# DNS 1-5 Storage Format

# HiFi-TURB-DLR rounded step

# Storage Format

The statistical data provided is stored in the vtk format, e.g., filename.vtk [1]. The instantaneous data provided is stored in the XML Parallel vtkUnstructuredGrid format, e.g, filename.pvtu [1]. The Parallel data format does not actually contain any data but references other serial files (Serial vtkUnstructuredGrid) containing the data for each grid partition used for the computation, e.g., filename_partition_number.vtu. Both the .vtk and .vtu files can be easily read through the open-source Paraview software, a multi-platform application for data analysis and visualization [2]. Datasets are delivered as compressed file (.tar.gz).

## Instantaneous data format

The dataset consists of a single .pvtu file per snapshot, directly referencing all the nondimensional variables and their spatial derivatives as well as the node positions. For the sake of handling, the instantaneous data was extracted from a limited region of the computational domain, see Instantaneous data.

Provided variables are:

- natural logarithm of dimensionless pressure, ;
- natural logarithm of dimensionless temperature, ;
- dimensionless velocity component in x-direction, ;
- dimensionless velocity component in y-direction, ;
- dimensionless velocity component in z-direction, .

Here, and .
Spatial derivatives of each variable are named as *variable_di* where i={x,y,z}, e.g., u_dy is the derivative of the first component of the velocity vector with respect to the x-direction.

## Statistical data format

The dataset consists of a set of .vtk files:

*averaged_pressure.vtk*: averaged pressure,*averaged_velocity_i.vtk*: averaged velocity*i*-th component,*Reynolds_stress_ij.vtk*: the 6 components of the Reynolds stress tensor,*Taylor_microscale.vtk*: Taylor microscale,*Kolmogorov_length_scale.vtk*: Kolmogorov length scale,*Kolmogorov_time_scale.vtk*: Kolmogorov time scales,

where and range between 1 and 3 and are alias of (streamwise), (normalwise), (spanwise).

## References

Contributed by: **Francesco Bassi, Alessandro Colombo, Francesco Carlo Massa** — *Università degli studi di Bergamo (UniBG)*

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