blob: f33a8cecd722d355b128373f1634bfec1c05c14d (
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
|
// A Texbook on POWER SYSTEM ENGINEERING
// A.Chakrabarti, M.L.Soni, P.V.Gupta, U.S.Bhatnagar
// DHANPAT RAI & Co.
// SECOND EDITION
// PART IV : UTILIZATION AND TRACTION
// CHAPTER 4: ILLUMINATION
// EXAMPLE : 4.3 :
// Page number 753-754
clear ; clc ; close ; // Clear the work space and console
// Given data
cp = 200.0 // cp of a lamp
per = 0.6 // Reflector directing light
D = 10.0 // Diameter(m)
h = 6.0 // Height at which lamp is hung(m)
// Calculations
flux = cp*4*%pi // Flux(lumens)
I_i = cp/h**2 // Illumination at the centre without reflector(lux)
d = (h**2+(D/2)**2)**0.5 // (m)
I_without = (cp/h**2)*(h/d) // Illumination at the edge without reflector(lux)
I_with = cp*4*%pi*per/(25*%pi) // Illumination at the edge with reflector(lux)
theta = acosd(h/d) // θ(°)
w = 2.0*%pi*(1-cosd(theta/2)) // ω(steradian)
phi = cp*w // Φ(lumens)
I_avg = phi/(25*%pi) // Average illumination over the area without reflector(lux)
// Results
disp("PART IV - EXAMPLE : 4.3 : SOLUTION :-")
printf("\nCase(i) : Illumination at the centre without reflector = %.2f lux", I_i)
printf("\n Illumination at the centre with reflector = %.1f lux", I_with)
printf("\nCase(ii): Illumination at the edge of the surface without reflector = %.2f lux", I_without)
printf("\n Illumination at the edge of the surface with reflector = %.1f lux", I_with)
printf("\nAverage illumination over the area without the reflector, I = %.3f lux\n", I_avg)
printf("\nNOTE: ERROR: Slight calculation mistake & more approximation in textbook solution")
|
