Question

Light no. 10 oil is heated from 95°F to 105°F in a 0.6 in inside diameter tube. The average velocity of the oil is 2.0 ft/sec. The viscosity of the oil at 100°F is 45 centistokes (cS). What is the Reynolds number inside the tube?

Answer 1

Re=203.2

Step-by-step explanation:

Given that

d= 0.6 in

1 in = 0.0254 m

d= 0.01524 m

u= 2 ft/s

1 ft/s = 0.30 m/s

u= 0.60 m/s

kinetic viscosity ν = 45 Centistokes

1 Centistokes = 10⁻⁶ m²/s

ν = 45 x 10⁻⁶ m²/s

We know that Reynolds number given as

`Re=(ud)/(\\u )`

Now by putting the values

`Re=(ud)/(\\u )`

`Re=(0.6* 0.01524)/(45* 10^(-6))`

Re=203.2

This is the Reynolds number inside tube.

Answer 2

Re = 2.0645

Step-by-step explanation:

considering pipe with oil flow from 95 degree F to 105 degree F

Average velocity is 2.0 ft./sec

viscosity of oil at 00 degree F is 45 centistoke

`\\u = 45 centi stoke`

`\\u = 45* 10^(-4) m^2/s`

d = 0.6 inch = 0.1524 m

v = 2 ft/sec = 0.609 m/s

Reynold number
`= (inertia\ force)/(viscous\ force)`

`= (\rho vd)/(\mu)`

`= (v d)/(\\u)`

`= ( 0.9096 * 0.1524)/(45* 10^(-4))`

Re = 2.0645