Use of Experimental Interstage Performance Data to Obtain Optimum Performance of Multistage Axial Compressors

1962 ◽  
Vol 84 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Laurence E. Brown ◽  
Fred G. Groh
Keyword(s):  
Performance Data ◽  
Focus Attention ◽  
Simple Method ◽  
Axial Compressors ◽  
One Stage ◽  
Performance Map ◽  
Multistage Compressors ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
The Individual

Experimental interstage performance data provide the most useful basis currently available for correction of faults in performance of multistage compressors. However, to describe stage performance adequately requires much more information than the amount needed to describe over-all compressor performance, and to interpret the data requires that all of this information be correlated. Because the wealth of the data may conceal its meaning, some simple method is needed to focus attention on the matching of one stage to another and to the over-all compressor as well. A technique is presented whereby performance of individual stages can be depicted graphically upon the performance map of an over-all multistage compressor. Through this presentation the individual and over-all effects can be examined together. Insight is afforded into performance relationships of one stage to another; and faults can be diagnosed if any exist in the matching, radial or axial, of individual stages. Changes of blade geometry can then be prescribed upon a clear and explicit basis. To illustrate use of the technique, data are presented describing gains that have been achieved experimentally.

scholarly journals Simulation of Compressor Performance Deterioration due to Erosion

1989 ◽  
Author(s):  
W. Tabakoff ◽  
A. N. Lakshminarasimha ◽  
M. Pasin
Keyword(s):  
Fault Model ◽  
Experimental Results ◽  
Performance Tests ◽  
Individual Stage ◽  
One Stage ◽  
Before And After ◽  
Performance Deterioration ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
The Individual

Experimental results obtained from cascades and one stage compressor performance tests before and after erosion were used to test a fault model to represent erosion. This model was implemented on a stage stacking program developed to demonstrate the effect of erosion in a multistage compressor. The effect of the individual stage erosion on the overall compressor performance is also demonstrated.

scholarly journals A New Method for the Prediction of Compressor Performance Maps Using One-Dimensional Row-by-Row Analysis

1995 ◽  
Author(s):  
Magdy S. Attia ◽  
M. Taher Schobeiri
Keyword(s):  
Simple Method ◽  
Design Efficiency ◽  
Turbine Engine ◽  
One Dimensional ◽  
Operational Characteristics ◽  
Performance Map ◽  
High Pressure Stage ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
Point Data

This article presents a new and simple method for the prediction of the compressor performance maps based on the geometry and the design point data. The method accurately calculates the compressor performance map based on a comprehensive one-dimensional row-by-row analysis. Off-design efficiency is determined using a modified diffusion factor and an advanced loss calculation method that allows for the accurate prediction of the operational characteristics of the compressor in the post-stall regime. Three different compressor performance maps are generated for low, intermediate and high pressure stage groups using the geometry of the multistage compressor of a power generation gas turbine engine. The results are compared with the maps obtained from experiment.

The Stacking of Compressor Stage Characteristics to Give an Overall Compressor Performance Map

1962 ◽  
Vol 13 (4) ◽  
pp. 349-367 ◽  
Author(s):  
M. D. C. Doyle ◽  
S. L. Dixon
Keyword(s):  
Axial Compressor ◽  
Compressor Stage ◽  
Individual Stage ◽  
Optimum Performance ◽  
Method Of Calculation ◽  
Multi Stage ◽  
Performance Map ◽  
Compressor Performance ◽  
Overall Performance ◽  
The Individual

SummaryA method of calculation is developed to compute the overall performance of a multi-stage axial compressor, from a knowledge of the individual stage characteristics, by a “stacking” technique. Compressor models are designed and their overall performance calculated. These results are compared to show, qualitatively, the effect of alterations in design and stage performance on overall performance and to find how compressors should be designed for optimum performance.

scholarly journals The Investigation of the Stability for Multistage Axial Compressors

1985 ◽  
Author(s):  
Diyi Tang ◽  
Wenlan Li ◽  
Mengzi Cong
Keyword(s):  
Experimental Data ◽  
Physical Model ◽  
Axial Compressors ◽  
Volume Model ◽  
Multistage Compressors ◽  
Multistage Compressor ◽  
The Stability

The “actuator-delay-volume” is used as a physical model for stages of compressors instead of “actuator-lumped volume” model to predict the stability of multistage compressors. The stall line of a multistage compressor is predicted with these two models respectively. The results of simulation are compared with the experimental data of a compressor rig. In order to identify the investigation, the tests, in which the engine is forced into stall and supplied with distorted inflow, have been conducted. The investigation shows that the model is well improved by incorporating an “inertia link” into the model between the “actuator” and the “lumped volume”.

A Method for Efficient Performance Prediction for Fan and Compressor Stages With Degraded Blades

2015 ◽  
Author(s):  
A. Giebmanns ◽  
R. Schnell ◽  
C. Werner-Spatz
Keyword(s):  
Geometric Parameter ◽  
Leading Edge ◽  
Geometric Parameters ◽  
Accurate Estimation ◽  
Compressor Blades ◽  
Performance Map ◽  
Nonlinear Simulations ◽  
Compressor Performance ◽  
The Individual ◽  
Operating Points

Over service time fan and compressor blades vary in their geometry. Due to the geometric irregularities it is difficult to reliably assess the fan or compressor performance. Therefore, in the present study, a method that allows an efficient and accurate estimation of the performance for fan and compressors with degraded blades is established. In a first step, the blade regions mainly exposed to geometry variations are identified. Then, a simple parameterization that enables to easily describe the blade geometry as well as to independently represent the variations of all relevant geometric parameters is defined. For each geometric parameter (e.g. leading edge shape, rotor clearance gap height), the shifts of the operating points in the performance map due to the geometric variations are calculated. This is done with an adjoint flow solver which simultaneously provides the shifts for all extents of geometric parameter variations. As the geometric parameters are assumed to be independent of each other, the combination of variations in several geometric parameters is estimated by simply adding the shift vectors determined for the individual parameters. The results for a subsonic compressor stage show a significant influence of the variations in the geometric parameters on the compressor performance. As validation with few nonlinear simulations demonstrates, this influence is well predicted by the method presented in this study. The relative deviation of the performance map parameters in the operating points around peak efficiency is less than 0.5 %. Compared to the nonlinear simulations, the numeric effort to determine the influence of seven geometric parameters on the performance map with the method based on adjoint simulations is considerably reduced by a factor of 35. In summary, the results demonstrate the feasibility of the method and encourage its application in an industrial context.

scholarly journals Derivation of Compressor Stage Characteristics, for Accurate Overall Performance Map Prediction

1994 ◽  
Author(s):  
A. Tsalavoutas ◽  
A. Stamatis ◽  
K. Mathioudakis
Keyword(s):  
Optimization Techniques ◽  
Accurate Prediction ◽  
Test Cases ◽  
Initial Stage ◽  
Performance Map ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
Overall Performance ◽  
Compressor Map ◽  
Physical Phenomena

In the present paper a method for deriving stage characteristics, which can provide accurate prediction of a multistage compressor map is presented. The method combines optimization techniques with the principles of stage stacking. The stage characteristics are produced by modifying some initial generic ones, until the desired accuracy in the prediction at selected points on the overall map is achieved. There are several reasons why prediction based on the initial stage characteristics can be inaccurate, the following three being the main ones. The first is due to inaccuracy in the representation of the stage characteristics themselves. The second is due to lack of exact knowledge of the geometric data of the various stages. Finally the third reason consists of the “weak” modelling representation of complex physical phenomena with one dimensional approaches. Therefore, even when the exact stage characteristics are known, this does not guarantee the accurate prediction of the compressor performance. On account of the above, it is preferable to acquire realistic “effective” stage characteristics which can be used for synthesizing overall compressor characteristics and assessing the effects of stage faults. In this paper, both of these aspects are successfully tackled as demonstrated by applying the method to different test cases.

Upgrade of a 16-Stage Industrial Compressor: Part II — Extension of the Analysis Method to the Design Function and Results

2006 ◽  
Author(s):  
Magdy S. Attia
Keyword(s):  
Axial Compressor ◽  
Design Environment ◽  
Axial Compressors ◽  
Performance Targets ◽  
Streamline Curvature ◽  
Multi Stage ◽  
Design Function ◽  
3D Effects ◽  
Compressor Performance ◽  
The Individual

A retrofit package that includes a slightly larger inlet and new, custom diffusion airfoils (CDA) was designed to replace the 16-stage axial compressor. The method used, and presented here, builds on earlier developments and is an extension of the scheme used to predict the compressor performance (Part I). The use of results from single-row 3D CFD, and their implementation into a streamline curvature (Throughflow) code lead to a better understanding of the compressor performance, which in turn lead to a better model of the compressor. This paper shows how the role of this newly developed model has been modified and adapted to the design environment. The 3D CFD results had previously provided a more accurate representation of deviation and losses, particularly at and near the end walls. The Throughflow code, when re-converged for design purposes, generated a much different solution for the individual streamlines than had been previously calculated using correlation or S1S2 analyses. Consequently, the newly generated boundary conditions for designing the individual stream sections, such as inlet and exit Mach numbers and air angles were also quite different. The designer then embarked on tailoring the individual sections to their respective duties under the guidelines of the newly developed method in true custom diffusion fashion. Iterations were conducted to optimize the section and airfoil shapes taking into consideration 3D effects. The end result was a systematic technique for designing multi-stage axial compressors and generating 3D airfoil shapes. The retrofit compressor upgrade package achieved its performance targets and delivered a measured polytropic efficiency of 93.4%.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

Performance Prediction for Automotive Turbocharger Compressors

1975 ◽  
Vol 189 (1) ◽  
pp. 557-565 ◽  
Author(s):  
A. Whitfield ◽  
F. J. Wallace
Keyword(s):  
Performance Prediction ◽  
Flow Analysis ◽  
Compressor Stage ◽  
Thermodynamic Models ◽  
Flow Rates ◽  
Design Point ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Performance Map ◽  
The Individual

A procedure to predict the complete performance map of turbocharger centrifugal compressors is presented. This is based on a one-dimensional flow analysis using existing published loss correlations that were available and thermodynamic models to describe the incidence loss and slip factor variation at flow rates which differ from the design point. To predict the losses within the complete compressor stage using a one-dimensional flow procedure, it is necessary to introduce a number of empirical parameters. The uncertainty associated with these empirical parameters is assessed by studying the effect of varying them upon the individual losses and upon the overall predicted performance.

Compressor Maps and Coupling: Symmetry, Paradox, and Clarity

2021 ◽  
Author(s):  
Benjamin Iwrey
Keyword(s):  
Temperature Ratio ◽  
Independent Variables ◽  
Dependent Variables ◽  
In Series ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
Compressor Map ◽  
Flow Flux ◽  
Operating Points ◽  
Corrected Flow

Abstract The most common compressor map framework, referred to here as the β-framework, will be shown to suffer from limitations that grow more troublesome in the multiple-map environment. When maps are coupled in series in the β-framework, it is very common to find operating points that are physically unrealizable, but these cannot generally be avoided without first generating them. A feasible situation is described in which the β-framework leads to an apparent physical paradox. In the proposed S-framework, the map itself is recast in terms of independent variables (corrected speed and exit corrected flow) and dependent variables (inlet corrected flow and temperature ratio). The propagation of information in map coupling is split into an upstream-marching corrected flow ‘flux’ and a downstream-marching temperature ‘flux’. Finding the equilibrium operating point requires only finding a simple intersection between curves. The S-framework is then developed further into a more compact S’-framework that exhibits a natural set of qualitative symmetries. The S- and S’-frameworks are shown to simplify compressor map expression, resolve the problems shown with the β-framework, and aid intuition with regard to off-design phenomena. The resolution of the paradox using the S’-framework is a new description of multistage compressor performance hysteresis.

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