cooling Water Flow Rate in IC Engine

2015 ◽  
Vol 812 ◽  
pp. 112-117
Author(s):  
K.M. Kumar ◽  
P. Venkateswaran ◽  
P. Suresh
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Water Flow Rate ◽  
Research Work ◽  
Cooling Water ◽  
Major Change ◽  
Clear Understanding ◽  
Water Pump ◽  
Ic Engine ◽  
Cooling Water Flow Rate

The coolant (water) pump assumes an important role of cooling system in IC engines. With upgrading of the engine power by turbocharging and turbo inter cooling, the water pump capacity needs to be increased corresponding to the power. This capacity enhancement has to be achieved without calling for a major change in the existing water pump, envelop and related fitment details. This requires a clear understanding of centrifugal pump for its performance parameter. One such engine is upgraded by turbocharging from 195PS to 240PS @2200 rpm. Improving water pump flow by changing the impeller dimensions, impeller casing, increase the suction, delivery pipe diameter had been done. Validation of the water pump in its actual engine installation was taken up as a part of the research work. Flow rate comparison of the new pump with the existing pump was made and the results were analyzed. The new water pump gives better flow rates for the engine speeds up to1800 rpm, beyond which the flow rate is slightly lesser than the existing pump.

Numerical calculation and optimization designs in engine cooling water pump

2017 ◽  
Vol 31 (5) ◽  
pp. 2319-2329 ◽  
Author(s):  
Li Wei ◽  
Chuan Wang ◽  
Weidong Shi ◽  
Xiaofan Zhao ◽  
Yongfei Yang ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Cooling Water ◽  
Water Pump ◽  
Engine Cooling

Investigation of Internal Flow and Characteristic Instability of a Mixed Flow Pump

2009 ◽  
Author(s):  
Masahiro Miyabe ◽  
Akinori Furukawa ◽  
Hideaki Maeda ◽  
Isamu Umeki
Keyword(s):  
Flow Rate ◽  
Internal Flow ◽  
Rotating Stall ◽  
Leakage Flow ◽  
Suction Surface ◽  
Mixed Flow ◽  
Vaned Diffuser ◽  
Flow Angle ◽  
Pressure Surface ◽  
Flow Pump

The relationship between pump characteristic instabilities and internal flow was investigated in a mixed flow pump with specific speed of 700 (min−1 m3/min, m) or 1.72 (non-dimensional) by using a commercial CFD code and a dynamic PIV (DPIV) measurement. This pump has two positive slopes of a head-flow characteristic at the flow rates of about 60%Qopt and 82%Qopt. In the authors’ previous study, it was clarified that the characteristic instability at 82%Qopt is caused by the diffuser rotating stall (DRS) and the backflow near the hub of the vaned diffuser plays an important role on the onset of the diffuser rotating stall. In the present paper, the investigation is focused on the instability at about 60% Qopt. Based on both of experimental and numerical results, it was clarified that the characteristic instability at 60%Qopt is caused by the backflow at the inlet of the impeller tip and the leakage flow from the impeller pressure surface to the suction surface plays an important role on the onset of the backflow. The behaviors of backflow at the impeller inlet were visualized by the DPIV measurements and CFD simulation. Moreover, internal flow was investigated in detail and the occurrence of characteristic instability is assumed as follows: At the partial flow rate, the flow angle at the inlet of the impeller tip decreases and the flow hits the impeller pressure surface. Then, the blade loading at the inlet of impeller tip is increased and the recirculation at the leading edge and the leakage flow rate from pressure surface to suction surface increases. The leakage flow causes to generate vortices at the inlet of the suction surface of the impeller. As the flow rate is further decreased, the vortices develop to backflow with swirl. The leakage flow has peripheral component of absolute velocity and the swirling energy is continuously supplied by the backflow. Therefore, even the passage flow at the inlet of the impeller has been getting pre-swirling. The theoretical head, the Euler head is decreased due to the pre-swirling. Moreover, based on the CFD results, the pre-swirling and unsteady vortices near the suction surface of the impeller causes pump characteristic instability. When the flow rate is decreased further more, total head rises because the flow pattern in the impeller changes to centrifugal type due to the backflow from the vaned diffuser at the hub region.

scholarly journals Unsteady Characteristics of Forward Multi-Wing Centrifugal Fan at Low Flow Rate

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 691 ◽  
Author(s):  
Lun ◽  
Ye ◽  
Lin ◽  
Ying ◽  
Wei
Keyword(s):  
Unsteady Flow ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Boundary Layer Separation ◽  
Low Flow ◽  
Centrifugal Fan ◽  
Suction Surface ◽  
Cfd Method ◽  
Low Flow Rate

The unsteady flow characteristics of a forward multi-wing centrifugal fan under a low flow rate are studied using the computational fluid dynamics (CFD) method. This paper emphasizes the eddy current distribution in terms of the Q criterion method, as well as pressure fluctuation, frequency spectrum, and kinetic energy spectrum analysis of internal monitoring points in a forward multi-wing centrifugal fan. The numerical results show that abnormal eddies mainly appear at the volute outlet and near the volute tongue, boundary layer separation occurs near the suction surface of the blade, and shedding eddies appear at the trailing edge of the blade with the time evolution. The unsteady flow characteristics of a forward multi-wing centrifugal fan at a small flow rate provide significant physical insight into understanding the internal flow law.

Investigation of Flow Structure in a Narrow Clearance of a Low Specific Speed Centrifugal Impeller

2021 ◽  
Author(s):  
Yumeno Inaba ◽  
Kento Sakai ◽  
Kazuyoshi Miyagawa ◽  
Masamichi Iino ◽  
Takeshi Sano
Keyword(s):  
Pressure Gradient ◽  
Flow Structure ◽  
Flow Rate ◽  
Static Pressure ◽  
Internal Flow ◽  
Friction Loss ◽  
Circumferential Velocity ◽  
Disk Friction ◽  
Low Specific Speed ◽  
Specific Speed

Abstract The disk friction loss is remarkably large in low specific speed centrifugal pumps, and an effective reduction method has not been established. Therefore, to develop such a method, the loss mechanism was investigated. To grasp the internal flow structure in the narrow clearance, both experimental and computational approaches were used. An experimental apparatus that imitates clearance between a rotating impeller disk and a stationary casing disk was used, and the static pressure distribution in the radial direction was measured. The internal flow where the disk friction loss occurs was investigated. In the case of outward flow, the static pressure decreased because the influence of the centrifugal force lessened toward the outer diameter side of the disk, as the flow rate surged. For this reason, the pressure gradient became steep. According to the CFD analysis, there was a vortex in the cross-section of the clearance. This vortex encouraged flow recirculation and promoted the increased of the circumferential velocity in the potential core. When the flow rate grew, the vortex diminished. The circumferential velocity gradient and the shear stress intensified. As a result, the disk friction escalated. In the case of inward flow, the pressure gradient became steep as the flow rate increase. There was a vortex in the clearance, the size of which lessened when the flow rate surged. The disk friction had a minimum value at the flow rate was 6e-4 m3/s. This research clarified that the vortex in the clearance has a remarkable effect on reducing the disk friction.

scholarly journals Design of High Efficiency Blowers for Future Aerosol Applications

2009 ◽  
Author(s):  
Raman Chadha ◽  
Gerald L. Morrison ◽  
Andrew R. McFarland
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Static Pressure ◽  
Pressure Rise ◽  
Electrical Energy ◽  
Design Flow ◽  
Preliminary Design ◽  
Aerosol Sampling ◽  
Wall Functions ◽  
Low Efficiency

High efficiency air blowers to meet future portable aerosol sampling applications were designed, fabricated, and their performance evaluated. A preliminary blower design based on specific speed was selected, modeled in CFD, and the flow field simulated. This preliminary blower size was scaled in planar and axial directions, at different rpm values, to set the Best Efficiency Point (BEP) at a flow rate of 100 L/min (1.67×10−3 m3/s @ room conditions) and a pressure rise of 1000 Pa (4″ WC). Characteristic curves for static pressure rise versus air flow rate through the impeller were generated. Experimentally measured motor/blower combination efficiency (ηEXP) for the preliminary design was around 10%. The low value was attributed to the low efficiency of the D.C. motor used (Chadha, 2005). CFD simulations using the κ–ε turbulent model and standard wall function (non-equilibrium wall functions) approach overpredicted the head values. Enhanced wall treatment under-predicted the head rise but provided better agreement with experimental results. The static pressure rise across the final blower is 1021 Pa at the design flow rate of 100 L/min. Efficiency value based on measured static pressure rise value and the electrical energy input to the motor (ηEXP) is 26.5%, a 160% improvement over the preliminary design.

Effect of Baffles in Between Stages on Performance and Flow Characteristics of a Two-Stage Split Case Centrifugal Pump

2017 ◽  
Author(s):  
Yiyun Wang ◽  
Ji Pei ◽  
Shouqi Yuan ◽  
Wenjie Wang
Keyword(s):  
Centrifugal Pump ◽  
High Efficiency ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Production Method ◽  
Navier Stokes ◽  
Centrifugal Pumps ◽  
Two Stage

Two-stage split case centrifugal pumps play an important role in large flow rate and high lift water transfer situations. To investigate the influence of baffles in between stages on the performance and internal flow characteristics, the unsteady simulations for the prototype pump were carried out by solving the three-dimensional Reynolds-averaged Navier-Stokes equations with a shear stress transport (SST) turbulence model. The structured grids were generated for the whole flow passage. The calculated performance results were verified by the experimental measurements. The entropy production method based on numerical simulation was applied to analyze the distribution and mechanism of flow losses. The results show that the turbulence dissipation is the dominant flow loss, and the viscous dissipation can be neglected. The baffles can reduce the turbulence dissipation power obviously and can improve the hydraulic efficiency by maximum 5%, especially under QBEP and over-load conditions. The baffles have the greatest effect on the hydraulic losses in the double suction impeller., because they change the flow characteristics in the channels between the first stage impeller and the double suction impeller, affecting the inflow condition dramatically for the impeller. The study can give a reference to optimize the design of the two-stage split case centrifugal pump for high efficiency.

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