Approximate the skin friction drag on a 1m long by 60 cm diameter cylinder, located axially in a wind tunnel, when the air speed is 4.5 m/s. the pressure is atmospheric and the temperature is 50°c.

The drag force is

Explanation:

Given that,

Diameter = 60 cm

Length = 1 m

Air speed = 4.5 m/s

Temperature = 50°C

We need to calculate the Reynolds number

Using formula of Reynolds number

Put the value into the formula

We need to calculate the drag coefficient

Using formula of drag coefficient

Put the value into the formula

We need to calculate the drag force

Using formula of drag force

Put the value into the formula

Hence, The drag force is

this could be newton#'s law of cooling. the cooling curve is exponential