Aerofoil Reynolds number, meaning of a statement in my homework

[Jeviah]

Homework Statement

hello, i have been given a piece of homework which is determining the characteristics on an aerofoils boundary layer. In the brief the following statement is made with no context “Aerofoil is flying in chord Reynolds number 0.2x10^6” am i correct in saying that is the point at which the boundary layer transitions from laminar to turbulant or would i use this reynolds number to determine the free flow velocity (Um)?

Homework Equations

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The Attempt at a Solution

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[Chestermiller]

Homework Statement

hello, i have been given a piece of homework which is determining the characteristics on an aerofoils boundary layer. In the brief the following statement is made with no context “Aerofoil is flying in chord Reynolds number 0.2x10^6” am i correct in saying that is the point at which the boundary layer transitions from laminar to turbulant or would i use this reynolds number to determine the free flow velocity (Um)?

Homework Equations

N/A

The Attempt at a Solution

N/A

What is the full statement of the problem?

 

[Jeviah]

okay so I've copy and pasted all the info I am given from the brief below and bolded the statement I am unsure about.Based on the current trend of aircraft development, environmental factors such as noise and emission limits will play a more vital role in future transport aircraft design, driving the need for greener more efficient aircraft. Of the primary objectives of the Clean Sky initiative is achieving a total reduction in aircraft drag of 10% by reducing the wing drag by 25%. Another goal is the reduction of fuel burnt by 20%.
Both the reduction in drag and fuel savings are intertwined since through innovative flow control mechanisms. Flow control is the manipulation of flow characteristics to yield desirable effects. The stall condition is an undesirable phenomenon where controlling it will improve the aircraft performance by enabling it to take off and land at higher incidences and lower speeds. Controlling the stall angle can be achieved through delaying the leading edge separation on the aerofoil, which is usually associated with achieving higher lift magnitudes and lower drag. There are several mechanisms in the field of passive and active flow control to prevent leading edge separation.In this study, a NACA 0015 aerofoil constructed from perspex with a chord length, c, of 0.24 m and span of 0.40 m is considered.

The characteristics of this aerofoil are well documented in the literature and it exhibits well-behaved leading edge separation at high angles of attack. Aerofoil is flying in chord Reynolds number of 0.2x106.

the boundary layer analysis on top surface of the aerofoil in zero AoA through calculations and simulation. You may suppose the boundary layer on a flat plate.

 

[David Lewis]

Aerofoil is flying in chord Reynolds number 0.2x10^6. Am I correct in saying that is the point at which the boundary layer transitions from laminar to turbulent, or would I use this Reynolds number to determine the free flow velocity (Um)?

The chord Reynolds number means the wing chord is the characteristic length in the Reynolds number formula.