Modeling the non-incidence inlet flow rate coefficient in a centrifugal compressor impeller

2018 ◽  
Author(s):  
A. A. Drozdov ◽  
Y. B. Galerkin
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Rate Coefficient ◽  
Inlet Flow ◽  
Flow Rate Coefficient ◽  
Inlet Flow Rate ◽  
Compressor Impeller

scholarly journals Stator elements optimization of centrifugal compressor intermediate type stage by CFD methods

2020 ◽  
Vol 178 ◽  
pp. 01020 ◽  
Author(s):  
Lyubov Marenina ◽  
Yuri Galerkin ◽  
Alexandr Drozdov
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Rate Coefficient ◽  
Optimization Problems ◽  
Flow Path ◽  
Loss Coefficient ◽  
Radius Of Curvature ◽  
Intermediate Type ◽  
Flow Rate Coefficient ◽  
Return Channel

Optimal gas-dynamic design is a complex and time-consuming process. Modern CFD methods help in solving optimization problems and reliably calculating characteristics of stator elements of centrifugal compressor stages. To carry out such calculations, it is necessary to create a parametrized model, which facilitates automation of the process of changing the flow path geometry, rebuilding its dimensions and the computational grid. Using the Direct Optimization program of the ANSYS software package, we have optimized the flow path of the stator elements of a centrifugal compressor intermediate type stage consisting of a vaneless diffuser and a return channel. In this paper, the MOGA (Multi-Objective Genetic Algorithm) optimization method was used. The object of the study was stator elements of one of the model stages designed by the Problem Laboratory of Compressor Engineering, SPbPU. The goal was to achieve the minimum value of the loss coefficient of stator elements when changing 5 geometric parameters: the number of vanes, the inlet vane angle, the height of the vane at the inlet to the return channel vane cascade, the radius of curvature of the leading edge and the thickness of the vane profile. For the best variants based on the results of optimization, the characteristics of the loss coefficient depending on the flow rate coefficient were calculated, their characteristics were compared with the initial variant of the stator elements. The best variant in the design mode has a loss coefficient 4.4% lower than the reference model. With a flow rate coefficient of 1.63 times greater than the calculated one, the optimized variant’s loss coefficient is 33% less.

scholarly journals Issues of gas dynamic characteristics modeling: a study on a centrifugal compressor model stage

2019 ◽  
Vol 140 ◽  
pp. 06003 ◽  
Author(s):  
Aleksey Borovkov ◽  
Igor Voinov ◽  
Yuri Galerkin ◽  
Aleksandr Nikiforov ◽  
Maksim Nikitin ◽  
...  
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Rate Coefficient ◽  
Design Flow ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Gas Dynamic ◽  
Flow Rate Coefficient ◽  
Sst Turbulence Model ◽  
Problem Laboratory

The paper presents the results of CFD-calculations of a centrifugal compressor stage with a high-pressure 3D impeller and a vaneless diffuser. The stage was designed by Prof. A. M. Simonov in the Problem Laboratory of Compressor LPI according to the following design parameters: flow rate coefficient 0.080, loading factor 0.74, and the relative Mach number 0.78. Two design grids were used: 2.4 and 4.4 million cells for the sector with one blade. The entire stage was calculated with a sparser grid. Special “Stage” interface conditions are used to interface the gas-dynamic parameters at the boundary regions. The SST turbulence model was used in the calculations. The results of efficiency characteristics and work coefficient comparison showed the following: in design flow rate all three variants of the calculation overstate the loading factor by 14.3%; the calculated characteristics of polytrophic work coefficient in the staging of 360 degrees are closest to the experimental characteristics, but the absolute value is greater than 12% at a flow rate coefficient of 0.085; the maximum calculated efficiency of a stage (the circle of 360 degrees) is almost equal to the measured maximum efficiency.

scholarly journals Verification of a simplified mathematical model of centrifugal compressor stages

2019 ◽  
Vol 124 ◽  
pp. 01007 ◽  
Author(s):  
A. Rekstin ◽  
K. Soldatova ◽  
Y. Galerkin ◽  
E. Popova
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Rate Coefficient ◽  
Similarity Criteria ◽  
Low Flow ◽  
Design Parameters ◽  
Rate Model ◽  
Modelling Method ◽  
Flow Rate Coefficient ◽  
Measured Efficiency

To calculate the efficiency of a centrifugal compressor, it is sufficient to know the design parameters and similarity criteria: flow rate coefficient, loading factor, relative hub ratio, Mach number. The effect of the inlet nozzle and the diffuser type is also taken into account. The original simplified model was successfully used for calculation of compressors’ candidates in computer programs of the Universal Modelling Method. Recently, the model has undergone significant revision and been remade. The modernized model is used in the program for primary design of centrifugal compressors. The authors verified the new model, comparing the calculated efficiency with the measured efficiency of several dozens of model stages 21CV family and low flow rate model stages. In total, calculations were carried out for more than thirty model stages. The range of design parameters of analysed model stages is quite wide: flow rate coefficient 0.00564 – 0.0676; loading factor 0.384 – 0.742; hub ratio 0.258 – 0.466.

scholarly journals Ansys CFX numerical study of stages centrifugal compressor with low-flow rate coefficient

2018 ◽  
Vol 245 ◽  
pp. 09002 ◽  
Author(s):  
Aleksey Yablokov ◽  
Ivan Yanin ◽  
Aleksey Danilishin ◽  
Anatoliy Zuev
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Rate Coefficient ◽  
Numerical Study ◽  
Low Flow ◽  
Computational Domain ◽  
Shaft Seal ◽  
Flow Rate Coefficient ◽  
Numerical Research ◽  
Low Flow Rate

The article presents results of applying the methods of computational fluid dynamics for model low-flow rate stages of centrifugal compressors with flow rate coefficient F = 0.028. The computational domain of a model centrifugal compressor for CFD-simulation consists of the following elements: inlet chamber, impeller, vaneless diffuser, return channel, outlet chamber, shaft seal labyrinth, front and back shroud leakage. Full-scale experimental studies were conducted to model stage 028 in air at an inlet pressure of p* = 1 atm. Numerical research for stage 028 held with flow rate coefficient F=(0.019-0.046) for three variants trailing edge of the impeller. According to the results of numerical research are constructed performances of stages centrifugal compressor and conducted verification of results. Estimated discrepancy between the results of numerical researches on the model with shaft seal labyrinth and without shaft seal labyrinth.

scholarly journals Investigation of the transport characteristics of Pb(II) in sand-bone char columns

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110236
Author(s):  
Gang Li ◽  
Jinli Zhang ◽  
Jia Liu ◽  
Tao Luo ◽  
Yu Xi
Keyword(s):  
Adsorption Capacity ◽  
Flow Rate ◽  
Dose Response ◽  
Construction Materials ◽  
Column Height ◽  
Maximum Adsorption Capacity ◽  
Complexation Reaction ◽  
Bone Char ◽  
Inlet Flow ◽  
Inlet Flow Rate

Pb(II) leakage from batteries, dyes, construction materials, and gasoline threaten human health and environmental safety, and suitable adsorption materials are vitally important for Pb(II) removal. Bone char is an outstanding adsorbent material for water treatment, and the effectiveness in Pb(II) removing need to be verified. In this paper, the transport characteristics of Pb(II) in columns filled with a sand and bone char mixture were studied at the laboratory scale, and the influences of the initial concentration, column height, inlet flow rate, and competing ion Cu(II) on Pb(II) adsorption and transport were analyzed. The Thomas and Dose-Response models were used to predict the test results, and the mechanisms of Pb(II) adsorption on bone char were investigated. The results showed that the adsorption capacity of the bone char increased with increasing column height and decreased with increasing initial Pb(II) concentration, flow rate, and Cu(II) concentration. The maximum adsorption capacity reached 38.466 mg/g and the saturation rate was 95.8% at an initial Pb(II) concentration of 200 mg/L, inlet flow rate of 4 mL/min, and column height of 30 cm. In the competitive binary system, the higher the Cu(II) concentration was, the greater the decreases in the breakthrough and termination times, and the faster the decrease in the Pb(II) adsorption capacity of the bone char. The predicted results of the Dose-Response model agreed well with the experimental results and were significantly better than those of the Thomas model. The main mechanisms of Pb(II) adsorption on bone char include a surface complexation reaction and the decomposition-replacement-precipitation of calcium hydroxyapatite (CaHA). Based on selectivity, sensitivity, and cost analyses, it can be concluded that bone char is a potential adsorbent for Pb(II)-containing wastewater treatment.

Research on the Removal Results of Hydrogen Sulfide of the Treatment of Coal Gasification Wastewater Biogas in the Anaerobic Biotrickling Filter

2012 ◽  
Vol 610-613 ◽  
pp. 2000-2005
Author(s):  
Chun Yan Xu ◽  
Hong Jun Han
Keyword(s):  
Hydrogen Sulfide ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Retention Time ◽  
Operating Parameters ◽  
Inlet Flow ◽  
H2s Removal ◽  
Outlet Concentration ◽  
Volume Load ◽  
Inlet Flow Rate

The uncertainty of operating parameters hinders the practical application of the biological desulfurization. To solve this problem, this study which was conducted in room temperature, pH around seven conditions, investigated the effects of the operating parameters on the hydrogen sulfide (H2S) removal performance in the biotrickling filter, including inlet H2S concentration, inlet flow rate or gas retention time, inlet volume load and circulating liquid spraying flux. The results showed that, the inlet H2S concentration should be controlled within 800mg/m3, 650mg/m3, 400mg/m3, 300mg/m3 respectively while the inlet flow rate was 150L/h, 200L/h, 250L/h, 300L/h, at those conditions, the outlet H2S concentrations were lower than 8mg/m3 and the H2S removal efficiencies were more than 98%. The optimum gas retention time was 12.37s, corresponding to the inlet flow rate of 200L/h, at this time, even if the inlet H2S concentration as high as 700mg/m3, the removal efficiency could be still more than 98%, the outlet concentration of H2S was only 13.1mg/m3. The maximum inlet volume load was 130g/(m3•h), in this condition, the outlet concentration of H2S could be controlled below 12mg/m3, the removal efficiency could above 98.4%.

A new method for prediction of the acoustic performance and design parameter sensitivity analysis of multi-chamber perforated resonators with an irregular cross-section

2021 ◽  
pp. 1-24
Author(s):  
Rong Guo ◽  
Zanzan Sun ◽  
Zhen Huang ◽  
Rui Luo
Keyword(s):  
Theoretical Prediction ◽  
Cross Section ◽  
Flow Rate ◽  
New Method ◽  
Frequency Noise ◽  
Acoustic Characteristics ◽  
Inlet Flow ◽  
Acoustic Performance ◽  
Inlet Flow Rate ◽  
Prediction Approach

Abstract Aiming at reducing the high-amplitude and wide-frequency noise in charged air intake system of the powertrain, this paper proposes a new method for predicting the acoustic characteristics of an irregular cross-section multi-chamber perforated resonator under flow conditions. By this method, the presence of three-dimensional sound waves and the effects of higher-order modes are considered, and the acoustic performance of the resonator can be evaluated through the computation of transmission loss. Moreover, by discretizing the cross-section of perforated resonator and extracting node information, this method can solve the acoustic characteristics of the perforated resonator with any cross-section. Based on the transfer matrix method, the quadrupole parameters of each chamber are obtained. Then the acoustic characteristics of the multi-chamber perforated resonator could be calculated. The theoretical prediction data and the experimental data have been compared and the results show good agreement within the entire frequency range, which verifies the accuracy of the theoretical prediction approach. Based on this prediction approach, the influence of section ratio, structure parameters and inlet flow rate on the acoustic characteristics of the resonator is explored. The results show that when the structural parameters change, the peak resonance frequency of the resonator will have a regular shift. With the increase of the inlet flow rate, the main frequency band of sound attenuation will decrease significantly. The theoretical method developed in this work can be used for the calculation and optimization of multi-chamber resonators in various applications.

Flow Analysis of a Hydrocyclone Designed to High Oil Content Application

2009 ◽  
Author(s):  
G. M. Raposo ◽  
A. O. Nieckele
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Oil Content ◽  
Flow Analysis ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Tangential Component ◽  
Inlet Flow ◽  
Unit Process ◽  
Inlet Flow Rate

Development of small size and weight separation equipment are crucial for the petroleum off-shore exploration. Since centrifugal fields are several times stronger than the gravity field, cyclonic separation has became very important as a unit process for compact gas-liquid, liquid-liquid and solid-liquid separation. The major difference between the various cyclones is their geometry. Cyclone optimization for different uses is, every year, less based on experiments and more based on mathematical models. In the present work, the flow field inside high oil content hydrocyclones is numerically obtained with FLUENT. The performance of two turbulence models, Reynolds Stress Model (RSM) and Large Eddy Simulation (LES), to predict the flow inside a high oil content hydrocyclone, is investigated by comparing the results with experimental data available in the literature. All models overpredicted the tangential component, especially at the reverse cone region. However, the prediction of the tangential turbulent fluctuations with LES was significant better than the RSM prediction. The influences of the inlet flow rate and hydrocyclone length in the flow were also evaluated. RSM model was able to foresee correctly, in agreement with experimental data, the correct tendency of pressure drop reduction with decreasing inlet flow rate and increasing length.

scholarly journals Numerical Study of Bubble Rising and Coalescence Characteristics under Flow Pulsation Based on Particle Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Ronghua Chen ◽  
Minghao Zhang ◽  
Kailun Guo ◽  
Dawei Zhao ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Flow Instability ◽  
Numerical Study ◽  
Phase Flow ◽  
Flow Pulsation ◽  
Two Phase ◽  
Inlet Flow ◽  
Inlet Flow Rate ◽  
Bubble Rising

Two-phase flow instability may occur in nuclear reactor systems, which is often accompanied by periodic fluctuation in fluid flow rate. In this study, bubble rising and coalescence characteristics under inlet flow pulsation condition are analyzed based on the MPS-MAFL method. To begin with, the single bubble rising behavior under flow pulsation condition was simulated. The simulation results show that the bubble shape and rising velocity fluctuate periodically as same as the inlet flow rate. Additionally, the bubble pairs’ coalescence behavior under flow pulsation condition was simulated and compared with static condition results. It is found that the coalescence time of bubble pairs slightly increased under the pulsation condition, and then the bubbles will continue to pulsate with almost the same period as the inlet flow rate after coalescence. In view of these facts, this study could offer theory support and method basis to a better understanding of the two-phase flow configuration under flow pulsation condition.

Application of Sonic Nozzle in Unsteady Flow Rate Generating System for Compressible Fluid

2014 ◽  
Vol 496-500 ◽  
pp. 703-706
Author(s):  
Xiao Xin Wang ◽  
Tao Wang ◽  
Jun Zheng Wang
Keyword(s):  
Unsteady Flow ◽  
Flow Rate ◽  
Compressible Fluid ◽  
Control Method ◽  
Open Loop ◽  
Inlet Flow ◽  
Sonic Nozzle ◽  
Technical Requirements ◽  
Inlet Flow Rate ◽  
Generating System

To meet the requirement of unsteady flow rate generating system for compressible fluid, an inlet flow rate control method with sonic nozzle is proposed. When inlet flow rate is known, feedback of unsteady flow rate can be obtained by an isothermal tank. A proper sonic nozzle is designed according to the technical requirements, and the flow rate is calculated. Open loop experiments are carried out on generating system with and without sonic nozzle. The results indicate that influence of downstream on upstream can be greatly reduced by the designed sonic nozzle, and accurate feedback of unsteady flow rate is ensured.

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