Shear Layer Stability Analysis in Later Boundary Layer Transition and MVG Controlled Flow
نویسندگان
چکیده
A 1-D and 2-D cylindrical flow stability is investigated in this paper. A typical velocity profile in a shear layer with infection point is studied first. The fluid motion is decomposed to two parts: the rotational part and shear part. Linear stability analysis shows the rotational part (like rigid body) is stable but the shear part is unstable. Of course, the shear layer with inflection point is unstable as well. Following this analysis, a velocity profile taken from the later boundary layer transition and another one from flow field generated by the micro vortex generator are taken as the base flow. A general mechanism of vortex ring formation has been observed, that an olive-shaped momentum deficit zone is formed by vortex ejection and the momentum deficit forms a strong shear layer. Finally, vortex rings are formed around the olive-shaped low speed zone which generates a shear layer.
منابع مشابه
Boundary Layers and Heat Transfer on a Rotating Rough Disk
The study of flow and heat transfer over rotating circular disks is of great practical importance in understanding the cooling of rotatory machinery such as turbines, electric motors and design and manufacturing of computer disk drives. This paper presents an analysis of the flow and heat transfer over a heated infinite permeable rough disk. Boundary-layer approximation reduces the elliptic Nav...
متن کاملEntropy generation in hydromagnetic and thermal boundary layer flow due to radial stretching sheet with Newtonian heating
The entropy generation during hydromagnetic boundary layer flow of a viscous incompressible electrically conducting fluid due to radial stretching sheet with Newtonian heating in the presence of a transverse magnetic field and the thermal radiation has been analyzed. The governing equations are then solved numerically by using the fourth order Runge-Kutta method with shooting technique. The eff...
متن کاملInfluence of Different Inlet Flow on the Ring-like Vortex Structure in MVG Controlled Supersonic Ramp Flow
In this paper, we study the influence on the ring-like vortex structure in MVG controlled supersonic ramp flow by different inflow conditions. In front of the MVG, three turbulent inflow profiles with different boundary layer thickness are generated as the inflow. From the shape factors, we can see that these inflows in front of the MVG are fully developed turbulent. It is found that the inflow...
متن کاملInvestigations on controlled transition development in a laminar separation bubble by means of LDA and PIV
When a laminar boundary layer separates because of an adverse streamwise pressure gradient, the flow is subject to increased instability with respect to smallamplitude disturbances. Laminar–turbulent transition occurs under a rapid three-dimensional (3D) development within the separated shear layer. When the following turbulent boundary layer reattaches, a laminar separation bubble is formed. T...
متن کاملNumerical Simulation of Separation Bubble on Elliptic Cylinders Using Three-equation k-? Turbulence Model
Occurrence of laminar separation bubbles on solid walls of an elliptic cylinder has been simulated using a recently developed transitional model for boundary layer flows. Computational method is based on the solution of the Reynolds averaged Navier-Stokes (RANS) equations and the eddy-viscosity concept. Transitional model tries to simulate streamwise fluctuations, induced by freestream turbulen...
متن کامل