Two‐scale conjugate heat transfer solution for micro‐structured surface

Abstract The primary challenges for simulating a turbulent flow over micro‐structured surface arise from the two hugely disparate spatial length scales. For fluid–solid coupled conjugate heat transfer (CHT), there is also time‐scale disparity. present work addresses scale disparities based on two‐scale framework. disparity, dual meshing employed to couple global coarse‐mesh domain with local fine‐mesh blocks around micro‐structures through source terms generated and propagated domain. convergence robustness of driven solution enhanced by balanced eddy‐viscosity damping. In this work, method previously developed only fluid‐domain extended solid so that thermal conduction micro‐elements can now be resolved accurately efficiently. timescale disparity dealt frequency approach. time‐averaged (zeroth harmonic) effectively obtained in same way as steady CHT. And remarkably, wall temperature unsteadiness simply fluid harmonics harmonic transfer‐function at minimal computational cost. CHT capability validated an experimental internal cooling channel multiple rib‐elements. test configuration 100 micro‐structures, domain‐only, domain‐only solutions are analyzed respectively examine demonstrate validity framework implementation methods. Some results serve illustrate underlying working methodology.