Effects Due to the Temperature Measurement Section on the Performance Estimation of a Centrifugal Compressor Stage

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Alessandro Bianchini ◽  
Giovanni Ferrara ◽  
Lorenzo Ferrari ◽  
Valeria Ballarini ◽  
Lorenzo Bianchi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Exchange ◽  
Temperature Measurement ◽  
Centrifugal Compressor ◽  
Numerical Models ◽  
Performance Estimation ◽  
Centrifugal Impeller ◽  
Outlet Section ◽  
Impeller Outlet ◽  
Total Temperature

A wide-ranging analysis was performed by GE Oil & Gas and the University of Florence to investigate the effects on the estimation of centrifugal compressor performance induced by a different choice of the total temperature measurement section. With this goal in mind, the study focused on the analysis of a commonly found discrepancy between the measurements at the impeller outlet section and at the stage exit section. Based on the experimental data collected on a centrifugal impeller, three main physical phenomena were analyzed and discussed in further detail. First, the effect of the heat exchange was examined, and its influence on the total temperature variation throughout the machine was extrapolated. Next, the influence of the heat-exchange phenomena affecting the temperature sensors was evaluated by means of numerical models and physical assumptions. Finally, the effects on the temperature measurement of the flow structure at the impeller outlet were investigated. In particular, a corrective model to account for the thermal inertia of the thermocouples normally applied in this section was applied to the experimental data. The corrected temperatures at the investigated measurement sections were then compared, and their influence on the correct stage performance estimation is discussed in this study.

Effects due to the Temperature Measurement Section on the Performance Estimation of a Centrifugal Compressor Stage

2011 ◽  
Author(s):  
Alessandro Bianchini ◽  
Giovanni Ferrara ◽  
Lorenzo Ferrari ◽  
Valeria Ballarini ◽  
Lorenzo Bianchi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Exchange ◽  
Temperature Measurement ◽  
Centrifugal Compressor ◽  
Numerical Models ◽  
Performance Estimation ◽  
Centrifugal Impeller ◽  
Outlet Section ◽  
Impeller Outlet ◽  
Total Temperature

A wide-ranging analysis was performed by GE Oil & Gas and the University of Florence to investigate the effects on the estimation of centrifugal compressor performance induced by a different choice of the total temperature measurement section. With this goal in mind, the study focused on the analysis of a commonly found discrepancy between the measurements at the impeller outlet section and at the stage exit section. Based on the experimental data collected on a centrifugal impeller, three main physical phenomena were analyzed and discussed in further detail. First the effect of the heat exchange was examined and its influence on the total temperature variation throughout the machine was extrapolated. Next, the influence of the heat-exchange phenomena affecting the temperature sensors was evaluated by means of numerical models and physical assumptions. Finally, the effects on the temperature measurement of the flow structure at the impeller outlet were investigated. In particular, a corrective model to account for the thermal inertia of the thermocouples normally applied in this section was applied to the experimental data. The corrected temperatures at the investigated measurement sections were then compared and their influence on the correct stage performance estimation is discussed in this study.

scholarly journals Experimental Validation of the Aerodynamic Performance of an Innovative Counter-Rotating Centrifugal Compressor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2582
Author(s):  
Cheikh Brahim ABED ◽  
Sofiane KHELLADI ◽  
Michael DELIGANT ◽  
Abdellatif EL EL MARJANI ◽  
Moisés SOLIS ◽  
...  
Keyword(s):  
Experimental Data ◽  
Centrifugal Compressor ◽  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Design Method ◽  
Pressure Rise ◽  
Design Tool ◽  
Centrifugal Impeller ◽  
Speed Ratio ◽  
And Control

Turbomachinery with double counter-rotating impellers offers more degrees of freedom in the choice of design and control parameters compared to conventional machines. For these innovative machines, the literature review shows that more publications concerning axial type turbomachines are available than centrifugal ones. This work deals with a design and experimental performance analysis, applied to two counter-rotating impellers of a centrifugal compressor “CRCC”. CRCC was designed with a specifically developed tool based on mean-line approach coupled with optimization algorithms and a stream-curvature through-flow method to satisfy the design criteria. This paper presents an experimental validation of the CRCC design tool and its performances against the baseline “SR”, composed of one centrifugal impeller and a volute for which experimental data are available. CRCC numeric simulations are also validated by experimental data. For a fair comparison between CRCC and SR, the same volute is used for both configurations. The CRCC studied here includes a first conventional impeller with an axial inlet and a radial outlet, while the second impeller is parametrically designed and can be considered a rotating bladed diffuser with a radial inlet and outlet. The obtained results show that CRCC can deliver a pressure rise increase of two compared to SR, along with an increase of isentropic efficiency and also validate the design method of this novel layout. The experimental results also show that the speed ratio of CRCC has a positive effect on the surge and shock margin.

Accuracy of Centrifugal Compressor Stages Performance Prediction by Means of High Fidelity CFD and Validation Using Advanced Aerodynamic Probe

2013 ◽  
Author(s):  
V. V. N. K. Satish K. ◽  
Emanuele Guidotti ◽  
Dante Tommaso Rubino ◽  
Libero Tapinassi ◽  
Sridhar Prasad
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Numerical Models ◽  
Cavity Flow ◽  
Pressure Probe ◽  
High Fidelity ◽  
Leakage Flows

During the design of modern high efficiency, wide operating range centrifugal compressor stages, Computational Fluid Dynamics (CFD) plays an increasing role in the assessment of the performance prediction. Nevertheless experimental data are valuable and necessary to assess the performance of the stages and to better understand the flow features in detail. A big effort is currently being made to increase the fidelity of the numerical models and the probe measurement accuracy during both the design and validation phases of centrifugal compressor stages. This study presents the flow analysis of centrifugal compressor stages using high fidelity computational fluid dynamics with a particular attention to the cavity flow modeling and comparison with experimental data, using an advanced fast response aerodynamic pressure probe. Different flow coefficient centrifugal compressor stages were used for the validation of the numerical models with a particular attention to the effects of cavity flow on the flow phenomena. The computational domain faithfully reproduced the geometry of the stages including secondary flow cavities. The availability of a new in-house automated tool for cavity meshing allowed to accurately resolve leakage flows with a reasonable increase in computational and user time. Time averaged data from CFD analysis were compared with advanced experimental ones coming from the unsteady pressure probe, for both overall performance and detailed two-dimensional maps of the main flow quantities at design and off design conditions. It was found that the increase in computational accuracy with the complete geometry modeling including leakage flows was substantial and the results of the computational model were in good agreement with the experimental data. Moreover the combination of both advanced computational and experimental techniques enabled deeper insights in the flow field features. The comparison showed that only with advanced high fidelity CFD including leakage flows modeling did the numerical predictions meet the requirements for efficiency, head and operating margin, otherwise not achievable with simplified models (CFD without cavities).

Identifying Physico-Chemical Laws from the Robotically Collected Data

2019 ◽  
Author(s):  
Liwei Cao ◽  
Danilo Russo ◽  
Vassilios S. Vassiliadis ◽  
Alexei Lapkin
Keyword(s):  
Experimental Data ◽  
Numerical Models ◽  
Predictor Variable ◽  
Physical Models ◽  
Training Data ◽  
Mixed Integer ◽  
Physico Chemical ◽  
Data Points ◽  
Future Work ◽  
The Relationship

<p>A mixed-integer nonlinear programming (MINLP) formulation for symbolic regression was proposed to identify physical models from noisy experimental data. The formulation was tested using numerical models and was found to be more efficient than the previous literature example with respect to the number of predictor variables and training data points. The globally optimal search was extended to identify physical models and to cope with noise in the experimental data predictor variable. The methodology was coupled with the collection of experimental data in an automated fashion, and was proven to be successful in identifying the correct physical models describing the relationship between the shear stress and shear rate for both Newtonian and non-Newtonian fluids, and simple kinetic laws of reactions. Future work will focus on addressing the limitations of the formulation presented in this work, by extending it to be able to address larger complex physical models.</p><p><br></p>

scholarly journals The Problem of Accounting for Heat Exchange between the Flow and the Flow Part Surfaces When Modeling a Viscous Flow in Low-Flow Stages of a Centrifugal Compressor

2020 ◽  
Vol 10 (24) ◽  
pp. 9138
Author(s):  
Sergey Kartashov ◽  
Yuri Kozhukhov ◽  
Vycheslav Ivanov ◽  
Aleksei Danilishin ◽  
Aleksey Yablokov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Centrifugal Compressor ◽  
Calculation Model ◽  
Flow Coefficient ◽  
Low Flow ◽  
Relative Width ◽  
Adiabatic Wall ◽  
Flow Part ◽  
Computational Fluid Dynamics Cfd

In this paper, we review the problem of accounting for heat exchange between the flow and the flow part surfaces when creating a calculation model for modeling the workflow process of low-flow stages of a centrifugal compressor using computational fluid dynamics (CFD). The objective selected for this study was a low-flow intermediate type stage with the conditional flow coefficient Փ = 0.008 and the relative width at the impeller exit b2/D2 = 0.0133. We show that, in the case of modeling with widespread adiabatic wall simplification, the calculated temperature in the gaps between the impeller and the stator elements is significantly overestimated. Modeling of the working process in the flow part was carried out with a coupled heat exchanger, as well as with simplified accounting for heat transfer by setting the temperatures of the walls. The gas-dynamic characteristics of the stage were compared with the experimental data, the heat transfer influence on the disks friction coefficient was estimated, and the temperature distributions in the gaps between disks and in the flow part of the stage were analyzed. It is shown that the main principle when modeling the flow in low-flow stage is to ensure correct temperature distribution in the gaps.

Design of Impeller of Centrifugal Compressor for Water-Air Engine

2014 ◽  
Vol 496-500 ◽  
pp. 642-645
Author(s):  
Yun Wang ◽  
Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Power System ◽  
Centrifugal Compressor ◽  
Centrifugal Impeller ◽  
3D Design ◽  
Pump Impeller ◽  
Aero Engine ◽  
Simulation Results

In view of power system in water-air UAV requirements, combine with the centrifugal impeller for aero-engine and the pump impeller. The design of a impeller of centrifugal compressor can work on the air and in the water for the new concept of air-water engine. With 3D design and a 3D CFD solver on it and analysis the results of numerical simulation. Results show that the designed impeller successfully reached the goal on the air and in the water. The experiences accumulated in this procedure are useful for similar impeller aerodynamic designs.

Effect of Vaned Diffuser on a Modified Turbocharger Centrifugal Compressor Performance

2014 ◽  
Vol 663 ◽  
pp. 347-353
Author(s):  
Layth H. Jawad ◽  
Shahrir Abdullah ◽  
Zulkifli R. ◽  
Wan Mohd Faizal Wan Mahmood
Keyword(s):  
Centrifugal Compressor ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Width Ratio ◽  
Outlet Section ◽  
Suction Surface ◽  
Vaned Diffuser ◽  
Minimum Width

A numerical study that was made in a three-dimensional flow, carried out in a modified centrifugal compressor, having vaned diffuser stage, used as an automotive turbo charger. In order to study the influence of vaned diffuser meridional outlet section with a different width ratio of the modified centrifugal compressor. Moreover, the performance of the centrifugal compressor was dependent on the proper matching between the compressor impeller along the vaned diffuser. The aerodynamic characteristics were compared under different meridional width ratio. In addition, the velocity vectors in diffuser flow passages, and the secondary flow in cross-section near the outlet of diffuser were analysed in detail under different meridional width ratio. Another aim of this research was to study and simulate the effect of vaned diffuser on the performance of a centrifugal compressor. The simulation was undertaken using commercial software so-called ANSYS CFX, to predict numerically the performance charachteristics. The results were generated from CFD and were analysed for better understanding of the fluid flow through centrifugal compressor stage and as a result of the minimum width ratio the flow in diffuser passage tends to be uniformity. Moreover, the backflow and vortex near the pressure surface disappear, and the vortex and detachment near the suction surface decrease. Conclusively, it was observed that the efficiency was increased and both the total pressure ratio and static pressure for minimum width ratio are increased.

Leakage Flow Investigations on a Through-Wall Crack Related to Thermal Fatigue of Nuclear Power Plant Piping

2017 ◽  
Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien
Keyword(s):  
Experimental Data ◽  
Nuclear Power ◽  
Numerical Models ◽  
Measurement Techniques ◽  
Experimental Investigations ◽  
Leakage Flow ◽  
Test Rig ◽  
Reduced Pressure ◽  
Flow Rates ◽  
Set Up

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.

scholarly journals Temperature Measurement at Curved Surfaces Using 3D Printed Planar Resistance Temperature Detectors

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1100
Author(s):  
Adam Steckiewicz ◽  
Kornelia Konopka ◽  
Agnieszka Choroszucho ◽  
Jacek Maciej Stankiewicz
Keyword(s):  
Temperature Measurement ◽  
Fused Deposition Modeling ◽  
Numerical Models ◽  
Elastic Base ◽  
Measuring Device ◽  
Fused Deposition ◽  
Influence Of Temperature On ◽  
Printed Sensors ◽  
Analytical Formulae ◽  
3D Printed

In this article, novel 3D printed sensors for temperature measurement are presented. A planar structure of the resistive element is made, utilizing paths of a conductive filament embedded in an elastic base. Both electrically conductive and flexible filaments are used simultaneously during the 3D printing procedure, to form a ready–to–use measuring device. Due to the achieved flexibility, the detectors may be used on curved and irregular surfaces, with no concern for their possible damage. The geometry and properties of the proposed resistance detectors are discussed, along with a printing procedure. Numerical models of considered sensors are characterized, and the calculated current distributions as well as equivalent resistances of the different structures are compared. Then, a nonlinear influence of temperature on the resistance is experimentally determined for the exemplary planar sensors. Based on these results, using first–order and hybrid linear–exponential approximations, the analytical formulae are derived. Additionally, the device to measure an average temperature from several measuring surfaces is considered. Since geometry of the sensor can be designed utilizing presented approach and printed by applying fused deposition modeling, the functional device can be customized to individual needs.

The influence of the trailing edge angle of the micro centrifugal impeller on the performance of the centrifugal compressor

2021 ◽  
pp. 1-15
Author(s):  
Xu Yu-dong ◽  
Li Cong ◽  
Lv Qiong-ying ◽  
Zhang Xin-ming ◽  
Mu Guo-zhen
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Centrifugal Impeller ◽  
Centrifugal Compressors ◽  
Trailing Edge ◽  
Sweep Angle ◽  
Impeller Blade ◽  
Bending Angle ◽  
Edge Angle ◽  
Isentropic Efficiency

In order to study the effect of the trailing edge sweep angle of the centrifugal impeller on the aerodynamic performance of the centrifugal compressor, 6 groups of centrifugal impellers with different bending angles and 5 groups of different inclination angles were designed to achieve different impeller blade trailing edge angle. The computational fluid dynamics (CFD) method was used to simulate and analyze the flow field of centrifugal compressors with different blade shapes under design conditions. The research results show that for transonic micro centrifugal compressors, changing the blade trailing edge sweep angle can improve the compressor’s isentropic efficiency and pressure ratio. The pressure ratio of the compressor shows a trend of increasing first and then decreasing with the increase of the blade bending angle. When the blade bending angle is 45°, the pressure ratio of the centrifugal compressor reaches a maximum of 1.69, and the isentropic efficiency is 67.3%. But changing the inclination angle of the blade trailing edge has little effect on the isentropic efficiency and pressure ratio. The sweep angle of blade trailing edge is an effective method to improve its isentropic efficiency and pressure ratio. This analysis method provides a reference for the rational selection of the blade trailing edge angle, and provides a reference for the design of micro centrifugal compressors under high Reynolds numbers.

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