Effect of compartmentalization design of the internal coolant cavities in chord-wise on flow and heat transfer characteristics of double-wall rotor blades

Double-wall cooling is a key technology for enhancing the temperature resistance capacity of advanced turbine blades. However, under high-load operating conditions, the cavity design of double-wall blades directly affects their cooling performance. A double-walled turbine rotor blade with chordwise-partitioned internal cooling cavities is proposed in this study. The overall cooling effectiveness (OCE) of the prototype blade (PT) and the optimized blade (OPT) are obtained under four representative operating points using conjugate heat transfer method. The results indicate that the chord-wise partitioned cavities of OPT significantly enhances the uniform distribution of coolant, allowing its OCE to reach 0.78 under design point conditions. The spanwise-averaged OCE of OPT features a bimodal distribution along the streamwise, more evenly distributed than PT’s unimodal pattern. The difference in the arc-averaged OCE between the two blades on the PS is greater than that on the SS. OPT exhibits consistently higher section-averaged cooling effectiveness than PT, with a more uniform distribution of effectiveness across the section. The increase ratio of OCE on the PS is more sensitive to condition changes than that on the SS, and it increases with the operating pressure rise. Compared to PT, the OPT outperforms in cooling and aerodynamics under OP₁, OP₂ and OP₃: OCE increases by 2.27 %, 4.99 %, and 4.05 %, while total pressure loss coefficient ( C_pt ) decreases by 0.04 %, 3.57 %, and 3.36 %.