A square splittered and unsplittered rod is placed in a turbulent boundary layer developed over a flat plate. The effect of the resulting disturbances on the local heat transfer coefficient is then studied. In both cases the square rod modifies the flow structure inside the boundary layer. As a result, a stagnation point, a jet and wake area are generated around the square rod, each making a co...

The results from direct numerical simulations of a spatially evolving super sonic at plate turbulent boundary layer ow with free stream Mach number of are presented The simulated ow eld extends from a transition region initiated by wall suction and blowing near the in ow boundary into the fully turbulent regime Distributions of mean and turbulent ow quantities are ob tained and an analysis of t...

Simulations of turbulent flows are challenging and require tight and varying mesh spacings near the walls that depend on the turbulence models used. Semi-structured meshes are often used in the turbulent wall boundary layers due to their ability to be strongly graded and anisotropic. To reduce the discretization errors in the solution, an adaptive approach becomes essential due to the lack of g...

By considering the entrainment properties of the turbulent boundary layer, a new and simple form of auxiliary equation has been derived for the calculation of the form parameter H. Comparison with experimental results shows very fair agreement and it should be possible to apply the method in circumstances where normal forms of the auxiliary equation would fail. Further experiment or analysis of...

This paper reviews turbulent boundary-layer control strategies for skin-friction reduction of aerodynamic bodies. The focus is placed on the drag-reduction mechanisms by two flow control techniques-spanwise oscillation and spanwise travelling wave, which were demonstrated to give up to 45 per cent skin-friction reductions. We show that these techniques can be implemented by dielectric-barrier d...

Proper orthogonal decomposition (POD) is applied to the direct numerical simulation (DNS) of a turbulent boundary layer performed by Wu & Moin (2010), and the resulting POD modes of various scales are examined. The modes include structures resembling those observed in instantaneous flow fields, such as large-scale motions of streamwise velocity with ramp-like wall-normal growth. Other modes cor...

Over the past decade significant strides have been made in the development of pulse burst laser systems capable of producing high energy laser pulses at repetition rates in excess of 1 MHz. These unique laser systems are currently being used in experiments across a variety of fields ranging from traditional fluid dynamics to combustion to plasma physics. Described here is the use of one such sy...

T. Tsuji Y. Nagano Department of Mechanical Engineering Nagoya Institute of Technology, Nagoya, Japan l lA turbulent natural convection boundary layer along a vertical flat plate in air is investigated with hot-wire techniques. Profile measurements of mean velocity, mean temperature, and turbulent quantities, which are obtained well into the wall region, clarify some characteristics peculiar to...

A turbulent boundary layer subjected to free-stream turbulence is investigated in order to ascertain the scale interactions that dominate the near-wall region. The results are discussed in relation to a canonical high Reynolds number turbulent boundary layer because previous studies have reported considerable similarities between these two flows. Measurements were acquired simultaneously from f...