Convective heat transfer in plane channels with in‐line mounted rectangular bars

Flow structure and convective heat transfer in a plane channel with in‐line mounted rectangular bars have been investigated for different bar sizes in the Reynolds number range corresponding to steady laminar flow to unsteady transitional flow. Numerical results are reported for the thermal entrance region with six in‐line mounted bars and for the case with spatially periodic mounted bars. Data for heat transfer and pressure drop are presented for 100≤Re≤1,000 and bar heights 0.24≤d/H≤0.48. The unsteady Navier‐Stokes equations and the energy equation have been solved by a finite‐volume code with staggered grids combined with SIMPLEC pressure correction. Flow and heat transfer characteristics in the different rows are strongly dependent on Re and d/H. The flow structure and temperature field around the sixth row are compared qualitatively well with those calculated with periodic boundary conditions, however, the comparison of mean Nusselt number and friction factor shows differences for high Reynolds numbers.