The effect of inlet conditions on the mixing of a passive scalar was investigated in a planar shear layer with inlet boundary layers that were laminar, tripped and naturally turbulent–transitional. Planar laser-induced fluorescence measurements of acetone were used to directly evaluate the shear layer structure, and were processed to determine probability density functions ~PDFs! of the mixture...

A wind-tunnel model was developed to study the two-dimensional turbulent boundary layer in adverse and favourable pressure gradients with out the effects of streamwise surface curvature. Experiments were performed at Mach 4 with an adiabatic wall, and mean flow measurements within the boundary layer were obtained. The data, when viewed in the velocity transformation suggested by Van Driest, sho...

We define turbulent-turbulent spot as a local concentration of vortices with high level of swirling strength originating from hairpin packet in a turbulent boundary layer. We also define bypass transition in the narrow sense as the breakdown of the Blasius boundary layer beneath freestream homogeneous isotropic turbulence with an initial amplitude of 1 to 4 percent. We present evidence for the ...

The interaction between circular synthetic jets and flat-plate laminar/turbulent boundary layers is investigated using CFD simulations in this study. For turbulent boundary layer simulations, large eddy simulation (LES) is applied so as to obtain more accurate flow details. The simulation results are validated using both existing experimental data and numerical results obtained from other resea...

This paper investigates the characteristics of wall pressure fluctuations in naturally developing boundary layer flows on axisymmetric bodies experimentally. The axisymmetric body has a modified ellipsoidal blunt nose. Flush-mounted microphones are used to measure the wall pressure fluctuations in the boundary layer flow over the body. The measurements are performed in a low noise wind tunnel. ...

A novel neuro-based method is introduced to solve the laminar boundary layer and the turbulent free jet equations. The proposed method is based on cellular neural networks, CNNs, which are recently applied widely to solve partial differential equations. The effectiveness of the method is illustrated through some examples.

A novel neuro-based method is introduced to solve the laminar boundary layer and the turbulent free jet equations. The proposed method is based on cellular neural networks, CNNs, which are recently applied widely to solve partial differential equations. The effectiveness of the method is illustrated through some examples.

The objective has been to study turbulent boundary layers under adverse pressure gradients (APG) through direct numerical simulation (DNS). The numerical code is based on a pseudo-spectral technique which is suitable for the simple geometry (flat plate) considered here. A large effort has been put into the optimization of the numerical code on various super computers. Five large simulations hav...

Simulation of wall-bounded turbulent flows poses significant challenges and requires tightly controlled mesh spacing and structure near the walls. Semi-structured or hybrid meshes are often used for turbulent boundary layer flows. These meshes not only account for complex geometry but also maintain highly anisotropic, graded and layered elements near the walls. However, for engineering flow pro...

this study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully eulerian two-fluid model. the closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. gas phaseturbulence is modeled by one-equation model and solid phase turbulence by mlh theory. resultsof one-way and...