Computer Graphics Laboratory ETH Zurich

ETH

Data

Numerical Simulations

The following list contains a number of numerical data sets that we released for any use. If you use the data in your publications, please acknowledge the contributors by using the provided citation next to the download links. All data sets are provided in NetCDF format, the Amira format and the VTK format. The NetCDF format is highly recommended, as it contains many useful properties, such as the physical units and the parameters of the simulation (obstacles, viscosity, Reynolds number if available).

2D Unsteady Cylinder Flow with von Karman Vortex Street

Image
Line integral convolution
Image
Vorticity
Image
Finite-time Lyapunov exponent (backward)
Regular grid:NetCDF (440 MB)Amira (460 MB)VTK (448 MB)
Unstructured grid:VTK (4.83 GB)
Citation

Simulation of a viscous 2D flow around a cylinder. The fluid was injected to the left of a channel bounded by solid walls with a slip boundary condition. The simulation was done with Gerris flow solver and was resampled onto a regular grid. In the original simulation, the unstructured grid was adaptively discretized based on the vorticity. Over the course of the simulation, the characteristic von-Karman vortex street is forming. The image on the side shows a later time step, in which the street is fully formed. The vortices move with almost constant speed, except directly in the wake of the obstacle, where they accelerate.

Regular grid resolution (X x Y x T): 640 x 80 x 1501
Simulation domain: [-0.5, 7.5] x [-0.5, 0.5] x [0, 15]
Reynolds Number: 160
Kinematic viscosity: 0.00078125
Obstacle at (0,0) with radius: 0.0625

2D Unsteady Heated Cylinder with Boussinesq Approximation

Image
LIC
Image
Vorticity
Image
FTLE
Regular grid:NetCDF (903 MB)Amira (922 MB)VTK (908 MB)
Unstructured grid:VTK (1.68 GB)
Citation

Simulation of a 2D flow generated by a heated cylinder. To solve the buoyancy problem, the Boussinesq approximation is used. The simulation was done with Gerris flow solver and was resampled onto a regular grid. The turbulent plume contains numerous small vortices that in part rotate around each other.

Grid resolution (X x Y x T): 150 x 450 x 2001
Simulation domain: [-0.5, 0.5] x [-0.5, 2.5] x [0, 20]
Obstacle at (0,-0.15) with radius: 0.0625

2D Unsteady Cylinder Flow Around Corners

Image
Vorticity
Image
Finite-time Lyapunov exponent (backward)
Regular grid:NetCDF (409 MB)Amira (414 MB)VTK (412 MB)
Unstructured grid:VTK (518 MB)
Citation

Simulation of a viscous 2D flow around two cylinders. The fluid was injected to the left of a channel bounded by solid walls with a slip boundary condition. The simulation was done with Gerris flow solver and was resampled onto a regular grid. In the original simulation, the unstructured grid was adaptively discretized based on the vorticity. Initially, a vortex street forms behind the first obstacle, which then flows around two corners. Behind each corner, a standing vortex forms. The latter one blocks half of the flow to the second obstacle, creating a one-sided vortex street.

Regular grid resolution (X x Y x T): 450 x 150 x 1501
Simulation domain: [-0.5, 5.5] x [-0.5, 1.5] x [0, 15]
Reynolds Number: 160
Kinematic viscosity: 0.00078125
Obstacles at (0,0) and (3,1) both with radius: 0.0625

3D Unsteady Half Cylinder Ensemble

Image
Vorticity for Reynolds number: 160
Image
Vorticity for Reynolds number: 320
Image
Vorticity for Reynolds number: 640
Image
Vorticity for Reynolds number: 6400
Re = 160
  Regular grid:  NetCDF (17.7 GB)Amira (18.7 GB)VTK (17.9 GB)
  Unstructured grid:  VTK (1.2 GB)
Re = 320
  Regular grid:  NetCDF (17.6 GB)Amira (18.6 GB)VTK (17.8. GB)
  Unstructured grid:  VTK (1.4 GB)
Re = 640
  Regular grid:  NetCDF (17.6 GB)Amira (18.6 GB)VTK (17.9 GB)
  Unstructured grid:  VTK (1.5 GB)
Re = 6400
  Regular grid:  NetCDF (17.6. GB)Amira (18.6 GB)VTK (17.9 GB)
  Unstructured grid:  VTK (1.9 GB)
Citation

Small ensemble of numerical simulations of an incompressible 3D flow around a half cylinder. Each ensemble member was simulated with a different Reynolds number (Re). The simulations were done with Gerris flow solver and were resampled onto a regular grid. In the original simulation, the unstructured grid was adaptively discretized based on the vorticity. This flow might be useful for ensemble visualization techniques or for tests on flows with varying degree of turbulence.

Regular grid resolution (X x Y x T): 640 x 240 x 80 x 151
Simulation domain: [-0.5, 7.5] x [-1.5, 1.5] x [-0.5, 0.5] x [0, 2]
Reynolds Numbers: 160, 320, 640, 6400

3D Unsteady Research Vessel Tangaroa

Image
Vorticity in wake of the ship
Regular grid:NetCDF (12.5 GB)Amira (13.1 GB)VTK (12.7 GB)
Unstructured grid:VTK (2.1 GB)
Citation

Simulation of an incompressible 3D flow around a CAD model of the research vessel Tangaroa. The simulation was done with Gerris flow solver and a region of interest was resampled onto a regular grid. This is one of the example simulations of Gerris flow solver. In the original simulation, the unstructured grid was adaptively discretized based on the vorticity.

Regular grid resolution (X x Y x T): 300 x 180 x 120 x 201
Simulation domain: [-0.35, 0.65] x [-0.3, 0.3] x [-0.5, -0.3] x [0, 2]

Analytic Vector Fields

It can come in very handy to test algorithms on analytic vector fields. For each analytic data set, the formular of the vector field itself and the first-order partial derivatives are provided in C++, Matlab and Python. For ease of use and testing, the vector fields are sampled onto regular grids, as well.

2D Unsteady Double Gyre

Image
LIC with vorticity
Image
Finite-time Lyapunov exponent
NetCDF (108 MB)Amira (113 MB)VTK (117 MB)
C++ codeMatlab codePython code
Citation

The double gyre is a periodic time-dependent vector field, in which a separating boundary oscillates horizontally between two oppositely rotating vortices. The flow was introduced by Shadden et al. and became the prime benchmark for finite-time Lyapunov exponents. The analytic formular has several parameters that steer magnitude (A), oscillation frequency (omega) and oscillation amplitude (eps). The resampled versions use the standard parameters listed below. The flow is also spatially periodic, which allows variations that contain saddles in the interior of the domain, such as the quad gyre with [0,2] x [-1,1] x [0,10].

Grid resolution (X x Y x T): 256 x 128 x 512
Space-time Domain: [0, 2] x [0, 1] x [0, 10]
Standard parameters: A = 0.1, omega = pi/5, eps = 0.25

2D Unsteady Beads Problem

Image
Vortex corelines in the Beads problem, image from here
NetCDF (775 KB)Amira (13.8 MB)VTK (837 KB)
C++ codeMatlab codePython code
Citation

Wiebel et al. studied particle motion in a rotating petri-dish, which proved to become a challenging benchmark for vortex coreline extraction, since the vortex center is moving on a circular path, which is not covered by Galilean invariant vortex extractors. An analytic approximation to this flow was for instance given by Weinkauf and Theisel, which is provided here. The image on the side shows pathlines that are attracted to the true coreline (blue), compared to a Galilean invariant coreline extraction (green).

Grid resolution (X x Y x T): 128 x 128 x 512
Simulation domain: [-2, 2] x [-2, 2] x [0, 2pi]

2D Unsteady Four Rotating Centers

Image
LIC with vorticity
Image
FTLE
NetCDF (54 MB)Amira (56.3 MB)VTK (57.5 MB)
C++ codeMatlab codePython code
Citation

This analytic data set contains four vortices. The flow is made unsteady by performing a uniform reference frame rotation. User parameters are a scaling factor of the magnitude (scale) and the speed of the reference frame rotation (al_t). The vortex centers are positioned at t=0 at ± 2^(-1/2). The construction of the data set is described here in Section 7.2. This data set is a good benchmark for reference frame invariant flow feature extraction, since simple Galilean invariance is not enough.

Grid resolution (X x Y x T): 128 x 128 x 512
Space-time domain: [-2, 2] x [-2, 2] x [0, 2pi]
Standard parameters: scale = 1, al_t = 1

2D Unsteady Forced-Damped Duffing Oscillator

Image
LIC
Image
FTLE
NetCDF (30.1 MB)Amira (31 MB)VTK (29.9 MB)
C++ codeMatlab codePython code
Citation

This analytic vector field describes the phase space of a duffing oscillator with forcing and damping. For the standard parameters, the vector fields contains a saddle-type periodic orbit.

Grid resolution (X x Y x T): 128 x 128 x 512
Space-time domain: [-2, 2] x [-2, 2] x [0, 4]
Standard parameters: alpha = -0.25, beta = 0.4

2D Unsteady Cylinder Flow (Synthetic)

Image
Line integral convolution
NetCDF (311 MB)Amira (317 MB)VTK (313 MB)
Citation   

This synthetic vector field represents a simple model of a von-Karman vortex street generation and was constructed by Jung, Tel and Ziemniak as co-gradient to a stream function. The obstacle is positioned at (0,0) and has a radius=1. In the LIC image on the side, the flow in the interior of the obstacle has not been set to zero. Note that only two vortices are present at the same time. In the files above, we sampled four periods onto a regular grid.

Grid resolution (X x Y x Z): 450 x 200 x 500
Spatial domain: [-3, 7] x [-2, 2] x [1.107, 5.535]

3D Steady Tornado (Synthetic)

Image
Streamlines from here
Image
Stream surfaces from here
NetCDF (16.9 MB)Amira (17.7 MB)VTK (17.0 MB)
Citation

This synthetic model of a tornado was created by Roger Crawfis and was made available as C code here. We scaled the flow to a larger domain and sampled it onto a regular grid. If higher resolutions are required, simply run the C code.

Grid resolution (X x Y x Z): 128 x 128 x 128
Spatial domain: [-10, 10] x [-10, 10] x [-10, 10]

More Scientific Data Sets

Haven't found the right data set yet? The following list contains a number of pointers.
Point Data
Scalar Fields
Vector Fields

How Can I Read the Data Sets?

In general, NetCDF is the recommend format. Readers exist for almost all languages (C++, Matlab, Python, ...). If you write C++ code and do not want to depend on other libraries, have a look at the Amira reader of Tino Weinkauf here. If you are compiling with VTK anyway, you can use the VTK readers. ParaView should have no problems to open the VTK files.

Let me know if you need help to open the data. We can learn from it and provide more information on this website to also help the next person.

Contribute to This List?

Send me an email at tobias.guenther(at)inf.ethz.ch if you want a link to your data set here or are interested in sharing your data in our repository.