Analyses of the Compressor Performance Impacts of Centrifugal Compressor Scroll Deformation Due to Installation

2010 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Local Deformation ◽  
Discharge Pipe ◽  
Gas Compression ◽  
Study Results ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance ◽  
And Performance

Centrifugal compressors have widely applications in industrial gas compression processes. Limitations of installation and compressor package always request to modify the compressor geometry to fit certain constrains. Very often, the modifications of the scroll were performed to meet the space constrains. To meet the installation and package requirements, we always modify the scroll and discharge pipe of the compressors. In this study, an original designed scroll and a modified scroll were analyzed by using the Computational Fluid Dynamics (CFD). The study is focused on the performance impacts of the scroll local deformation due to installation constrains. The CFD showed favorable agreements with experiments for original scroll. The detailed flow characters and performance impacts were discussed and results showed that current modifications of the scroll did not have significant impacts to the compressor performance. The study results can be used as a basic guidance for a compressor manufactures.

Computational fluid dynamics analysis of the effect of throat diameter on the fluid flow and performance of ejector

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammadreza Salehi ◽  
Nader Pourmahmoud ◽  
Amir Hassanzadeh ◽  
S. Hoseinzadeh ◽  
P.S. Heyns
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Mach Number ◽  
Content Type ◽  
Standard Code ◽  
Computational Fluid Dynamics Analysis ◽  
Fluent Software ◽  
Computational Fluid Dynamics Cfd ◽  
Throat Diameter ◽  
And Performance

Purpose Using the computational fluid dynamics (CFD) technique, this paper aims to investigate the influence of key parameters such as throat diameter; the suction ratio on the flow field behaviors such as Mach number; pressure; and temperature. Design/methodology/approach To investigate the effect of throat diameter, it is simulated for 4, 6, 8 and 10 mm as throat diameters. The governing equations have been solved by standard code of Fluent Software together with a compressible 2 D symmetric and turbulence model with the standard k–ε model. First, the influence of the throat diameter is investigated by keeping the inlet mass flow constant. Findings The results show that a place of shock wave creation is changed by changing the throat diameter. The obtained results illustrate that the maximum amount of Mach number is dependent on the throat diameter. It is obtained from the results that for smaller throats higher Mach numbers can be obtained. Therefore, for mixing purposes smaller throats and for exhausting bigger throats seems to be appropriate. Originality/value The obtained numerical results are compared to the existing experimental ones which show good agreement.

Investigation of the flow in a small-scale turbocharger centrifugal compressor

2016 ◽  
Vol 231 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Hamid R Hazby ◽  
Liping Xu ◽  
Michael V Casey
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Numerical Study ◽  
Optical Measurements ◽  
Small Scale ◽  
Flow Features ◽  
Design Speed ◽  
And Performance ◽  
Compressor Map

This paper presents an experimental and numerical study of the flow in a 1:1 scale, automotive turbocharger centrifugal compressor. Particle image velocimetry measurements have been carried out in the vaneless diffuser at 50% of the design speed. The challenges involved in taking optical measurements in the current small-scale compressor rig are discussed. The overall stage performance and the measured diffuser flow are compared with the results of steady-state computational fluid dynamics calculations. A good agreement between the computational fluid dynamics and the experimental results demonstrates that the numerical methods are capable of predicting the main flow features within the compressor. The synthesis of measured and predicted data is used to explain the sources of the flow and performance variations across the compressor map, and the differences in loss production between small and large compressors are highlighted.

Effects of Impeller Squealer Tip on Centrifugal Compressor Performance

2016 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Lorenzo Toni ◽  
Dante Tommaso Rubino
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Flow ◽  
Tip Clearance ◽  
Flow Coefficient ◽  
Performance Improvements ◽  
Positive Effects ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance ◽  
Load Conditions

This paper summarizes the main results sorted out from a Design of Experiment (DoE) based on a validated Computational Fluid Dynamics (CFD). Several tip recessed geometries applied to an unshrouded impeller were considered in conjunction with two tip clearance levels. The computations show that recessed tip geometries have positive effects when considering high flow coefficient values while in part-load conditions the gain is reduced. Starting from the results obtained when studying tip cavities, a single rim tip squealer geometry was then analysed: the proposed geometry leads to performance improvements for all the tested conditions considered in this work.

scholarly journals An investigation into contracted loaded tip propellers using computational fluid dynamics (CFD)

2018 ◽  
Author(s):  
N R J Williams
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Test Data ◽  
Experimental Test ◽  
Performance Improvements ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
Cfd Method ◽  
Developed Pressure

This paper investigates the potential performance improvements of adding contracted loaded tips to propellers. A Wageningen B5-75 Series propeller has been simulated and verified against published experimental test data. Contracted tips have then been added to a Wageningen propeller and the modified propeller then simulated. A CFD method and model has been developed. Pressure, velocity and vector plots have all been analysed detailing the mechanism behind the contracted tips. Limitations behind this method have been explored and explained, and recommendations for further studies made. The development of a database of propeller characteristics and performance chart data to allow quick evaluation of designs has also been proposed. 

Integrated Approach to Multiphase Flow Regime Prediction Through Computational Fluid Dynamics CFD

2021 ◽  
Author(s):  
Matt Straw ◽  
Ravindra Aglave ◽  
Rodolfo Piccioli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Multiphase Flow ◽  
Case Studies ◽  
Cfd Simulation ◽  
Process Systems ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
Modelling Methods ◽  
Modelling Approaches

Abstract This paper presents recent advances in multiphase modelling methods in Computational Fluid Dynamics (CFD). It uses case studies to show how integration of advanced multiphase modelling approaches can improve the fidelity and realism of simulation of separation and process systems; helping improve design and performance. CFD has been widely used to aid the design and operational performance of many separation and multiphase production and process systems; often providing significant insight and performance improvement. Traditionally, numerous compromises or simplifications must be made when simulating complex multiphase flows and their transitions within production and separation systems using CFD. For example, the modelling methods applicable to capture gas-liquid or liquid-liquid interface behaviour are not suitable (or practical) to also capture gas columns, liquid films or liquid entrainment phenomena, that may be important to quantifying overall system performance. To accommodate different multiphase phenomena and flow regimes, multiple CFD simulations or approaches have often been required. This can limit the insight or fidelity of a given simulation or, in some cases, mean overall performance cannot be fully quantified (even though useful performance indicators may still be identified). Here, the authors present advances in hybrid multiphase modelling and how integration of multiphase modelling approaches enables multiple multiphase flow regimes and their transition to be captured through CFD simulation. The paper will demonstrate how these advances enables simulation of more complex behaviours with increased fidelity. Examples, case studies and validation cases are presented demonstrating phenomena including bulk liquid interface break-up, liquid film formation and entrainment of droplets plus their break—up and deposition. The examples will be presented in the context of the improvements possible in simulation fidelity and realism, of multiphase systems, and how this can impact the insight and value gained from CFD simulation in this complex field. The work presented shows how new developments and evolution of CFD-based predictions can advance how the industry uses this approach and the value that can be obtained. It highlights how integration of the most advanced modelling approaches and methods is key to the next stage of application of CFD to enable better representation of the full range of fluid mechanics that are critical to many separation and multiphase system designs and performance.

Dynamic Instability Analysis of a Spring-Loaded Pressure Safety Valve Connected to a Pipe by Using Computational Fluid Dynamics Methods

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Fengjie Zheng ◽  
Chaoyong Zong ◽  
Chao Zhang ◽  
Xueguan Song ◽  
Fuzheng Qu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamic Instability ◽  
Design Parameters ◽  
Wave Forces ◽  
Cfd Model ◽  
Pressure System ◽  
System Pressure ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance

Abstract As the ultimate protection of a pressure system, pressure safety valves (PSV) can respond in an unstable manner in the form of flutter and chatter, which will affect service life, reliability, and performance. In order to study the dynamic instability caused by multisource forces including the flow force, the spring compression force, and the pressure wave forces, a high-fidelity computational fluid dynamics (CFD) model of the system is proposed. A complete CFD model, incorporating the PSV, connected pipes, and the pressure vessel, is developed, in which advanced techniques in Fluent using User Defined Function (UDF) and Dynamic Layering method are combined to allow the PSV to be coupled to the system dynamics. Based on this model, the valve's opening and reclosing process is monitored to examine the influence of design parameters on the dynamic instability of the PSV. Specifically, the propagation of pressure waves along the connecting pipes is successfully captured, helping to assess the instability mechanism and provide the ability to optimize the design and setup of pressure relief systems.

Effects of Impeller Squealer Tip on Centrifugal Compressor Performance

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Dante Tommaso Rubino ◽  
Lorenzo Toni
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Flow ◽  
Tip Clearance ◽  
Flow Coefficient ◽  
Performance Improvements ◽  
Positive Effects ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance ◽  
Load Conditions

This paper summarizes the main results sorted out from a design of experiment (DoE) based on a validated computational fluid dynamics (CFD). Several tip recessed geometries applied to an unshrouded impeller were considered in conjunction with two tip clearance levels. The computations show that recessed tip geometries have positive effects when considering high-flow coefficient values, while in part-load conditions the gain is reduced. Starting from the results obtained when studying tip cavities, a single rim tip squealer geometry was then analyzed: the proposed geometry leads to performance improvements for all the tested conditions considered in this work.

The Performance Influences of a Centrifugal Compressor Due to Volute Local Deformation

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Numerical Analysis ◽  
Centrifugal Compressor ◽  
Engine Performance ◽  
Local Deformation ◽  
Hydraulic Diameter ◽  
Cfd Analysis ◽  
Compressor Stage ◽  
Gas Compression ◽  
The Future ◽  
Compressor Performance

Centrifugal compressors have broad applications in gas compression processes, especially in automobile turbocharger. During the turbocharger installation, there are many installation limitations in the compressor stage. Due to the restriction in the size of the engine bay, it always has limitations of installation for turbochargers. The compressor package always requests to modify the compressor geometry to fit specific constraints. The volute is the largest geometry of the turbocharger package in most of the case. Very often modifications of the volute were performed to meet the space constraints. In this study, the authors investigated the compressor performance for an initially designed volute and a modified volute. The study followed by an on engine performance comparisons, compressor performance gas stand tests and computational fluid fynamics (CFD) analysis. The studies provided the performance impacts of the local volute deformation due to installation constraints, i.e., a kink in a volute. The studies showed the local volute kink has small implications on compressor performance when the maximum kink depth is less than 10% of the local volute hydraulic diameter. The numerical analysis is in favorable agreements with experiments. The results of this study can be used as a basic guideline for local deformation performance impacts for the future turbocharger compressor volute modifications.

Experimental Results and Computational Fluid Dynamics Simulations of Labyrinth and Pocket Damper Seals for Wet Gas Compression

2015 ◽  
Vol 138 (5) ◽  
Author(s):  
Giuseppe Vannini ◽  
Matteo Bertoneri ◽  
Kenny Krogh Nielsen ◽  
Piero Iudiciani ◽  
Robert Stronach
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Liquid Phase ◽  
Centrifugal Compressor ◽  
Critical Speed ◽  
Operating Conditions ◽  
Liquid Volume ◽  
Wet Gas ◽  
Gas Compression ◽  
Annular Seals

The most recent development in centrifugal compressor technology is toward wet gas operating conditions. This means the centrifugal compressor has to manage a liquid phase which is varying between 0% and 3% liquid volume fraction (LVF) according to the most widely agreed definition. The centrifugal compressor operation is challenged by the liquid presence with respect to all the main aspects (e.g., thermodynamics, material selection, thrust load) and especially from a rotordynamic viewpoint. The main test results of a centrifugal compressor tested in a special wet gas loop (Bertoneri et al., 2014, “Development of Test Stand for Measuring Aerodynamic, Erosion, and Rotordynamic Performance of a Centrifugal Compressor Under Wet Gas Conditions,” ASME Paper No. GT2014-25349) show that wet gas compression (without an upstream separation) is a viable technology. In wet gas conditions, the rotordynamic behavior could be impacted by the liquid presence both from a critical speed viewpoint and stability-wise. Moreover, the major rotordynamic results from the previously mentioned test campaign (Vannini et al., 2014, “Centrifugal Compressor Rotordynamics in Wet Gas Conditions,” 43rd Turbomachinery Symposium, Houston) show that both vibrations when crossing the rotor first critical speed and stability (tested through a magnetic exciter) are not critically affected by the liquid phase. Additionally, it was found that the liquid may affect the vibration behavior by partially flooding the internal annular seals and causing a sort of forced excitation phenomenon. In order to better understand the wet gas test outcomes, the authors performed an extensive computational fluid dynamics (CFD) analysis simulating all the different types of balance piston annular seals used (namely, a tooth on stator (TOS) labyrinth seal and a pocket damper seal (PDS)). They were simulated in both steady-state and transient conditions and finally compared in terms of liquid management capability. CFD simulation after a proper tuning (especially in terms of LVF level) showed interesting results which are mostly consistent with the experimental outcome. The results also provide a physical explanation of the behavior of both seals, which was observed during testing.

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