blob: 3ad632e032f0903eb86ec590b3a6adc143d1f94e (
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
|
clear;
clc;
printf('FUNDAMENTALS OF HEAT AND MASS TRANSFER \n Incropera / Dewitt / Bergman / Lavine \n EXAMPLE 8.2 Page 499 \n'); //Example 8.2
// Length of tube needed to achieve the desired outlet temperature
//Local convection coefficient at the outlet
//Operating Conditions
m = .1; //[kg/s] mass flow rate of water
Ti = 20+273; //[K] Inlet temp
To = 60+273; //[K] Outlet temperature
Di = .02; //[m] Inner Diameter
Do = .04; //[m] Outer Diameter
q = 10^6; //[w/m^3] Heat generation Rate
Tsi = 70+273; //[K] Inner Surface Temp
//Table A.4 Air Properties T = 313 K
cp = 4179; //[J/kg.K] specific heat
L = 4*m*cp*(To-Ti)/(%pi*(Do^2-Di^2)*q);
//From Newtons Law of cooling, Equation 8.27, local heat convection coefficient is
h = q*(Do^2-Di^2)/(Di*4*(Tsi-To));
printf("\n Length of tube needed to achieve the desired outlet temperature = %.1f m \n Local convection coefficient at the outlet = %i W/m^2.K",L,h);
//END
|
