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.

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.

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 (CFD) Analysis of a Single-Stage Downhole Turbine

2013 ◽  
Author(s):  
Rajani Satti ◽  
Narasimha Rao Pillalamarri ◽  
Eckard Scholz
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Operating Regime ◽  
Single Stage ◽  
Tip Clearance ◽  
Performance Characteristics ◽  
Design Parameters ◽  
Complex Flow ◽  
Computational Fluid Dynamics Cfd

In this study, the application of computational fluid dynamics (CFD) is explored to predict the performance characteristics in a typical single-stage downhole turbine. The single-stage turbine model utilized for this study consists of a stator and a rotor. A finite-volume based CFD approach was implemented to simulate the complex flow field around the turbine. The analysis is based on transient, three-dimensional, isothermal turbulent flow in an incompressible fluid system. The inlet flow rates and angular velocity of the rotor were varied to encompass the operating regime. Comparison with experimental data revealed excellent agreement, proving reliability of the model in predicting the performance characteristics. Motivated by the successful model validation, a parametric study (considering blade tip clearance and blade count) was also conducted to understand the effects of the design parameters on the performance of the turbine. Detailed flow visualizations and efficiency calculations were also done to provide further insight into the overall performance of the turbine. As part of the present study, significant efforts were also spent in the following areas: standardization of CFD methodology and assessment of commercial software to develop an integrated CFD-driven design process.

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. 

A Technological Effect Modeling on Complex Turbomachinery Applications With an Overset Grid Numerical Method

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Lionel Castillon ◽  
Gilles Billonnet ◽  
Jacques Riou ◽  
Stéphanie Péron ◽  
Christophe Benoit
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Simulations ◽  
Tip Clearance ◽  
Overset Grid ◽  
Grid Approach ◽  
Computational Fluid Dynamics Cfd ◽  
Geometrical Effects ◽  
The Impact ◽  
Casing Treatments

This paper presents an overview of numerical simulations performed at ONERA on turbomachinery configurations which include technological effects, such as tip clearance, hub disk leakage, circumferential and noncircumferential casing treatments (CTs), blade fillets, and cooling holes. An overset grid approach (Chimera technique) is used to simulate these geometrical effects with ONERA's structured computational fluid dynamics (CFD) solver elsA. Calculations performed on the different configurations enable to quantify the impact of these technological effects on the flow solution.

On the Use of Computational Fluid Dynamics (CFD) to Assess the Impact of Low-Load Operations on Heat Recovery Steam Generator (HRSG) Tube Module Integrity

2019 ◽  
Author(s):  
Andreas Fabricius ◽  
David S. Moelling ◽  
Jan Rusaas
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Recovery ◽  
Power Plants ◽  
Large Temperature ◽  
Plant Design ◽  
Low Load ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Load Conditions

Abstract As the electricity market has evolved with the addition of renewables to the generation mix, Heat Recovery Steam Generators (HRSGs) that were originally designed for base load conditions are now frequently forced to operate in a cycling and/or low-load regime. This can lead to front end tube-to header fatigue, creep or creep-fatigue failures, often induced by Gas Turbine (GT) flow imbalances causing locally-elevated tube temperatures and/or bending stresses on joints due to large temperature differences between tube rows. This paper focuses on the use of Computational Fluid Dynamics (CFD) as a tool to analyze the risks of shifting operation mode. Exhaust gas flow profiles were analyzed for various low load conditions in two power plants with differing vertical designs. One of the plants had already moved into cycling mode and suffered tube failures that were directly related to low-load (and start-up) exhaust flow patterns, the other plant is projected to operate in a frequent cycling mode in the near future. The contribution of CFD to identifying the conditions that lead to failure for the first plant is presented, along with projections on the potential impact of lowload operation on the second plant design in terms of risk of hotend tube failures. Mechanisms to reduce the failure risk, such as addition of flow-conditioning devices, are also investigated.

A method for the numerical assessment of sediment interceptors

2003 ◽  
Vol 47 (4) ◽  
pp. 167-174 ◽  
Author(s):  
M.G. Faram ◽  
R. Harwood
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Performance Characteristic ◽  
High Flow ◽  
Drainage Systems ◽  
Flow Restriction ◽  
Sewer Systems ◽  
Numerical Assessment ◽  
Computational Fluid Dynamics Cfd

The problems associated with the presence of sediments in sewers and stormwater drainage systems represent a major engineering challenge. Their accumulation can result in operational difficulties, including flow restriction and premature overflows. Sediments themselves are known to contribute significantly to the polluting load of storm overflows. The use of sediment interceptors within sewer systems or downstream of stormwater intakes represents one way of alleviating these problems. A study of stormwater sediment interceptors using Computational Fluid Dynamics (CFD) has identified that the ability of a chamber to retain, as well as remove, sediments is an important performance characteristic. A methodology for the assessment of such characteristics using CFD is presented in the context of a study of different chamber types. This concludes that primitive chambers, for example, gully pots, are likely to be far more prone to flushing out during high flow inputs than advanced systems such as vortex separators.

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