Flow boiling in miniand microchannels offer very high heat transfer capabilities and find applications in many emerging technologies, such as electronics cooling and fuel cells. The low flow rate employed in such geometries, coupled with the small flow channels, often results in a laminar flow with all flow as liquid. Since the single-phase flow with all liquid is in the laminar range, the flow...

The present work predicts the formation of laminar separation bubbles at low Reynolds numbers and the related transition to turbulence by means of Implicit Large Eddy Simulations with a high-order Discontinuous Galerkin method. The flow around an SD7003 infinite wing at an angle of attack of 4◦ is considered at Reynolds numbers of 10 000, 22 000, and 60 000 in order to gain insight into the cha...

During the past several years we have performed a considerable amount of investigations of basic instability mechanisms in various laminar separation bubbles. Because of the high sensitivity of the flow with respect to intrusive measurement techniques and the difficulties of computing the flow field via boundary-layer equations or RANS our research relies primarily on direct numerical simulatio...

When fluid flows through a channel, pipe, or duct, there are two basic forms of motion: smooth laminar motion and complex turbulent motion. The discontinuous transition between these states is a fundamental problem that has been studied for more than 100 yr. What has received far less attention is the large-scale nature of the turbulent flows near transition once they are established. We have c...

An axisymmetric magnetic field is applied to a spherical, turbulent flow of liquid sodium. An induced magnetic dipole moment is measured which cannot be generated by the interaction of the axisymmetric mean flow with the applied field, indicating the presence of a turbulent electromotive force. It is shown that the induced dipole moment should vanish for any axisymmetric laminar flow. Also obse...

Biofilms were grown from wild-type (WT) Pseudomonas aeruginosa PAO1 and the cell signaling lasI mutant PAO1-JP1 under laminar and turbulent flows to investigate the relative contributions of hydrodynamics and cell signaling for biofilm formation. Various biofilm morphological parameters were quantified using Image Structure Analyzer software. Multivariate analysis demonstrated that both cell si...

Incompressible Navier-Stokes equations are reviewed in this work. Three-dimensional Navier-Stokes equations are solved analytically. The Mathematical derivation shows that the solutions for the zero and constant pressure gradients are similar. Descriptions of the proposed formulation and validation against two laminar experiments and three different turbulent flow cases are reported in this pap...

We consider flow-through systems in which the characteristic length is limited such that turbulent flow is not reached even at high fluid velocities, i.e., the flow remains laminar. In these flow regimes, inducing circulation or vortices in the flow enhances mixing and heat transfer [1]. These can be created by placing obstacles in the flow path, for example. Figure 1. Geometry of the simulatio...

An unsteady flamelet model, which will be called the Lagrangian Flamelet Model, has been applied to a steady, turbulent CH4/H2/N2–air diffusion flame. The results have been shown to be in reasonable agreement with experimental data for axial velocity, mixture fraction, species mass fractions, and temperature. The application of three different chemical mechanisms leads to the promising conclusi...