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We report two chaotic micromixers that exhibit fast mixing at low Reynolds numbers in this paper. Passive mixers usually use the channel geometry to stir the fluids, and many previously reported designs rely on inertial effects which are only available at moderate Re. In this paper, we propose two chaotic micromixers using two-layer crossing channels. Both(More)
A comparative flow study has been conducted on two configurations of the Fontan operations for congenital heart defects in which the right ventricle is by-passed. The study was made on rigid in vitro models of the atriopulmonary and cavopulmonary connections under steady-flow conditions. It involved using pressure and flow measurements to determine the(More)
A two-dimensional particle image tracking velocimetry (PIV) system has been used to map the velocity vector fields and Reynolds stresses in the immediate downstream vicinity of a porcine bioprosthetic heart valve at the aortic root region in vitro under pulsatile flow conditions. Measurements were performed at five different time steps of the systolic phase(More)
Velocity profiles and Reynolds stresses downstream of heart valve prostheses are vital parameters in the study of hemolysis and thrombus formation associated with these valves. These parameters have previously been evaluated using single-point measurement techniques such as laser Doppler anemometry (LDA). The purpose of this study is to map the velocity(More)
Particle Image Velocimetry (PIV), capable of providing full-field measurement of velocities and flow stresses, has become an invaluable tool in studying flow behaviour in prosthetic heart valves. This method was used to evaluate the performances of four prosthetic heart valves; a porcine bioprostheses, a caged ball valve, and two single leaflet tilting disc(More)
An explicit lattice Boltzmann method (LBM) is developed in this paper to simulate flows in an arbitrary geometry. The method is based on the standard LBM, Taylor-series expansion, and the least-squares approach. The final formulation is an algebraic form and essentially has no limitation on the mesh structure and lattice model. Theoretical analysis for the(More)
Considering the fact that the compression work done by the pressure and the viscous heat dissipation can be neglected for the incompressible flow, and its relationship with the gradient term in the evolution equation for the temperature in the thermal energy distribution model, a simplified thermal energy distribution model is proposed. This thermal model(More)
Full-field measurement of instantaneous velocities in the flow field of artificial heart valves is vital as the flow is unsteady and turbulent. Particle image velocimetry (PIV) provides us the ability to do this as compared to other point measurement devices where the velocity is measured at a single point in space over time. In the development of a PIV(More)
The Taylor series expansion-and least squares-based lattice Boltzmann method (TLLBM) was used in this paper to extend the current thermal model to an arbitrary geometry so that it can be used to solve practical thermo-hydrodynamics in the incompressible limit. The new explicit method is based on the standard lattice Boltz-mann method (LBM), Taylor series(More)