scholarly journals Selection of Parameters for Blade-to-blade Finite-volume Mesh for CFD Simulation of Axial Turbines

2018 ◽  
Vol 220 ◽  
pp. 03003 ◽  
Author(s):  
Grigorii Popov ◽  
Valery Matveev ◽  
Oleg Baturin ◽  
Yulia Novikova ◽  
Andrey Volkov
Keyword(s):  
Numerical Simulation ◽  
Finite Volume ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Turbulence Models ◽  
Model Parameters ◽  
Working Process ◽  
Axial Turbines ◽  
Volume Mesh ◽  
Selection Of

This paper describes the first part of the global work done by the authors aimed at finding the best settings for a numerical model for the calculations of axial uncooled turbines using RANS approach. The authors studied more than 80 papers published over the past 5 years in the examined field. Their analysis did not allow to identify unified recommendations for the creation of numerical models. The selection of model parameters is usually motivated by general considerations of numerical simulation, which follow from the method. In none of the papers the selection of parameters is correlated with the structure of the flow in the turbine. Many specific simulation issues were not covered at all. For the research, more than 1000 models of full-size axial turbines (including multistage turbines) and their elements were created. They differed in the number, size, parameters of the elements of finite volume meshes, in turbulence models, in the degree of simplification. The results were compared with the experimental data. As a result, the following was obtained: 1. A method for developing and optimizing the working process of turbines using numerical simulation based on the RANS approach is proposed. The search for the optimal turbine configuration is carried out using light computational models, which are based on the simplified channel geometry and the finite volume mesh. Their application makes it possible to reliably find the optimal turbine configuration 2.8 times faster. The characteristics of the selected variants are verified with the help of verification models that consider the real geometry of the channels and have a minimum error. 2. Recommendations are given on the selection of parameters for finite volume meshes and the selection of turbulence models for numerical models of the working process of axial turbines designed to perform optimization and verification calculations.

scholarly journals Selection of Parameters for 3D Finite-volume Mesh for CFD Simulation of Axial Turbines

2018 ◽  
Vol 220 ◽  
pp. 07001 ◽  
Author(s):  
Grigorii Popov ◽  
Valery Matveev ◽  
Oleg Baturin ◽  
Julia Novikova ◽  
Daria Kolmakova ◽  
...  
Keyword(s):  
Finite Volume ◽  
Computational Models ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Turbulence Models ◽  
Working Process ◽  
Global Work ◽  
Axial Turbines ◽  
Volume Mesh ◽  
Selection Of

This article describes the second part of the global work done by the authors aimed at finding the best settings for a numerical model for calculations of axial uncooled turbines using the RANS approach. For the research, more than 1000 models of full-size axial turbines (including multistage turbines) and their elements were created. They differed in the number, size, parameters of the elements of finite volume meshes, in turbulence models, in the degree of simplification. The results were compared with the experimental data. As a result, the following was obtained: 1. A method for developing and optimizing the working process of turbines using numerical simulation based on the RANS approach is proposed. The search for the optimal turbine configuration is carried out using light computational models, which are based on the simplified channel geometry and the finite volume mesh. Their application makes it possible to reliably find the optimal turbine configuration 2.8 times faster. The characteristics of the selected variants are verified with the help of verification models that consider the real geometry of the channels and have a minimum error. 2. Recommendations are given on the selection of parameters for finite volume meshes and the selection of turbulence models for numerical models of the working process of axial turbines designed to perform optimization and verification calculations.

scholarly journals Flow simulation in air intake system of gas turbine

2021 ◽  
Vol 23 (4) ◽  
pp. 66-83
Author(s):  
V. L. Blinov ◽  
I. S. Zubkov ◽  
Yu. M. Brodov ◽  
B. E. Murmanskij
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Numerical Models ◽  
Flow Simulation ◽  
Technical Condition ◽  
Model Parameters ◽  
Intake System ◽  
Performance Factors ◽  
Air Intake

THE PURPOSE. To study the issues of air intake system’s performance as the part of the gas turbines. To estimate the possibility of modeling different performance factors of air intake systems with numerical simulation methods. To develop the recommendations of setting up the grid and the numerical models for researches in air intake system’s performance and assessing the technical condition of elements of it. METHODS. The main method, which was used during the whole study, is computational fluid dynamics with usage of CAE-systems.RESULTS. During the study the recommendations for setting up the numerical model were developed. Such factors as grid model parameters, roughness scale, pressure drop in elements of air intake system and some more were investigated. The method for heat exchanger’s performance simulation were created for modeling the air temperature raising. CONCLUSION. The air intake system’s performance analysis becomes one of the actual topics for research because of the high demands of gas turbines to air, which is used in its annulus. The main part of these researches is in analysis of dangerous regimes of work (e.g. the icing process of annulus elements) or in assessing technical condition of air intake systems and its influence to the gas turbine as a whole. The developed method of numerical simulation allows to get the adequate results with low requirements for computational resources. Also this method allows to model the heat exchanger performance and study its defects’ influence to the performance of air intake system as a whole. 

The Influence of Turbulence Model Selection and Leakage Considerations on CFD Simulation Results for a Centrifugal Pump

2012 ◽  
Vol 594-597 ◽  
pp. 1940-1944
Author(s):  
Han Liu ◽  
Hua Chen Pan
Keyword(s):  
Numerical Simulation ◽  
Model Selection ◽  
Centrifugal Pump ◽  
Turbulence Model ◽  
Cfd Simulation ◽  
Turbulence Models ◽  
Leakage Flow ◽  
Pump Performance ◽  
Simulation Results

A commercial CFD software was used to simulate and predict a centrifugal pump performance. In this paper，the influences on the numerical simulation results using different turbulence models and different leakage flow assumptions were studied. The simulations are based on RANS with the and SST turbulence models. It is found that SST turbulence is better. Also the influence of the leakage flow was studied.

scholarly journals Improving the accuracy of Numerical Simulation of the Working Process of DieselEngine

2020 ◽  
Vol 26 (1) ◽  
pp. 03-26
Author(s):  
Сергей Иванович Горб
Keyword(s):  
Numerical Simulation ◽  
Numerical Modeling ◽  
Work Processes ◽  
Working Process ◽  
Alternative Models ◽  
Selection Of

The method of numerical modeling provides a modular principle for describing work processes, that allows usage of alternative models of individual processes. When choosing models, an intuitive approach prevails in the selection of design expressions for individual processes. This inevitably affects the accuracy of solving practical problems. In connection with the foregoing, the task was assigned to analyze the effectiveness of alternative models that can be used in the method of numerical modeling of diesel work processes.

scholarly journals A CRITICAL REVIEW OF MODELS USED IN NUMERICAL SIMULATION OF ELECTROSTATIC PRECIPITATORS

2016 ◽  
Vol 6 (4) ◽  
pp. 9-17
Author(s):  
Zhuangbo Feng ◽  
Long Zhengwei ◽  
Kazimierz Adamiak
Keyword(s):  
Numerical Simulation ◽  
High Efficiency ◽  
Numerical Models ◽  
Physical Processes ◽  
Flexible Tool ◽  
Industry Applications ◽  
Low Costs ◽  
Electrostatic Precipitators ◽  
Flow Particle ◽  
Selection Of

The electrostatic precipitators (ESP) have been drawing more and more attention due to their high efficiency and low costs. Numerical simulation is a powerful, economical and flexible tool to design ESP for industry applications. This review summarizes the available numerical models to simulate different physical processes in ESP, including ionized electric field, air flow, particle charging and motion. It has been confirmed that the available models could provide acceptable results and the computing requirements are affordable in industry applications. The coupling between different physical processes can also be considered in simulation. However, there are still some problems not solved, such as selection of a suitable turbulence model in EHD simulation and the coupling criteria. The future study should focus on these issues. This review also includes new types of ESP developed in recent years, such as dielectric barrier discharge (DBD) ESP and corona assisted fibrous filter. These new types of ESP have had high efficiency and low energy consumption. Even though nearly all new ESP types can be modeled using the available numerical models, the most challenging issue is the DBD simulation.

scholarly journals REVIEW OF CFD SIMULATION OF OXY-COAL COMBUSTION FOR ELETRICAL POWER GENERATION: OPPORTUNITIES AND CHALLENGES

2016 ◽  
Vol 15 (2) ◽  
pp. 76
Author(s):  
F. S. Nascimento ◽  
M. A. R. Nascimento ◽  
C. J. R. Coronado ◽  
L. O. Rodrigues ◽  
J. A. Carvalho Jr ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Combustion ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Cost Savings ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Simulation Techniques ◽  
Reduction Of Co2 ◽  
Physical Phenomena

The oxy-combustion has generated significant interested for reduction of CO2 emission when the fossil fuel is coal, due to simplification on the separation process of CO2 from the flue gas, it can be more easily stored in reservoir. The CFD numerical simulation techniques in oxy-coal combustion has the potential to contribute to designers in cost savings and reduced computational time; Furthermore, such techniques also provide a robust tool for better understanding and description of the aerothermodynamics processes involved, as well as, aiding the design of most efficient furnaces. However, to obtain representative results of the physical phenomena, the numerical models employed by CFD needs to be suitable for oxy-coal combustion. So, the aim of the paper is to carry out a review of the recent models that are being used for turbulence, combustion and pollutant emissions. Moreover, it is shown a comparison of different results obtained in the numerical simulation of oxy-coal combustion among new models, existing models and experiments. The analysis of the models and experiments shows that the challenges that are still being faced to obtain better accuracy of numerical simulation results. Improvements in the models for oxy-coal combustion can be seen like potential opportunities to investigate and optimize the process that occur in the combustion.

Verification and Validation of CFD Uncertainty Analysis Based on SST K-ω Model

2020 ◽  
Author(s):  
Li Zhang ◽  
Weimin Chen ◽  
Jianting Chen ◽  
Chuanming Zhou
Keyword(s):  
Numerical Simulation ◽  
Uncertainty Analysis ◽  
Cfd Simulation ◽  
Numerical Results ◽  
Verification And Validation ◽  
Ship Model ◽  
The Past ◽  
Mesh Density ◽  
Simulation Results ◽  
Selection Of

Abstract CFD uncertainty analysis is a process to quantify the accuracy of numerical simulation results, and it is also a research hotspot in the past decades. ITTC(2017) requires uncertainty analysis of ship CFD simulation results, that is, verification and validation. In this paper, with reference to the recommended procedures by ITTC, the uncertainty of the CFD numerical simulation results of ship model resistance was analyzed. Based on the SST k-ω turbulence model, the Y+ values near the wall were set to 60,120,240, respectively. And for each and Y+ value, three different sets of grid densities were set respectively, and the uncertainty was analyzed. The results show that: 1) the results of Y+ at 60 and 120 were not validated, and the results at 240 was validated, 2) the selection of Y+ value has a significant effect on the numerical results, 3) increasing the mesh density can make the result converge, but it is not sure to get the result with the least error. Through the uncertainty analysis of CFD results, it is helpful to find a method to improve the accuracy of the numerical results.

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