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A bypass transition is a laminar–turbulent transition in a fluid flow over a surface. It occurs when a laminar boundary layer transitions to a turbulent one through some secondary instability mode, bypassing some of the pre-transitional events that typically occur in a natural laminar–turbulent transition.
Transition modeling is the use of a model to predict the change from laminar and turbulent flows in fluids and their respective effects on the overall solution. The complexity and lack of understanding of the underlining physics of the problems makes simulating the interaction between laminar and turbulent flow to be difficult and very case specific.
Reynolds’ 1883 experiment on fluid dynamics in pipes Reynolds’ 1883 observations of the nature of the flow in his experiments. In 1883 Osborne Reynolds demonstrated the transition to turbulent flow in a classic experiment in which he examined the behaviour of water flow under different flow rates using a small jet of dyed water introduced into the centre of flow in a larger pipe.
For flow in a pipe of diameter D, experimental observations show that for "fully developed" flow, [n 2] laminar flow occurs when Re D < 2300 and turbulent flow occurs when Re D > 2900. [ 13 ] [ 14 ] At the lower end of this range, a continuous turbulent-flow will form, but only at a very long distance from the inlet of the pipe.
Gamma-Re (γ-Re) transition model is a two equation model used in Computational Fluid Dynamics (CFD) to modify turbulent transport equations to simulate laminar, laminar-to-turbulent and turbulence states in a fluid flow. The Gamma-Re model does not intend to model the physics of the problem but attempts to fit a wide range of experiments and ...
In engineering, the Moody chart or Moody diagram (also Stanton diagram) is a graph in non-dimensional form that relates the Darcy–Weisbach friction factor f D, Reynolds number Re, and surface roughness for fully developed flow in a circular pipe. It can be used to predict pressure drop or flow rate down such a pipe.
In fluid dynamics, a Tollmien–Schlichting wave (often abbreviated T-S wave) is a streamwise unstable wave which arises in a bounded shear flow (such as boundary layer and channel flow). It is one of the more common methods by which a laminar bounded shear flow transitions to turbulence. The waves are initiated when some disturbance (sound ...
In the field of fluid dynamics the point at which the boundary layer changes from laminar to turbulent is called the transition point.Where and how this transition occurs depends on the Reynolds number, the pressure gradient, pressure fluctuations due to sound, surface vibration, the initial turbulence level of the flow, boundary layer suction, surface heat flows, and surface roughness.