Optical Doppler tomography is demonstrated to be a simple, accurate, and noncontact method for measuring the fluid velocity of laminar flow in small-diameter (~0.5-mm) ducts. Studies are described that utilize circular (square) plastic (glass) ducts infused with a moving suspension of polymer microspheres in air and buried in an optically turbid medium. The measurement of Doppler-shifted freque...

Abstract This paper presents the numerical study of thermal performance factor Al 2 O 3 -Cu/water hybrid nanofluid in circular and non-circular ducts (square rectangular). Turbulent regime is studied with Reynolds number ranges from 10000 to 100000. The heat transfer flow behaviour are investigated, considering volume concentration between 0.1 2%. evaluated terms evaluation criteria (PEC). pres...

Experimentation has been carried out to find the influence of a gap provided in ribs on thermohydraulic performance of a square duct roughened with discrete inclined ribs. The two opposite walls of the square duct are roughened with ribs having attack angle (α) of 45 and a gap on its length. The investigation has been performed for relative roughness pitch (p/e) of 10, relative roughness height...

This study is concerned with the numerical analysis, formulation, programming and computation of steady, 3D conservation equations of reacting laminar flow heat and mass transfer in ducts of arbitrary cross-sections. The non-orthogonal boundary-fitted coordinate transformation method is applied to the Cartesian form of overall-continuity, momenta, energy and species-continuity equations, parabo...

We carry out direct numerical simulation (DNS) of flow in a turbulent square duct by focusing on heat transfer effects, considering the case unit Prandtl number. Reynolds numbers up to $Re_\tau \approx 2000$ are considered which much higher than previous studies, and yield clear scale separation between inner- outer-layer dynamics. Close similarity behavior temperature streamwise velocity field...