Cooled MarkII blade surface pressure and temperature distribution by a conjugate heat transfer analysis using Reynolds stress baseline turbulence model

A conjugate heat transfer analysis obtained the pressure and temperature distribution on the MarkII blade surface. Hot gas is passed over the blade surface and cooled by ten cooling circular channels embedded along its span. The analysis domain was the hot gas flow extended to the blade structure. The cooling channels are out of the numerical analysis and considered thermal convective boundary conditions. 3-D finite volume FLUENT numerical software coupled with a Mechanical ANSYS workbench was used to reveal the physical aspects. Among the turbulence models, the Reynolds Baseline Stress Model (RSM-BSL model) showed the best agreement for temperature distribution compared to the experimental results with a maximum of 4.27% root mean square error. The pressure coefficient on the blade pressure surface with most turbulence models strongly agreed with the experimental results. Only the three-equation model of k-kl-Omega on the blade suction surface exhibited some discrepancies when passing through the strong shock region. At the same time, the results of other models were consistent with the experimental tests. The blade solid temperature decreases to 392 K; while, the hot gas temperature is 788 K. This low-temperature region of the blade solid is experienced between the three first cooling channels near the leading edge. Some temperature fluctuations on the blade surface were observed due to the separate circular cooling channel configuration. This can be prohibited by designing wide duct-shaped cooling channels with rectangular cross sections. A test MarkII blade and a 3D-printing coolant housing are separately manufactured to check the cooling mass flow rate distribution through the cooling channels. The housing with a 40 mm height showed the best mass flow rates compared to experiments.