Axial Compressor CFD

This study shows smooth workflow of performing a complex CFD analysis of NASA axial compressor Rotor 67 using TCFD®

TCFD® Main Page - Download This Tutorial - Compressor Results Report


Turbomachinery CFD GUI intrface Axial Compressor


TCFD® is automated workflow


CFD SUPPORT introduces the new generation of CFD simulations. TCFD® brings an extreme increase of productivity to CFD simulations. TCFD® is extremely popular project, because it successfully merged benefits of an open-source (perpetual, unlimited users, jobs, and cores, customizable, ...) with benefits of commercial codes (professional support, well tested, ready for the industry, robust, accurate, automated, GUI, ...).

TCFD - Turbomachinery CFD scheme automated workflow

TCFD® is fully automated, it can run the whole workflow by a single command: data input, new case is written down, mesh is created, case is set-up, case is simulated, results are evaluated and the results report is written down. Both GUI and batch mode. Data in - data out. TCFD® is mainly focused on supporting the engineers in their real value added work. TCFD® is fully automated and the beauty of TCFD® is that it is the user who decides how deep to dive into a CFD or not at all. And all the options remain open at the same time.


The input data

The NASA Rotor 67 axial compressor was simulated. The measurement data is available for results comparison. Rotor has 22 blades - periodic segment of single one blade region is computed. The surface model data in .stl file format together with physical inputs are loaded in TCFD®. Other option would be loading an external mesh in OpenFOAM® mesh format, or loading an MSH mesh format (Fluent mesh format). This CFD methodology employs a multi component approach, which means the model is split into a certain number of regions. In TCFD® each region can have its own mesh and individual meshes comunicate via interfaces.

Axial Compressor Segment Tutorial Pressure Z- View NASA Rotor 67 CFD      Axial Compressor Segment Tutorial Pressure any View NASA Rotor 67 CFD      Axial Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD



Easy to test the mesh sensitivity

In practise the rough mesh with no boundary layer (CPU time: 4 core*hours/single point) can give the same results as the fine mesh with boundary layer (CPU time: 20 core*hour/point). So finally, the rough mesh effect can eliminate the lack of boudary layer. Anyway, with fully automated workflow it is easy to make many tests to callibrate to actual machine.



Turbomachinery CFD GUI intrface Axial Compressor


The component graph

Any project simulated in TCFD® has its component graph. The component graph shows how the components are organized - the model topology. What is the inlet, the outlet and how the components are connected via interfaces.


TCFD manifold tcfd tutorial component graph


CFD Simulation Set-up

  • Compressible flow model
  • Steady-state flow model
  • Medium: Air
  • BEP Pressure ratio: ΔpTot = 1.66 [-]
  • Temperature at inlet: T = 25 [ºC]
  • Viscosity: μ = 1.831e-5 [Pa.s]
  • Rotation speed: 16043 [RPM]
  • BEP Mass Flow Rate: 33 [kg/s]
  • Interface: None
  • Turbulence Model: k-ω SST
  • Mesh: snappyHexMesh, hexadominant
  • Mesh Cells: 463938
  • Mesh Average y+ (full/segment): 112 [-]
  • CPU time (per point): 24 [core.hours]

For more details of CFD Simulation Set-up see TCFD® Manual.


Running CFD Simulation

The simulation can be run on any number of parallel processors. Immediately after the simulation is started, the user can follow the progress of all the important quantities in a HTML report: flow rates, residuals, efficiency, torque, pressure difference and many others. These run-time functions give the user valuable information of the simulation convergence and also the availability to stop the simulation before its expected end.

Residuals Convergence OpenFOAM Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD        Pressure Ratio Axial Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD

The workflow computes complete characteristics point by point.

Efficiency Plot Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD        Torque Plot Axial Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD


Every simulation performed in TCFD® has its report in web responsive .html and pdf format: Axial Compressor Simulation Report Example.




Visual Postprocessing using Turbo Blade Post

The simulation results are examined in ParaView. ParaView is CFD postprocessing tool providing all standard features for analyzing CFD data.

ParaView Contour Axial Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD      Paraview TreamTraces Axial Compressor Segment Tutorial Pressure Z+ View NASA Rotor 67 CFD

CFD Support developed a special extension to ParaView for visual postprocessing rotating machinery: Turbo Blade Post, which is special set of filters for ParaView to enable for example blade-to-blade view, or meridional average. Turbo Blade Post detailed manual is available on-line: Turbo Blade Post Manual

10% Blade to blade slice Axial Compressor NASA Rotor 67 CFD      20% Blade to blade slice Axial Compressor NASA Rotor 67 CFD      50% Blade to blade slice Axial Compressor NASA Rotor 67 CFD      80% Blade to blade slice Axial Compressor NASA Rotor 67 CFD      90% Blade to blade slice Axial Compressor NASA Rotor 67 CFD

Blade to blade view. Within the Turbo Blade Post the impeller mesh can be unwrapped to be able to slice it. The computed quantities are displayed at the certain radial coordinate - anywhere along the blade height. With such a unwrapped mesh it is also possible to plot all the quantities along the blade height and also plot quantities around the blade surface, etc.


Turbo Blade Post Blade to blade View Axial Compressor NASA Rotor 67 CFD

Another Turbo Blade Post function is the Meridional Average which creates a meridional plane of circumferential averages of all simulated quantities.

Meridional Average Front Pressure Axial Compressor NASA Rotor 67 CFD      Meridional Average Back Pressure Axial Compressor NASA Rotor 67 CFD



See also other TCFD® simulation examples:

Axial Pump
Centrifugal Pump
Axial Fan
Centrifugal Fan
Axial Compressor
Centrifugal Compressor
Axial Turbine
Radial Turbine
Francis Turbine
Kaplan Turbine
Manifold
Ship Hull Propeller
Valve
Wind Turbine
Valve
Hydraulic Valve
Double Rotor Fan
DrivAer Car Model


Please contact us for further information.





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