 Okay, hello everyone. My name is Zhang. I would like to talk about my research, Entryment and Scholar Mixing Process Near the Turbulent Low Turbulent Interface in Compressible Boundary Layer. So this is the outline of my presentation. Introduction, Computational Methods and Results Turbulent No Turbulent Interface Entryment and Scholar Mixing Process Near the TNT Conclusion This is a picture of the Turbulent Boundary Layer. The Boundary Layer has been discussed for many years, and most research are focused on the near origin, but in the intermittent region where the Turbulent and Low Turbulent Flow coexist is still lack of information. And recent research show there exists a Sun Layer which separates the Turbulent and Low Turbulent Flows in the intermittent region. It's called as Turbulent-Low Turbulent Interface. It also writes like TNTI. So it's easy to know that if those Low Turbulent Flows pass through this TNTI, it's become Turbulent Flow. And related to the Spatial Turbulent Development. So we can say that this interface is important for the exchanges of substance energy and heat transport between Turbulent and Low Turbulent Flow. So this interface has been studied a lot in the free shear flow. For example, in the jet flow and in the mixing layer. But this interface in the Turbulent boundary layer has been hardly discussed. And the compressibility effect is lack of information. For the objective in this presentation, so at first we want to examine the characteristics of this TNTI in the Turbulent boundary layer and show the instrument and the scale mixing process near the TNTI. Okay, so before I talk about my research, I would like to introduce the structure of Turbulent-Low Turbulent Interface. As shown in this figure, this is the TNTI layer. And the outer ED of this layer is called Innotation Boundary. Which is detected by a vorticity isosurface in this study. And this layer contains two layers. Viscose Super Layer, which is dominated by viscosity. And another one is Turbulent Sub Layer. So in my start, in my numerical simulation, the 3D compressible NS equation and the scalar transport equation is solved. And this game for the computation is shown here. This is the initial condition. The wall is moved with a constant velocity, Uw. And the velocity is not in the free shear flow. For tracker, the Turbulent transition, the velocity fluctuation is at the leader of the wall. And for the boundary condition, the purely co-boundary condition is used for the streamwise and spanwise direction. For the normal or normal direction, this is the wall. And this boundary uses the low-effect NSBCB condition with a sponger layer. So in this study, we performed a two-case with a different mass number. 0.8 and 1.6. The computational domain and the grid point is here. The computational domain here is decided by the boundary layer synchronous in the end of the simulation. And the resolution of the computation at the wall is shown in this form. By this, we can ensure that the grid is enough in the near wall. But for study, the Turbulent and low Turbulent interface is also important to ensure that the resolution is enough in this region. So in this study, we limited the resolution around 1.5 column of golf in this study. And the column of golf scale used here is the column of golf scale in the Turbulent core. This is a visualization of the Turbulent boundary layer development. We can see that the boundary layer is developed from the laminar to the Turbulent floor. So the mean stream-wise velocity and stream-wise velocity are shown here. For the mean stream-wise velocity, it's agreeable with the theoretical laws. And the stream-wise velocity is compared with experimental data and the data is in other direct-numeric stream-wise. So this is the in-lotational boundary layer, which is the out-ED of the Turbulent-low Turbulent interface layer. It's validized by a velocity iso-surface in this figure. And the color in this interface is the dilatation. The minus and plus value of the dilatation refers to the fluid expansion and compression here. So from the figure, we say that the fluid compression and the expansion are both exist on the interface. And the structures with different length scales also exist on the interface. And here I showed some results. And this result is... I have performed DNIs before now. And in this study, we didn't consider the resolution of the Turbulent-low Turbulent interface. Just consider the near-all region. So you can see the results in this study and the surface is not very smooth. But after we consider about this, you can see it's become very smooth. And this result is very similar with the result in the jet flow and the mixing layer. So for study, the Turbulent-low Turbulent flow statistics separate me. The local coordinate system YI is built here. The orange point is on the in-lotational boundary. And the normal direction is calculated by the install of a gradient. So by this local coordinate, the statistics can be calculated for the Turbulent-low Turbulent side separating. For deciding this TNTI layer synthesis, we calculate the Voticity fluctuation RMS on the local coordinate system YI. This is the result. This right dot line is the corresponding divert. So we can see that in this region, the Voticity fluctuation increased and become flat in the Turbulent score. So this region is the Turbulent-low Turbulent interface. And we decided the checklist here is around the 15 column of golf scale. The most study to determine the synthesis of the TNTI, they use the Voticity to determine that. But we choose the Voticity fluctuation here because the Voticity is a significant effect by the war. So this way can avoid the effect of the war. And we also calculate the install of a transport budget. The Viscosity fluctuation and the production term is showing this figure. And this is the Turbulent-low Turbulent layer. And we can see that in this region, the Viscosity fluctuation is larger than the production term. So the install phase increased by the Viscosity fluctuation here. In this region, the install phase increased by the production term. This region is the so-called Viscosity super-layer and this is Turbulent sub-layer. The think list about them is shown here. The Viscosity super-layers I want to go at Turbulent sub-layer is about 10-8. We'll talk about the instruments here. So for the instruments, normally there are two ways to take the flow, from the low Turbulent region to the Turbulent region. The first one is called an evening, in which the low Turbulents acquire Viscosity by the small scales near the Turbulent-low Turbulent interface. The other one is the engulfment. In the engulfment, the low Turbulent flow is directly drawn into the Turbulent region before acquiring the Viscosity, which is used by the large-scale EDs. And we will talk about the evening here, which is also called local entrapment. This evening is the propagation of the inlotation boundary, which is our Viscosity iso-surface, and the propagation velocity can calculate by this equation. This is the PDF result of the propagation velocity. We can see that this velocity is almost plus in this result. That means the inlotation boundary is propagated towards the low Turbulent region, and hardly propagates towards the Turbulent region. So we also calculate the budget of the propagation velocity here. And you can see this is a PDF result. This result is the most contributing term, which is Viscosity term. And the subdivision of the Viscosity term is calculated in those figures. The red line is the Viscosity fusion, and the black line is the Viscosity dissipation. So from this result, you can see that the propagation velocity can mainly be supported by the Viscosity fusion term. So in here, for study the mass transportation between the Turbulent and low Turbulent interface, we consider another coded system, like this, which is the Boole with inlotation boundary. So in this system, the continuity equation calculates like this. Here the dirty UI is the fluid difference between the velocity difference between the fluid velocity and the movement velocity of the inlotation boundary. And the mass flux in this equation can be divided into two components, the normal component and the tangential component. Be careful that this FN normal component, if the FN is smaller than zero, it means the mass is transported towards the Turbulent region. So in here, the joint PDF of the normal component mass flux and tangential component mass flux is showed here. In the Viscosity super layer, the tangential component is very small. And the normal component is almost smallest. That means the fluid in the Viscosity super layer is transported towards the Turbulent region. So from this result, we can say that the fluid in the Viscosity super layer comes from the low Turbulent region. And in this Turbulent sub-layer, the tangential component becomes very large. And both the plus value and the minus value exist for the normal component. The flux, the mass transportation becomes complicated in this sub-layer. So in this layer, it's easy to say that fluid comes from both the low Turbulent and the Turbulent regions. Okay, so the Scala is also calculated in this research. This is the Min Scala, and this is the Scala dissipation rate. You see that Min Scala is rapid with the Turbulent-low Turbulent interface layer. And the peak of the Scala dissipation rate exists here, which is near the interface between the Viscosity super layer and the Turbulent sub-layers. That means that the strong mixing process is at this location. And if we look at here, in the low Turbulent region and the Viscosity super layer, the volume of the Scala is very small. And the Scala is much larger in the Turbulent core region and Turbulent sub-layer. This invites that the fluid in the Viscosity super layer come from the Turbulent region. And it meets the fluid in the Viscosity super layer come from the low Turbulent region. And it meets the fluid which is coming from the Turbulent region in this location. So this shows the mixing process happen here. So this is the conclusion of my research. So at first, we performed the direct inverse simulation. The high-resolution Turbulent boundary layer DNA code is developed and validated. And we analyzed the statistical characteristics from the result. We can say that it's very important to consider the resolution as the Turbulent low Turbulent interface compared to the classical Turbulent DNA. The Turbulent layer is about 5-8. Viscosity super layer is about 10-8. For the instrument and the Scala mixing process, the local instrument is mainly contributed by the Viscosity fusion. And in the Viscosity super layer, the fluids come from the low Turbulent region. And in the Turbulent sub-layer, the fluids come from both the Turbulent and low Turbulent regions. For the Scala mixing process, the strong mixing process occurs near the interface of Viscosity super layer and Turbulent sub-layer. Okay, that's all.