Evaluation of Grid Convergence and Turbulence Model Constant Changes for the Airfoil Flow Simulation

2007 ◽  
Author(s):  
Myung Rhee
Keyword(s):  
Turbulence Model ◽  
Flow Simulation ◽  
Grid Convergence ◽  
Airfoil Flow

scholarly journals Flow Simulation And Performance Analysis Of Centrifugal Compressor Using Cfd_Tool

2021 ◽  
Vol 23 (11) ◽  
pp. 693-703
Author(s):  
Tesfaye Barza ◽  
◽  
G. Lakshmikanth ◽  
Keyword(s):  
Performance Analysis ◽  
Pressure Distribution ◽  
Turbulence Model ◽  
Centrifugal Compressor ◽  
Flow Simulation ◽  
Internal Flow ◽  
Design System ◽  
Turbulent Fluid Flow ◽  
Compressor Impeller ◽  
And Performance

This paper is concerned the flow simulation and performance analysis of the Centrifugal Compressor Using CFD – Tool. The complex internal flow of centrifugal compressor can be well analyzed, and the unique design system needs to be developed. It should be early to use the interface and also flexible for input and output. A 3-D flow simulation of turbulent – fluid flow is presented to visualize the flow pattern in-terms of velocity, streamline and pressure distribution on the blade surface are graphically interpreted. The standard K- e turbulence model and the simple model algorithm were chosen for turbulence model and pressure distribution well determined. The simulation was steady Heat transfer and moving reference frame was used to consider the impeller interaction under high resolution. Furthermore, A computational Fluid Dynamics (CFD) 3-D simulation is done to analyze the impeller head and efficiency required of centrifugal compressor. The impeller is rotated for a constant revolution and mass flow rate, in this study initially the geometry of centrifugal compressor impeller is created by an ANSYS Vista CCD, and the Blade modeller done by Bladegen, Finally, CFD analysis was performed in ANSYS CFX using the ANSYS Turbo grid meshing tool. According to the analysis, as the number of impeller blades increases, so does the value of the head and power imparted, as well as the impeller’s efficiency.

Hybrid Turbulence Model Simulations of Partially Stalled Airfoil Flow

AIAA Journal ◽  
2016 ◽  
Vol 54 (4) ◽  
pp. 1220-1234 ◽  
Author(s):  
A. Gross ◽  
H. F. Fasel
Keyword(s):  
Turbulence Model ◽  
Model Simulations ◽  
Airfoil Flow

scholarly journals Assessments ofk-kLTurbulence Model Based on Menter’s Modification to Rotta’s Two-Equation Model

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Khaled S. Abdol-Hamid
Keyword(s):  
Turbulence Model ◽  
Equation Model ◽  
Navier Stokes ◽  
Length Scale ◽  
Turbulent Length Scale ◽  
Eddy Simulation ◽  
Grid Convergence ◽  
Large Eddy ◽  
Natural Inclusion ◽  
Better Than

The main objective of this paper is to construct a turbulence model with a more reliable second equation simulating length scale. In the present paper, we assess the length scale equation based on Menter’s modification to Rotta’s two-equation model. Rotta shows that a reliable second equation can be formed in an exact transport equation from the turbulent length scale and kinetic energy. Rotta’s equation is well suited for a term-by-term modeling and shows some interesting features compared to other approaches. The most important difference is that the formulation leads to a natural inclusion of higher order velocity derivatives into the source terms of the scale equation, which has the potential to enhance the capability of Reynolds-averaged Navier-Stokes to simulate unsteady flows. The model is implemented in the CFD solver with complete formulation, usage methodology, and validation examples to demonstrate its capabilities. The detailed studies include grid convergence. Near-wall and shear flows cases are documented and compared with experimental and large eddy simulation data. The results from this formulation are as good or better than the well-known shear stress turbulence model and much better thank-εresults. Overall, the study provides useful insights into the model capability in predicting attached and separated flows.

scholarly journals Transonic Airfoil Flow Simulation. Part I: Mesh Generation and Inviscid Method

2010 ◽  
Vol 2 (2) ◽  
pp. 50-56
Author(s):  
FRUNZULICĂ Florin ◽  
◽  
DUMITRESCU Horia ◽  
DUMITRACHE Alexandru ◽  
CARDOS Vladimir
Keyword(s):  
Mesh Generation ◽  
Flow Simulation ◽  
Airfoil Flow ◽  
Transonic Airfoil

Flow Simulation and Diagnosis Through Hydraulic Turbines Using a RNG k-ω Turbulence Model

2010 ◽  
Author(s):  
Shuhong Liu ◽  
Xiaojing Wu ◽  
Yulin Wu
Keyword(s):  
Turbulence Model ◽  
Large Scale ◽  
Flow Behavior ◽  
Flow Simulation ◽  
Hydraulic Turbine ◽  
Francis Turbine ◽  
Design Stage ◽  
Hydro Power ◽  
Large Power ◽  
Power Stations

Francis turbine is widely employed in large scale hydro-power stations in the world with main characteristics of efficiency, stability and cavitation. In practical establishment, each large power station must develop a new Francis turbine for its special natural condition and requirement, such as higher efficiency for utilization of natural resources. CFD has been developed greatly and helped a lot in hydraulic design stage of the turbine. In this paper, firstly, a new RNG k–ω turbulence model is proposed based on the RNG k–ε model, which brings the nonlinear term of the mean fluid flow transition to the ω equation in the original k–ω model. And, this RNG k–ω model has been used to predict the energy performances for Francis turbine. Then, the flow diagnosis method in the turbine runner based on vorticity parameters is presented, following the detailed flow behavior revealed. Finally, the simulation results for different model Francis turbines have been compared and analyzed for optimizing the energy performances of the turbine. The model test results indicate that the efficiency of hydraulic turbine has been improved from 93.6% to 94.5%.

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