What is laminar flow over a flat plate?
The laminar boundary layer over a smooth flat plate is known to become unstable to small disturbances at a sufficiently high Reynolds number, typically in the range of 1.5 × 105 < Rex < 1.5 × 106. In this range the laminar flow develops periodic and then fully random turbulent fluctuations in the flow.
What is the critical Reynolds number for flow over a flat plate?
Rex ~ 500000
For flow over a flat plate, the generally accepted value of the critical Reynolds number is Rex ~ 500000. For flow in a pipe of diameter D, experimental observations show that for “fully developed” flow, laminar flow occurs when ReD < 2300 and turbulent flow occurs when ReD > 3500.
What are the reasons for flow to become turbulent while flowing over a smooth flat plate?
As the fluid flows past the long flat plate, the flow will become turbulent at a critical distance xcr downstream from the leading edge. For flow past a flat plate, the transition from laminar to turbulent begins when the critical Reynolds number (Rexcr) reaches 5×105.
What is Epsilon in Colebrook equation?
version 1.1 (1.8 KB) by ILDEBERTO DE LOS SANTOS RUIZ. Computes the friction factor in pipes for given values of the Reynolds number (Re) and the relative roughness coefficient (epsilon).
What are the boundary conditions for the Blasius equation?
It is referred to as the Blasius equation after the name of the author that discovered it. The boundary conditions to satisfy are f = 0, for η= 0,, (19.26) df dη = 0, for η= 0,, (19.27) df dη → 1, for η→ ∞. (19.28) The last condition (19.28) is (19.9) worked out through (19.10) and (19.19).
Are velocity profiles similar to Blasius’s solution?
The analytical similarity solution of Blasius is presented. Then approximation methods are carried out and a numerical approach is investigated. These calculations showed that the numerical approach yields velocity profiles that are very similar to Blasius’ solution. Third, velocity measurements have been carried.
How do we measure the velocity of a flat plate?
Third, velocity measurements have been carried. Hot Wire Anemometry is used to measure the velocity profile inside the boundary layer along the flat plate. A flap at the trailing edge of the flat plate is used to ensure that leading edge of the plate is at zero degree angle of attack.