Deformation of the Vertical Velocity Profile during Deceleration of a Flow with an Adverse Pressure Gradient
O. N. Mel’nikova, H. T. Yang
Abstract
Abstract It has been shown experimentally that an adverse pressure gradient leads to periodic deceleration of the boundary layer of a plane-parallel flow in an open channel. During the deceleration, the action of the reverse pressure gradient and friction force forms an instantaneous vertical velocity profile with a local minimum above the viscous layer between two inflection points. In a thin layer containing the upper inflection point, the plane-parallel flow is unstable, which has been confirmed experimentally: a cylindrical vortex is formed in this layer at a critical value of the reverse pressure gradient when the deceleration cycle terminates.
Topics & Concepts
Inflection pointAdverse pressure gradientPressure gradientMechanicsBoundary layerFlow (mathematics)Plane (geometry)Velocity gradientMaterials scienceDeformation (meteorology)VortexFlow separationPhysicsGeometryMeteorologyMathematicsFluid Dynamics and Turbulent FlowsParticle Dynamics in Fluid FlowsComputational Fluid Dynamics and Aerodynamics