What is your assessment of this so far?Swamp Thing said:Is it possible to create (nearly?) laminar flow in a tube with rectangular C.S. , around 1 cm X 5 cm , with air moving at around 100 to 150 m/sec?
Turbulence will likely set in sooner or later, but can the laminar flow be made to last over say 20 cm?
I agree.Swamp Thing said:When I posted, I had got a Reynolds number around 7000. So I was wondering if it would work if we used a sheaf of soda straws or something to laminarize the flow.
But I have since found errors in my calculation -- the RN is actually like 260,000. So it's probably not doable, I'm thinking.
Laminar flow refers to a smooth, orderly movement of fluid, in which layers of the fluid flow parallel to each other without disruption. This is in contrast to turbulent flow, where the fluid undergoes irregular fluctuations and mixing.
Yes, it is possible to create laminar flow in fast-moving air, but it is challenging. Achieving laminar flow in fast-moving air requires careful control of the air's velocity, pressure, and the surface over which it flows. Specially designed equipment and environments, such as wind tunnels with smooth walls and precise airflow controls, are often used to achieve this.
The transition from laminar to turbulent flow is influenced by several factors, including the Reynolds number (a dimensionless quantity that depends on the fluid's velocity, density, viscosity, and characteristic length), surface roughness, and disturbances in the flow. Higher Reynolds numbers and surface roughness typically promote turbulence.
Maintaining laminar flow in fast-moving air can be achieved by minimizing disturbances and surface roughness, and by carefully controlling the flow conditions. Techniques such as using streamlined shapes, smooth surfaces, and gradual changes in the flow direction can help maintain laminar flow. Additionally, flow control devices and boundary layer suction can be employed to stabilize the flow.
Achieving laminar flow in fast-moving air has several practical applications, including reducing drag on aircraft and vehicles, improving the efficiency of ventilation systems, enhancing the performance of wind tunnels, and optimizing the design of aerodynamic surfaces. Laminar flow can lead to significant energy savings and performance improvements in these applications.