CTRFL research activities result in a variety of databases that may benefit the research of others. Public, restriction free sharing of large datasets remains a data transfer challenge, so simple links to raw data are not feasible. However, if you are interested in using any of the datasets below, please contact us, and we discuss your needs and how we can help. Datasets currently available are described on this page, and additional databases will be added as they become available.

**Multiscalar Mixing DNS Data**

*Overview*

Direct Numerical Simulations of three-component mixing in forced isotropic turbulence at an average Taylor scale Reynolds number of 83 were performed to study joint PDFs of two mixture fractions. The simulations were performed on a triply periodic cubic domain with 256^3 grid points. As shown in the images below, eleven different initial scalar configurations were considered in this study, which were all mixed using identical turbulent velocity fields.

*Available Data*

Three types of data from this study are available for all eleven configurations:

- Raw data: The values of the three velocity components and the two mixture fractions for each configuration at every grid point, stored for 102 temporal snapshots spanning the initial unmixed state to the final fully mixed state. These data are available as binary files (180 GB total), and a Python code can be provided for reading the data.
- Binned PDF data: The above raw data binned into joint and marginal PDFs of the two mixture fractions for each configuration, with 512 bins for each mixture fraction. These data are available as ASCII text files (184 MB total).
- Moment data: Mean, (co-)variance, and skewness of the two mixture fractions for each configuration, stored at every DNS time step. These data are available as ASCII text files (4 MB total).

*Reference*

- B.A. Perry, M.E. Mueller, Joint probability density function models for multiscalar turbulent mixing,
*Combustion and Flame***193**(2018) 344-362

**Sydney Inhomogeneous Inlet Flame Boundary Conditions**

*Overview*

The piloted jet burner with inhomogeneous inlets developed at the University of Sydney is a well characterized burner designed to probe partially premixed, multi-modal combustion. It has been a target configuration for combustion models at recent International Workshop on Measurement and Computation of Turbulent Flames (TNF). The key feature of this burner is the compositionally inhomogeneous mixture at the burner exit, generating by inhomogeneous partial premixing of fuel and air within the burner. To aid in the comparison of simulations from various groups, well-resolved LES calculations of the mixing within the nozzle have been conducted to provide a standard boundary condition for the mixture fraction and velocity profile at the nozzle exit.

*Available Data*

The boundary condition datasets consist of unsteady cross-sections of the three components of the velocity, mixture fraction, and the square of the mixture fraction (to obtain the subfilter mixture fraction variance) at a location one diameter upstream of the burner exit. The data are provided in cylindrical coordinates (both the spatial components and the velocity components), corresponding to the axial (x/u), radial (y/v), and circumferential (z/w) directions. The cross-section has 161 points in the y-direction and 64 points in the z-direction. For each case, data are included for approximately 10,000 time steps spaced by 0.25 us. Datasets are available for the following cases:

- FJ200-5GP-Lr75-57 (fuel/air mixing and air/air mixing)
- FJ200-5GP-Lr75-80 (fuel/air mixing and air/air mixing)
- FJ200-5GP-Lr300-59 (fuel/air mixing)

These data are available as binary files (4 GB each), and a C code can be provided for reading the files.

*References*

- B.A. Perry, M.E. Mueller, Effect of multiscalar subfilter PDF models in LES of turbulent flames with inhomogeneous inlets,
*Proceedings of the Combustion Institute***37**(2019) 2287-2295 - B.A. Perry, M.E. Mueller, A.R. Masri, A two mixture fraction flamelet model for Large Eddy Simulation of turbulent flames with inhomogeneous inlets,
*Proceedings of the Combustion Institute***36**(2017) 1767-1775

**Turbulent Premixed Planar Jet Flames DNS Data**

*Overview*

Two Direct Numerical Simulations of low Mach number spatially-evolving turbulent premixed hydrogen/air planar jet flames at low (case K1) and high (case K2) Karlovitz numbers at the same bulk Reynolds number of 5,000 were performed to better understand and model the influence of combustion heat release on turbulent shear flows. A turbulent central jet is composed of a stoichiometric hydrogen-air mixture diluted with nitrogen at room temperature and atmospheric pressure, and laminar coflows are composed of equilibrium combustion products of the same mixture. The in-flame Karlovitz number is 3.7 for case K1 (left) and 54.0 for case K2 (right) at a streamwise location three central jet heights downstream of the nozzle exit.

*Available Data*

The raw data as binary files and post-processed statistics as text files for velocity and scalars (species mass fractions and temperature) are available. The size of the raw data is 15.7 GB for case K1 and 30.8 GB for case K2 for each instantaneous snapshot, and the size of the post-processed statistics is a few MB in total. The post-processed statistics include mean and (co-)variance of velocity and scalars, which are unconditionally or conditionally averaged with respect to a progress variable, and their budgets at different streamwise and cross-stream locations.

*References*

- J. Lee, M.E. Mueller, Closure modeling for the conditional Reynolds stresses in turbulent premixed combustion,
*Proceedings of the Combustion Institute***38**(2021) 3031-3038 - J. Lee, J.F. MacArt, M.E. Mueller, Heat release effects on the Reynolds stress budgets in turbulent premixed jet flames at low and high Karlovitz numbers,
*Combustion and Flame***216**(2020) 1-8 - J.F. MacArt, T. Grenga, M.E. Mueller, Evolution of flame-conditioned velocity statistics in turbulent premixed jet flames at low and high Karlovitz numbers,
*Proceedings of the Combustion Institute***37**(2019) 2503-2510 - J.F. MacArt, T. Grenga, M.E. Mueller, Effects of combustion heat release on velocity and scalar statistics in turbulent premixed jet flames at low and high Karlovitz numbers,
*Combustion and Flame***191**(2018) 468-485