A process has been developed by which mean velocity and concentration measurements can be used to determine optimal turbulent diffusivity values for an angled jet in cross-flow configuration. This configuration has applications in film cooling for gas turbine blades. The measurements, obtained by magnetic resonance imaging techniques, provide 3D time-averaged velocity and concentration fields. The mean velocity field is fed into a Reynolds-Averaged Advection Diffusion solver, which uses a turbulent diffusivity model to solve for the mean coolant concentration distribution. This distribution can be compared to the experimentally-obtained concentration field by means of an error metric that quantifies the difference between the computational and experimental concentration fields. By minimizing this error, an optimal value of the turbulent diffusivity can be determined. This optimized distribution is then compared to a RANS simulation to evaluate the relative contribution to error of the turbulent momentum flux model versus the turbulent scalar flux model.
|Original language||English (US)|
|Number of pages||10|
|Journal||International Journal of Heat and Fluid Flow|
|State||Published - Dec 2013|
Bibliographical noteFunding Information:
J. Ling was supported by an NSF Graduate Research Fellowship. The authors acknowledge the following award for providing computing resources that have contributed to the research results reported within this paper: MRI-R2: Acquisition of a Hybrid CPU/GPU and Visualization Cluster for Multidisciplinary Studies in Transport Physics with Uncertainty Quantification, Award Number 0960306. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The authors also gratefully acknowledge the guidance and help of G. Iaccarino and C. Gorle.
- Film cooling
- Turbulent Prandtl number
- Turbulent Schmidt number
- Turbulent diffusivity