TURBODYNA: Centrifugal/Centripetal Turbomachinery Dynamic Simulator and Its Application on a Mixed Flow Turbine

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Bijie Yang ◽  
Ricardo Martinez-Botas
Keyword(s):  
Performance Prediction ◽  
Three Dimensional ◽  
Response Assessment ◽  
System Response ◽  
One Dimensional ◽  
1D Modeling ◽  
Dynamic Simulator ◽  
Computational Fluid Dynamics Cfd ◽  
Unsteady Performance ◽  
Rotor Mass

Abstract One-dimensional (1D) modeling is crucial for turbomachinery unsteady performance prediction and system response assessment. The purpose of the paper is to describe a newly developed 1D modeling (turbomachinery dynamic simulator (TURBODYNA)) for turbomachinery. Different from classic 1D modeling, in TURBODYNA, rotor has been meshed and its unsteadiness due to flow field timescale is considered. Instead of direct using of performances maps, source terms are added in Euler equation set to simulate the rotor. By comparing 1D modeling with three-dimensional (3D) computational fluid dynamics (CFD) results, it shows that rotor unsteadiness is indispensable for a better prediction. In addition, different variables response to pulse differently. In the rotor, mass flow is close to quasi-steady while entropy is significantly unsteady. TURBODYNA can capture these features correctly and provide an accurate prediction on pressure wave transportation.

TURBODYNA: Centrifugal/Centripetal Turbomachinery Dynamic Simulator and its Application on a Mixed Flow Turbine

2019 ◽  
Author(s):  
Bijie Yang ◽  
Ricardo Martinez-Botas
Keyword(s):  
Flow Field ◽  
Performance Prediction ◽  
Pressure Wave ◽  
Response Assessment ◽  
System Response ◽  
Mixed Flow ◽  
Dynamic Simulator ◽  
Unsteady Performance ◽  
1D Modelling ◽  
Rotor Mass

Abstract 1D modelling is crucial for turbomachinery unsteady performance prediction and system response assessment. The purpose of the paper is to describe a newly developed 1D modelling (TURBODYNA) for turbomachinery. Different from classic 1D modelling, in TURBODYNA, rotor has been meshed and its unsteadiness due to flow field time scale is considered. Instead of direct using of performances maps, source terms are added in Euler equation set to simulate the rotor. By comparing 1D modelling with 3D CFD results, It shows that rotor unsteadiness is indispensable for a better prediction. In addition, different variables response to pulse differently. In the rotor, mass flow is close to quasi-steady while entropy is significantly unsteady. TURBODYNA can capture these features correctly and provide an accurate prediction on pressure wave transportation.

Improving a one-dimensional centrifugal compressor performance prediction method

2005 ◽  
Vol 219 (8) ◽  
pp. 653-659 ◽  
Author(s):  
E Swain
Keyword(s):  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Prediction Method ◽  
Compressor Cascade ◽  
One Dimensional ◽  
Compressor Performance ◽  
Cfd Analyses

A one-dimensional centrifugal compressor performance prediction technique that has been available for some time is updated as a result of extracting the component performance from three-dimensional computational fluid dynamic (CFD) analyses. Confidence in the CFD results is provided by comparison of overall performance for one of the compressor examples. The extracted impeller characteristic is compared with the original impeller loss model, and this indicated that some improvement was desirable. The position of least impeller loss was determined using a traditional axial compressor cascade method, and suitable algebraic expressions were derived to match the CFD data. The merit of the approach lies with the relative ease that CFD component performance currently can be achieved and adjusting one-dimensional methods to agree with the CFD-derived models.

A Generalized Computational Fluid Dynamics Approach for Journal Bearing Performance Prediction

1995 ◽  
Vol 209 (2) ◽  
pp. 99-108 ◽  
Author(s):  
P G Tucker ◽  
P S Keogh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Surface Temperature ◽  
Performance Prediction ◽  
Reynolds Equation ◽  
Three Dimensional ◽  
Rotation Effect ◽  
Performance Predictions ◽  
Computational Fluid Dynamics Cfd ◽  
Shaft Surface

The use of computational fluid dynamics (CFD) techniques enables performance predictions of bearing designs to be made when the usual operating assumptions of the Reynolds equation Jail to hold. This paper addresses the application of a full three-dimensional thermohydrodynamic CFD approach to journal bearings. The journal/shaft may extend beyond the bearing length and the rotation effect is accounted for in the thermal transport process. A circumferentially uniform shaft surface temperature is not assumed. Cavitation modelling is based on averaged lubricant/vapour properties and does not set pressures directly, allowing sub-ambient pressures to be predicted. Lubricant inlet grooves are incorporated with conservation of mass and the possibility of backflow. The modelling is validated against published experimental work on fully circumferential, single inlet and two-inlet circular bore bearings. The predicted and experimental results are in general agreement, although the predicted cyclic variation of journal surface temperature is less than the experimental value. However, an assumption in the predictions was of a non-orbiting journal. The techniques developed may, in principle, be extended to the orbiting journal case providing a dynamic cavitation model can be formulated.

ACOUSTIC ATTENUATION CHARACTERISTICS OF STRAIGHT-THROUGH PERFORATED TUBE SILENCERS AND RESONATORS

2008 ◽  
Vol 16 (03) ◽  
pp. 361-379 ◽  
Author(s):  
Z. L. JI
Keyword(s):  
Performance Prediction ◽  
Transmission Loss ◽  
Three Dimensional ◽  
Geometrical Parameters ◽  
Mean Flow ◽  
Acoustic Attenuation ◽  
One Dimensional ◽  
The One ◽  
Attenuation Characteristics ◽  
Perforated Tube

The one-dimensional analytical solutions are derived and three-dimensional substructure boundary element approaches are developed to predict and analyze the acoustic attenuation characteristics of straight-through perforated tube silencers and folded resonators without mean flow, as well as to examine the effect of nonplanar waves in the silencers and resonators on the acoustic attenuation performance. Comparisons of transmission loss predictions with the experimental results for prototype straight-through perforated tube silencers demonstrated that the three-dimensional approach is needed for accurate acoustic attenuation performance prediction at higher frequencies, while the simple one-dimensional theory is sufficient at lower frequencies. The BEM is then used to investigate the effects of geometrical parameters on the acoustic attenuation characteristics of straight-through perforated tube silencers and folded resonators in detail.

Numerical Modeling of Some Parameters for Performance Prediction of Centrifugal Impellers

2000 ◽  
Author(s):  
JongSik Oh ◽  
KoonSup Oh
Keyword(s):  
Turbulent Flows ◽  
Performance Prediction ◽  
Effective Means ◽  
Three Dimensional ◽  
Cfd Analysis ◽  
One Dimensional ◽  
Engineering Models ◽  
Time Marching ◽  
And Diffusion ◽  
Marching Method

The numerical results of a CFD analysis for 5 impellers are presented and discussed to generate simple correlations for the slip factors and the aerodynamic exit blockages of centrifugal compressors. The purpose of the analysis and modeling is to supply an effective means of estimating both parameters used in the meanline performance prediction stage, only in the agile engineering sense. A finite volume time marching method was used in the analysis of three dimensional compressible turbulent flows. To generate one dimensional representative values from the three dimensional results, a mass-averaged concept was used on each impeller exit plane. The Wiesner’s slip factor was found to fail to predict accurate level of values and also the trend of variation, when the flow rate was changed, especially in case of backswept impellers. Aerodynamic blockage at the impeller exit was also found to vary with the flow rates, the blade exit angle and diffusion ratio. Some useful engineering models of both parameters were suggested to improve the current level of prediction for the impeller exit performance.

scholarly journals Study of Unsteady Airflow in Muffler and Air Box Equivalent Geometries

2013 ◽  
Author(s):  
Nicolas-Ivan Hatat ◽  
François Lormier ◽  
David Chalet ◽  
Pascal Chesse
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Internal Combustion ◽  
Physical Models ◽  
One Dimensional ◽  
1D Modeling ◽  
Air Intake ◽  
And Performance

The Internal Combustion Engines (ICE) are inherently sources of the flow’s unsteadiness in the intake and exhaust ducts. Unsteady flow has a direct impact on the engine’s behavior and performance by influencing the filling and emptying of the cylinder. Air intake boxes as well as muffler geometries, which are very commonly used on the two-wheeled vehicles, have an impact on pressure levels and so, on air filling and performances levels. Thus, the purpose of this paper is to identify and analyze different typical geometries of these elements (air box and muffler) by comparing the test bench results with those obtained by 3D and 1D calculations. In this way, it is possible to establish a methodology for modeling the air box and muffler based on experimental tests and the development of 3D and then 1D model. In a beginning, studies consist in describing the geometry of the air box and muffler using a combination of tubes and simple volumes. During one-dimensional simulations, the gases properties in a volume must be calculated taking into account a method of filling and emptying. Under transient conditions, the pipe element is considered essentially as one-dimensional. The gas dynamic is described by a system of equations: the equations of continuity, momentum and energy. In the three-dimensional case, all tubes and volumes are meshed and solved using various physical models, equations and hypotheses that will be detailed subsequently. The study is performed on a shock tube bench. One of the main points is that this type of experimental test allows to test easily different pressure ratios, different geometries and to measure direct and inverse flow. In this way, the propagation of a shock wave is studied in our different geometries and is compared to the pressure signals obtained with 1D and 3D simulations. Once the 1D modeling is obtained, it must be validated in order to be applied in a simulation for Internal Combustion Engine. Validation will be done by direct comparison of results at each stage to ensure that the models and assumptions used in the calculations are correct.

scholarly journals Design, Plant Test and CFD Calculation of a Turbocharger for a Low-Speed Engine

2020 ◽  
Vol 10 (23) ◽  
pp. 8344
Author(s):  
Aleksey Borovkov ◽  
Igor Voinov ◽  
Yuri Galerkin ◽  
Roman Kaminsky ◽  
Aleksandr Drozdov ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Three Dimensional ◽  
Significant Discrepancy ◽  
One Dimensional ◽  
Peter The Great ◽  
Plant Test ◽  
Computational Fluid Dynamics Cfd ◽  
The Mathematical Model ◽  
Speed Engine ◽  
Good Agreement

Various approaches and techniques are used to design centrifugal compressors. These are engineering one-dimensional and quasi-three-dimensional programs, as well as CFD Computational Fluid Dynamics (CFD) programs. The final judgment about the effectiveness of the design is given by testing the compressor or its model. A centrifugal compressor for an internal combustion engine turbocharger was designed jointly by the Research Laboratory “Gas Dynamics of Turbomachines” of Peter the Great St. Petersburg Polytechnic University (SPbPU) and RPA (Research and Production Association) “Turbotekhnika”. To check its dimensionless characteristics, the compressor was tested with two geometrically similar impellers with a diameter of 175 (TKR 175E) and 140 mm (TKR 140E). The mathematical model of the Universal Modeling Method calculates the efficiency in the design mode for all tests of both compressors with an error of 0.89%, and the efficiency for the entire characteristic with an error of 1.55%. The characteristics of the TKR 140E compressor were calculated using the ANSYS commercial CFD software. For TKR-140E, a significant discrepancy in the value of the efficiency was obtained, but a good agreement in the area of operation, which was not achieved in previous calculations. According to the calculation, the work coefficient is overestimated by 9%, which corresponds to the results of previous calculations by the authors.

Rationalization of Empirical Loss Coefficients and Their Application in One Dimensional Performance Prediction Procedures for Centrifugal Compressors

1978 ◽  
Author(s):  
A. Whitfield
Keyword(s):  
Performance Prediction ◽  
Essential Feature ◽  
Three Dimensional ◽  
Separated Flow ◽  
General Assumption ◽  
Centrifugal Compressors ◽  
Loss Mechanism ◽  
One Dimensional ◽  
Adiabatic Flow ◽  
Dimensional Flow

The flow through centrifugal compressors is often highly separated and fully three-dimensional. Modern computing techniques have not yet provided the ability to predict this three-dimensional separated flow. The design engineer has the need of a relatively simple performance prediction procedure in order to assess the potential of any proposed design. Consequently, a number of performance prediction procedures, with the general assumption of one-dimensional adiabatic flow, have been published. A common and essential feature of all these procedures is the use of empirical parameters in order to expand the one-dimensional flow into a description of the fully three-dimensional flow. These empirical parameters usually describe the loss mechanism and the flow deviation in any duct. Presented in footnote is a one-dimensional procedure which separated the fundamental gas dynamics from the empiricism used. Consequently, it is a relatively simple matter to apply alternative empirical parameters, and, more importantly, it is also possible for the design engineer to readily apply empirical relationships built up from his own experience. Unfortunately, numerous techniques are used to define the losses, and it may be necessary for the design engineer to redefine his own data in terms compatible with the computer program available to him.

Performance Evaluation of a Regenerative Blower for Hydrogen Recirculation Application in Fuel Cell Vehicles

2006 ◽  
Author(s):  
Young-Hoon Kim ◽  
Shin-Hyoung Kang
Keyword(s):  
Fuel Cell ◽  
Performance Prediction ◽  
Three Dimensional ◽  
Prediction Method ◽  
Theoretical Models ◽  
Hydrogen Gas ◽  
Fuel Cell Vehicles ◽  
One Dimensional ◽  
Loss Models ◽  
The One

Regenerative blowers are used for hydrogen gas recirculation application in fuel cell vehicles. In this paper we discuss the performance of theoretical models that describe the complex three dimensional flows in regenerative blowers. A one-dimensional performance prediction code is developed based on theoretical models and loss models. Numerical calculation is also performed using a commercial CFD code to analyze the three dimensional flows in a regenerative blower. The results of numerical analysis are used to evaluate the performance of the designed blower and improve the accuracy of performance prediction by correcting the loss models. The results of performance predictions are compared with measured data of a prototype regenerative blower to validate the one-dimensional performance prediction method.

One Dimensional Modelling for Pulsed Flow Twin-Entry Turbine

2021 ◽  
Author(s):  
Bijie Yang ◽  
Ricardo Martinez-Botas ◽  
Yingxian Xue ◽  
Mingyang Yang
Keyword(s):  
Internal Combustion Engines ◽  
Response Assessment ◽  
System Response ◽  
Mixing Process ◽  
One Dimensional ◽  
Turbine Performance ◽  
Pulsed Flow ◽  
Single Entry ◽  
1D Modelling ◽  
Mixing Problem

Abstract One-dimensional (1D) modelling is critical for turbomachinery unsteady performance prediction and system response assessment of internal combustion engines. This paper uses a novel 1D modelling (TURBODYNA) and proposes two additional features for the application to a twin-entry turbocharger turbine. Compared to single-entry turbines, twin-entry turbines enhance turbocharger transient response and reduce engine exhaust valve overlap periods. However, out-of-phase high frequency pulsating pressure waves lead to an unsteady mixing process from the two flows and pose great challenges to traditional 1D modelling. The present work resolves the mixing problem by directly solving mass, momentum and energy conservation equations during the mixing process instead of applying constant pressure assumption at the limb-rotor joint. Comparisons of TURBODYNA and an experimentally validated CFD suggest that TURBODYNA can not only provide a very good agreement on turbine performance, but also accurately capture unsteady features due to flow field inertial and pressure wave propagation. Levels of accuracy achieved by TURBODYNA have proved superior to traditional 1D modelling on turbine performance and the generality of the current 1D modelling has been explored by extending the application to another turbine featuring distinct characteristics.

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