blob: 683fea477770e8cdca59f0617d425f4bb25ede9a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
clear;
clc;
// A Textbook on HEAT TRANSFER by S P SUKHATME
// Chapter 9
// Mass Transfer
// Example 9.7(a)
// Page 366
printf("Example 9.7(a), Page 366 \n \n");
D = 0.04 ; // [m]
V = 1.9 ; // [m/s]
// (a) Colburn anology and Gnielinski equation
// Properties of air at 27 degree C
v = 15.718*10^-6 ; // [m^2/s]
rho = 1.177 ; // [kg/m^3]
Pr = 0.7015 ;
Cp = 1005 ; // [J/kg K]
k = 0.02646 ; // [W/m K]
// From Table 9.2
Dab = 2.54 * 10^-5 ; // [m^2/s]
Sc = v/Dab ;
Re = V*D/v;
// The flow is turbulent and eqn 9.6.5 may be applied
// let r = h/h_m
r = rho*Cp*((Sc/Pr)^(2/3));
// From Blasius equation 4.6.4a
f = 0.079*Re^(-0.25);
// Substituting this value into Gnielinski equation 5.3.2
Nu = [(f/2)*(Re-1000)*Pr]/[1+12.7*((f/2)^(1/2))*((Pr^(2/3))-1)];
h = Nu*k/D;
h_m = h/r; // [m/s]
printf("h_m using Colburn anology and Gnielinski equation = %f \n",h_m);
|
