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Wed Sep 23 10:50:28 2009 UTC (10 years, 10 months ago) by jpye
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A silly little model that tests out Jose's interpolation code with air props.
1 REQUIRE "johnpye/datareader/testairprops.a4c";
2
3 (* Dittus-Boelter equation for fully-developed turbulent pipe flow *)
4 MODEL dittus;
5 T_w, T_m IS_A temperature;
6 air IS_A airprops(T_m);
7
8 Vel IS_A speed;
9 Vdot IS_A volume_rate;
10 mdot IS_A mass_rate;
11 A IS_A area;
12 D, L IS_A distance;
13 A = 0.25{PI}* D^2;
14 mdot = air.rho * Vdot;
15 Vdot = A*Vel;
16
17 Nu, Re, Pr IS_A factor;
18 Pr = air.cp * air.mu / air.k;
19
20 Re = air.rho * Vel * D / air.mu;
21
22 n IS_A factor;
23
24 Nu = 0.023 * Re^(4./5) * Pr^n;
25
26 for_heating: n = 0.3;
27 for_cooling: n = 0.4;
28
29 L_on_D IS_A factor;
30 L_on_D = L / D;
31
32 h IS_A heat_transfer_coefficient;
33 Nu * air.k = h * D;
34
35 Q IS_A energy_rate;
36 Q = h * L * 1{PI} * D * (T_w - T_m);
37
38 METHODS
39 METHOD on_load;
40 FIX mdot;
41 mdot := 0.04 {kg/s};
42 FIX D;
43 D := 12 {cm};
44 FIX L;
45 L := 5 {m};
46 FIX T_m;
47 T_m := 10 {K} + 273.15 {K};
48 FIX T_w;
49 T_w := 50 {K} + 273.15 {K};
50
51 L_on_D.lower_bound := 10;
52 L_on_D := 20;
53 Pr.lower_bound := 0.6;
54 Pr.upper_bound := 160;
55 Re.lower_bound := 10000;
56 Re := 20000;
57 for_heating.included := FALSE;
58 END on_load;
59 END dittus;

john.pye@anu.edu.au
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