Fig. 1. Topology of LFM: (a) a tetrahedral unit cell; (b) a single layered LFM sandwiched between face sheets, showing structural anisotropy.

Fig. 2. Photograph of test rig used to obtain detailed fluid-flow and heat transfer patterns.

Fig. 3. Photograph of the pressure tapping ring installed.

Fig. 4. Transverse plane used for PIV velocity measurements.

Fig. 5. Photograph of borescope setup to monitor the color change of the liquid crystal coated on outer surface of cylinder tube; it captures images from within the tube.

Fig. 6. Simulated local flow patterns over the LFM at Re_dp=2.0×10⁴ showing formation of vortex structures.

Fig. 7. Comparisons of the flow velocity fields at a plane obtained from the PIV measurements and steady CFD calculation at Re_dp=2.0×10⁴: (a) y-velocity component; (b) z-velocity component.

Fig. 8. An identified vortex structure (arch-shaped vortex) behind vertex of type 2: (a) calculated flow pattern at Re_dp=2.0×10⁴ where half of the arch-shaped vortex is shown; (b) sketch of formation of the arch-shaped vortex.

Fig. 9. An identified vortex structure (arch-shaped vortex) behind vertex of type 1: (a) calculated flow pattern at Re_dp=2.0×10⁴ where half of the arch-shaped vortex is shown; (b) sketch of formation of the arch-shaped vortex.

Fig. 10. Visualised endwall flow patterns for Orientation A obtained from: (a) oil flow visualization; (b) the TLC.

Fig. 11. Visualised endwall flow patterns for Orientation A obtained from: (a) TLC; (b) steady CFD calculation.

Fig. 12. Visualised endwall flow patterns for Orientation B obtained from: (a) oil flow visualization; (b) TLC.

Fig. 13. Configuration of a unit cell in Orientation A, showing two different types of struts.

Fig. 14. Flow on strut surface of type I, (a) surface flow pattern obtained using oil flow visualization technique at Re_dp=1.0×10⁵; (b) static pressure distribution on strut of type I at Re_dp=2.0×10⁴.

Fig. 15. Simulated flow feature at z/H  0.3 showing formation of a vortical flow on strut of type I at Re_dp=2.0×10⁴.

Fig. 16. Variation of C_p along circumference of strut of type I at Re_dp=2.0×10⁴.

Fig. 17. Static pressure distribution on strut of type II at Re_dp=2.0×10⁴: (a) pressure distribution on each strut from the CFD simulation; (b) measured C_p contour.

Fig. 18. Variation of static pressure along circumference of strut of type II at Re_dp=2.0×10⁴.

Fig. 19. Comparisons of the pressure loss coefficients obtained from the measurements and the CFD simulation.

Fig. 20. Comparisons of circumferential variation of C_p obtained from the experiments and the CFD calculation for midspan of the struts at Re_dp=2.0×10⁴.

Fig. 21. Comparison of average Nusselt numbers obtained from measurements and CFD simulation for Orientation A.

Fig. 22. Comparisons of the surface Nusselt number distributions of lower endwall plate in Orientation A at Re_dp=2.0×10⁴ contained from: (a) TLC; (b) CFD simulation.

Fig. 23. Comparisons of local surface Nusselt numbers measured using the TLC with those from the CFD calculation at Re_dp=2.0×10⁴ for selected longitudinal location on the lower endwall: (a) at x/d_p = 0.5; (b) at x/d_p = 1.0.

Fig. 24. Comparison of circumferential variation of the Nusselt number on the strut of type I obtained from the TLC at Re_dp=2.0×10⁴: (a) at z′/l = 0.3 and (b) at z′/l = 0.5.

Fig. 25. Estimation of the contribution of the endwall and strut surfaces to the overall heat transfer for ε = 0.938 at Re_dp=2.0×10⁴: (a) surface area density fraction; (b) effect of the flow separation on the heat transfer from the strut surface; (c) contribution of the vortex structures.

Fig. 26. Contribution of significant flow features to the overall heat transfer at Re_dp=2.0×10⁴.

Fig. 27. Performance charts of different heat dissipation media: (a) friction factor; (b) heat transfer; (c) efficiency index Nu_H/f^1/3.

Specifications of the wind-tunnels employed for both pressure drop and heat transfer measurements where L_parallel is a length of the parallel section and H, W, L and are the channel height, width, and length, respectively

Estimated contribution of the local flow features

All of the data were measured from TLC at Re_dp=2.0×10⁴ for both the endwall and the struts.