Bowl-Type Diffusers for Low Specific-Speed Pumps: An Industrial Application

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Paolo Boncinelli ◽  
Roberto Biagi ◽  
Antonio Focacci ◽  
Umberto Corradini ◽  
Andrea Arnone ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Aerodynamic Design ◽  
Three Dimensional Flow ◽  
Aerodynamic Efficiency ◽  
Recovery Capacity ◽  
Computational Fluid Dynamics Analysis ◽  
Critical Problems ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Numerical Solver

In this paper, the aerodynamic design of a bowl-type diffuser for a low specific-speed pump is presented and described in detail. The main goal was to achieve an optimal configuration in terms of diffuser recovery capacity and stage aerodynamic efficiency, while satisfying severe constraints concerning stage size and multistage feasibility. Both geometrical parametrization tools and a fully viscous three-dimensional numerical solver were exploited in the design process. The geometrical parametrization allowed one to control and modify the geometry of the component by changing a limited number of parameters. Computational fluid dynamics analysis was exploited to assess the effectiveness of the geometrical modifications on the performance and to identify critical problems. A number of aerodynamic 1D coefficients with simple physical meanings were also introduced and used as a support to the design to synthesize the main feature of the strongly three-dimensional flow evolving in the component. As a result, a new stage configuration was developed according to the imposed constraints, whose performance is at the same level as standard pumps of the same class.

Bowl-Type Diffusers for Low Specific-Speed Pumps: An Industrial Application

2006 ◽  
Author(s):  
Paolo Boncinelli ◽  
Roberto Biagi ◽  
Antonio Focacci ◽  
Umberto Corradini ◽  
Andrea Arnone ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Cfd Analysis ◽  
Aerodynamic Design ◽  
Three Dimensional Flow ◽  
Aerodynamic Efficiency ◽  
Recovery Capacity ◽  
Critical Problems ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Numerical Solver

In this paper, the aerodynamic design of a bowl–type diffuser for a low specific–speed pump is presented and described in detail. The main goal was to achieve an optimal configuration in terms of diffuser recovery capacity and stage aerodynamic efficiency, while satisfying severe constraints concerning stage size and multistage feasibility. Both geometrical parametrization tools and a fully–viscous three–dimensional numerical solver were exploited in the design process. The geometrical parameterization allowed one to control and modify the geometry of the component by changing a limited number of parameters. CFD analysis was exploited to assess the effectiveness of the geometrical modifications on the performance, and to identify critical problems. A number of aerodynamic ID coefficients with simple physical meanings were also introduced and used as a support to the design to synthesize the main feature of the strongly three–dimensional flow evolving in the component. As a result, a new stage configuration was developed according to the imposed constraints, whose performance is at the same level as standard pumps of the same class.

Performance Evaluation of Centrifugal Compressor Impellers Using Three-Dimensional Viscous Flow Calculations

1984 ◽  
Vol 106 (2) ◽  
pp. 475-481 ◽  
Author(s):  
J. Moore ◽  
J. G. Moore ◽  
P. H. Timmis
Keyword(s):  
Viscous Flow ◽  
Centrifugal Compressor ◽  
Strong Influence ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Tip Leakage Flow ◽  
Compression Process ◽  
Tip Leakage ◽  
Low Specific Speed ◽  
Specific Speed

Calculations of three-dimensional viscous flow in the impeller of a centrifugal compressor are used as the basis of a study of the thermodynamics of the compression process. Flow in a high hub-tip ratio low specific speed impeller of approximately 3.4:1 pressure ratio is considered. Results are presented showing the work and loss production processes in the impeller. A strong influence of tip-leakage flow on the performance of this unshrouded wheel is found.

The effect of wear ring clearance on flow field in the impeller sidewall gap and efficiency of a low specific speed centrifugal pump

2017 ◽  
Vol 232 (17) ◽  
pp. 3062-3073 ◽  
Author(s):  
M DaqiqShirazi ◽  
R Torabi ◽  
A Riasi ◽  
SA Nourbakhsh
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Volumetric Efficiency ◽  
Centrifugal Pumps ◽  
Disk Friction ◽  
Low Specific Speed ◽  
Overall Efficiency ◽  
Specific Speed

In this paper, the flow in the impeller sidewall gap of a low specific speed centrifugal pump is analyzed to study the effect of wear ring clearance and the resultant through-flow on flow field in this cavity and investigate the overall efficiency of the pump. Centrifugal pumps are commonly subject to a reduction in the flow rate and volumetric efficiency due to abrasive liquids or working conditions, since the wear rings are progressively worn, the internal leakage flow is increased. In the new operating point, the overall efficiency of the pump cannot be predicted simply by using the pump characteristic curves. The flow field is simulated with the use of computational fluid dynamics and the three-dimensional full Navier–Stokes equations are solved using CFX software. In order to verify the numerical simulations, static pressure field in volute casing and pump performance curves are compared with the experimental measurements. The results show that, for the pump with minimum wear ring clearance, the disk friction efficiency is the strongest factor that impairs the overall efficiency. Therefore, when the ring clearance is enlarged more than three times, although volumetric efficiency decreases effectively but the reduction in overall efficiency is remarkably smaller due to improvement in the disk friction losses.

Performance Investigations of Large Capacity Centrifugal Compressors

1978 ◽  
Author(s):  
H. Mishina ◽  
I. Gyobu
Keyword(s):  
Pressure Ratio ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Design Procedure ◽  
Test Results ◽  
Three Dimensional Flow ◽  
Loss Analysis ◽  
Area Distribution ◽  
Specific Speed ◽  
Sectional Shape

An experimental investigation concerning the optimum relative velocity distribution within impellers, the optimum diffusion ratio of vaned diffusers and the optimum circumferential area distribution, sectional shape of scrolls was carried out using high specific speed shrouded impellers with backward leaning blades. A performance design procedure based on loss analysis and quasi-three-dimensional flow analysis was also developed and modified by introducing experimental results. The design procedure was applied to a 7900-kw four-stage air compressor to demonstrate the usefulness. Field test results of the complete machine showed that the maximum isothermal efficiency was 75 percent with the pressure ratio of 5.96 and the flow rate of 29.3 m3/s.

Performance of a Mixed Flow Pump with Varying Tip Clearance: Part 1

1996 ◽  
Vol 210 (4) ◽  
pp. 305-318 ◽  
Author(s):  
T K Saha ◽  
S Soundranayagam
Keyword(s):  
Angular Momentum ◽  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Reversal ◽  
Tip Clearance ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Specific Speed ◽  
Flow Pump

Measurements of the three-dimensional flow field entering and leaving a mixed flow pump of non-dimensional specific speed k = 1.89 [ Ns = 100 r/min (metric)] are discussed as a function of flowrate. Flow reversal at inlet at reduced flows is seen to result in abnormally high total pressures in the casing region, but causes no noticeable discontinuities on the head-flow characteristics. Inlet prerotation is associated with the transport of angular momentum by the reversal eddy and begins with the initiation of flow reversal.

scholarly journals Three-Dimensional Inverse Design of Low Specific Speed Turbine for Energy Recovery in Cooling Tower System

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3348
Author(s):  
Wei Yang ◽  
Xiaoyu Lei ◽  
Benqing Liu
Keyword(s):  
Response Surface ◽  
Three Dimensional ◽  
Inverse Design ◽  
Design Parameters ◽  
Design Criteria ◽  
Blade Loading ◽  
Turbine Runner ◽  
Lean Angle ◽  
Low Specific Speed ◽  
Specific Speed

A three-dimensional inverse design of a low specific speed turbine is studied, and a set of design criteria for low specific speed turbine runner is proposed, including blade loading distributions and blade lean angles. The characteristics of the loading parameters for low specific speed turbine runner are summarized by analyzing the suction performance of different loading positions, loading slopes and blade lean angles based on the orthogonal experiment design and range analysis. It is found that the blade loading distribution at the band plays a more important role than it does at the crown and it should be fore loaded for both band and crown. The blade lean angle at the blade leading edge should be negative. Then, the blade is optimized through the inverse method by fixing blade lean angle, based on the response surface method. After seeking the optimal value of the response surface function, the optimal result of the design parameters is obtained, which is in conformity with the design criteria and verifies the rationality of the established design criteria for low specific speed turbine.

scholarly journals Assessment of a Neural-Network-Based Optimization Tool: A Low Specific-Speed Impeller Application

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Matteo Checcucci ◽  
Federica Sazzini ◽  
Michele Marconcini ◽  
Andrea Arnone ◽  
Mario Coneri ◽  
...  
Keyword(s):  
Neural Network ◽  
Fluid Dynamic ◽  
Optimization Technique ◽  
Three Dimensional ◽  
Design Procedure ◽  
Design Flow ◽  
Centrifugal Impeller ◽  
Geometrical Constraints ◽  
Low Specific Speed ◽  
Specific Speed

This work provides a detailed description of the fluid dynamic design of a low specific-speed industrial pump centrifugal impeller. The main goal is to guarantee a certain value of the specific-speed number at the design flow rate, while satisfying geometrical constraints and industrial feasibility. The design procedure relies on a modern optimization technique such as an Artificial-Neural-Network-based approach (ANN). The impeller geometry is parameterized in order to allow geometrical variations over a large design space. The computational framework suitable for pump optimization is based on a fully viscous three-dimensional numerical solver, used for the impeller analysis. The performance prediction of the pump has been obtained by coupling the CFD analysis with a 1D correlation tool, which accounts for the losses due to the other components not included in the CFD domain. Due to both manufacturing and geometrical constraints, two different optimized impellers with 3 and 5 blades have been developed, with the performance required in terms of efficiency and suction capability. The predicted performance of both configurations were compared with the measured head and efficiency characteristics.

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