Effects of the novel rib layouts on the tip leakage flow pattern and heat transfer performance of turbine blade
The steady simulation with flow field and heat transfer performance for different rib layouts is investigated. By referring the GE E3 turbine blade tip (Case 1) profile as a prototype model, four kinds of rib layouts of full rib structure (Case 2) half rib structure connected with suction side (Case 3) half rib structure connected with pressure side (Case 4) and half rib structure in the rear squealer cavity (Case 5) was designed. The availability of k o turbulence model was validated through comparison of heat transfer coefficient distribution with the experimental data. The area averaged heat transfer coefficients of Case 5 decreases up to 11.3% 3.1% 11.3% and 2.8% in comparison to Cases 1, 2, 3, and 4. The total pressure coefficient of Case 5 reduces by 1.4% 2.7% and 4.0% compared to Cases 1, 2, and 3. The results reveal that, among the five novel rib layout cases, Case 5 obtains the optimal comprehensive performance under the performance of considering tip heat transfer and cascade loss. Further investigation on the influence of Cases 1 and 5 at different rotational speeds on the flow field and heat transfer characteristics of the tip clearance is also illustrated and discussed.