Answer to Question #113794 in Mechanical Engineering for Eric Likando

Question

{a }Oil flows in a pipe 100 mm bore diameter with a Reynolds’ Number of 500 .what is the density {b}While solving a problem, a person ended up with the following equation at some stage
: E = 25 kJ + 7 kJ/kg, where E is the total energy and has the unit of kilojoules. Determine how to correct the error and discuss what may have caused it. .

Answer 1

QUESITION A

Given;

Pipe diameter (d) = 100 mm

Reynolds’ Number = 500

Assume

Oil viscosity  = 0.08Ns/m²

Velocity u_m = 0.5m/s

R_e =

p = 800kg/m3

 

QUESTION B

E = 25kJ + 7kJ/kg

E has the unit of kilojoules. The cause of this problem is error in dimension of this formula. ince do not have the same units, therefore, they can’t be added to obtain the total energy. To correct the answer we have to multiply the number 7 by mass of person. Then expression dimensionally homogenous.

Then expression is dimensionally homogenous, therefore they can be added to obtain the total energy.