The newly released FLUENT 4.5 includes enhanced capability for modeling of turbulent and transitional flows. Dubbed the Integrated Turbulence Physics Package (ITPP), this set of optional enhancements provides expanded capability based on renormalization group (RNG) methods for the solution of complex physio-chemical effects at high Reynolds numbers.

Modeling Transition

In the plots below, the ITPP package is applied to the problem of heat transfer in the high pressure turbine nozzle guide vane studied experimentally in the short duration Isentropic Light Piston Compression Tube facility, CT-2, at the von Karman Institute (VKI). This guide vane was designed at VKI in order to provide a database for verification of numerical simulations.

Distribution of heat transfer coefficient along the blade surface (left - suction side; right - pressure side)

Typical heat transfer results for the test case MUR132 are shown here along with the experimental data. For this test case, the freestream inlet parameters include total temperature of 408.5 K, total pressure of 1.757 bar, and density of 1.486 kg/m^3. The inlet velocity and turbulence intensity levels are 52.6 m/s and 0.8%, respectively.

Improved Heat Transfer Predictions

The FLUENT results shown here include the predicted spatial distribution of eddy viscosity. Notice that the eddy viscosity (and, therefore, the turbulence controlled heat transfer coefficient) is an order of magnitude smaller in the ITPP simulation compared to the results for standard k-e modeling, because of pronounced relaminarization of the cascade flow.

The ITPP models yield an accurate quantitative prediction of blade heat transfer over most of the airfoil surface (see figure).

Prediction of eddy viscosity is more accurate with the ITPP package. Transport is overpredicted in the standard k-e model (above), while the RNG-based prediction (below) yields lower heat transfer coefficients observed experimentally.

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