# Diff of /trunk/models/johnpye/cavity.a4c

revision 353 by johnpye, Wed Mar 1 13:53:45 2006 UTC revision 354 by johnpye, Fri Mar 3 04:47:59 2006 UTC
# Line 16  ATOM energy_flux REFINES solver_var Line 16  ATOM energy_flux REFINES solver_var
16      nominal := 1000{W/m^2};      nominal := 1000{W/m^2};
17  END energy_flux;  END energy_flux;
18
19    ATOM heat_transfer_coefficient REFINES solver_var
20            DIMENSION M/T^3/TMP
21            DEFAULT 5{W/m^2/K};
22
23        lower_bound := 0{W/m^2/K};
24        upper_bound := 1e50{W/m^2/K};
25        nominal := 5{W/m^2/K};
26
27    END heat_transfer_coefficient;
28
29  MODEL cavity;  MODEL cavity;
30      W,B,S,N,C,E,D IS_A distance;      W,B,S,N,C,E,D IS_A distance;
31      theta, phi, psi IS_A angle;      theta, phi, psi IS_A angle;
# Line 33  MODEL cavity; Line 43  MODEL cavity;
43      C^2 = E^2 + S^2 - 2* E * S * cos(psi);      C^2 = E^2 + S^2 - 2* E * S * cos(psi);
44
45      F_WN = (W+N-C)/2/W;      F_WN = (W+N-C)/2/W;
46      F_WW = (2*E-2*D)/2/W;      F_WW = (2*E-2*D)/2/W; (* from top to directly opp part of bottom *)
47      F_WB = 1 - 2 * F_WN;      F_WB = 1 - 2 * F_WN;
48      F_WS = (1 - 2 * F_WN - F_WB)/2;      F_WS = (1 - 2 * F_WN - F_WB)/2;
49      F_NB = (N+B-C)/2/N;      F_NB = (N+B-C)/2/N;
# Line 42  MODEL cavity; Line 52  MODEL cavity;
52      F_BN = F_NB*N/B;      F_BN = F_NB*N/B;
53      F_NN = 1 - F_NW - F_NB;      F_NN = 1 - F_NW - F_NB;
54      F_BW = F_WB*W/B;      F_BW = F_WB*W/B;
55
56      n IS_A set OF symbol_constant;      n IS_A set OF symbol_constant;
57      n :== ['W','B','L','R'];      n :== ['W','B','L','R'];
58
# Line 91  MODEL cavity; Line 101  MODEL cavity;
101      FOR i IN n CREATE      FOR i IN n CREATE
102          q[i] * (1-eps[i]) = (E_b[i] - J[i]) * (eps[i]*A[i]);          q[i] * (1-eps[i]) = (E_b[i] - J[i]) * (eps[i]*A[i]);
103      END FOR;      END FOR;
104
105  METHODS  METHODS
106  METHOD default_self;  METHOD default_self;
107      RUN reset; RUN values; RUN bound_self;      RUN reset; RUN values; RUN bound_self;
# Line 126  METHOD values; Line 136  METHOD values;
136
137  END values;  END values;
138
END cavity;
139    END cavity;
140
141    (*========================================
142        This model adds external convection
143        coefficients to the model, and an
144        ambient temperature.
145
146        We also calculate the F_rad correlation
147        parameter.
148    *)
149    MODEL cavity_losses REFINES cavity;
150        h_B, h_N IS_A heat_transfer_coefficient;
151        T_amb IS_A temperature;
152
153        - q['B'] = h_B * B * (T['B'] - T_amb);
154        - q['L'] = h_N * N * (T['L'] - T_amb);
155        - q['R'] = h_N * N * (T['L'] - T_amb);
156
159
160        - q['B'] = F_rad * eps['W'] * 1{SIGMA_C} * (T['W']^4 - T['B']^4);
161
162        - q['B'] = F_rad_1 * 1{SIGMA_C} * (T['W']^4 - T['B']^4) /
163            (1/eps['B'] + 1/eps['W'] - 1);
164
165    METHODS
166    METHOD specify;
167        FIX T['W'], T_amb;
168        FIX h_B, h_N;
169        FIX W,D,theta;
170        FIX eps[n];
171    END specify;
172    METHOD values;
173        T['W'] := 550 {K};
174        T_amb := 290 {K};
175        W := 500 {mm};
176        D := 300 {mm};
177        theta := 30 {deg};
178        eps['W'] := 0.49;
179        eps['B'] := 0.9;
180        eps['L','R'] := 0.1;
181        h_B := 10 {W/m^2/K};
182        h_N := 0.5 {W/m^2/K};
183        (* free values *)
184        T['L','R'] := 500 {K};
185        T['B'] := 400 {K};
186    END values;
187    END cavity_losses;

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