import math
#Operating Conditions
h = .05; #[W/m^2.K] Heat Convection coefficient
D = .02; #[m] Diameter of cylinder
Cas = 5*math.pow(10,-6); #[kmol/m^3] Surface molar Conc
Casurr = 0; #[kmol/m^3] Surrounding molar Conc
Ma = 128; #[Kg/kmol] Molecular weight
#calculations
#From Eqn 6.15
Na = h*(math.pi*D)*(Cas-Casurr);
na = Ma*Na;
#results
print '%s %.2e %s' %("\n\n Mass sublimation Rate is =",na," kg/s.m ");
#END
import math
#Operating Conditions
Dab = .288*math.pow(10,-4); #[m^2/s] Table A.8 water vapor-air (319K)
pas = .1; #[atm] Partial pressure at surface
pasurr = .02; #[atm] Partial pressure at infinity
y0 = .003; #[m] Tangent at y = 0 intercepts y axis at 3 mm
#calculations
#From Measured Vapor Pressure Distribution
delp = (0 - pas)/(y0 - 0); #[atm/m]
hmx = -Dab*delp/(pas - pasurr); #[m/s]
#results
print '%s %.4f %s' %("\n\n Convection Mass Transfer coefficient at prescribed location =",hmx," m/s");
#END
import math
#Operating Conditions
v = 1; #[m/s] Velocity of water
L = 0.6; #[m] Plate length
Tw1 = 300.; #[K]
Tw2 = 350.; #[K]
#Coefficients [W/m^1.5 . K]
Clam1 = 395;
Cturb1 = 2330;
Clam2 = 477;
Cturb2 = 3600;
#Water Properties at T = 300K
p1 = 997; #[kg/m^3] Density
u1 = 855*math.pow(10,-6); #[N.s/m^2] Viscosity
#Water Properties at T = 350K
p2 = 974; #[kg/m^3] Density
u2 = 365*math.pow(10,-6); #[N.s/m^2] Viscosity
Rec = 5*math.pow(10,5); #Transititon Reynolds Number
xc1 = Rec*u1/(p1*v); #[m]Transition length at 300K
xc2 = Rec*u2/(p2*v); #[m]Transition length at 350K
#calculations
#Integrating eqn 6.14
#At 300 K
h1 = (Clam1*math.pow(xc1,.5) /.5 + Cturb1*(math.pow(L,.8)-math.pow(xc1,.8))/.8)/L;
#At 350 K
h2 = (Clam2*math.pow(xc2,.5) /.5 + Cturb2*(math.pow(L,.8)-math.pow(xc2,.8))/.8)/L;
#results
print '%s %.2f %s %.2f %s' %("\n\n Average Convection Coefficient over the entire plate for the two temperatures at 300K =",h1," W/m^2.K and at 350K =",h2," W/m^2.K");
#END
#Operating Conditions
v = 160; #[m/s] Velocity of air
L = 0.04; #[m] Blade length
Tsurr = 1150+273.; #[K]
Ts = 800+273.; #[K] Surface Temp
q = 95000; #[W/m^2] Original heat flux
#calculations
#Case 1
Ts1 = 700+273.; #[K] Surface Temp
q1 = q*(Tsurr-Ts1)/(Tsurr-Ts);
#Case 2
L2 = .08; #[m] Length
q2 = q*L/L2; #[W/m^2] Heat flux
#results
print '%s %d %s' %("\n\n (a) Heat Flux to blade when surface temp is reduced =",q1/1000. ," KW/m^2")
print '%s %.2f %s' %("\n (b) Heat flux to a larger turbine blade = ",q2/1000. ,"KW/m^2");
#END
import math
#Operating Conditions
v = 100; #[m/s] Velocity of air
Tsurr = 20+273.; #[K] Surrounding Air Temperature
L1 = 1; #[m] solid length
Ts = 80+273.; #[K] Surface Temp
qx = 10000; #[W/m^2] heat flux at a point x
Txy = 60+273.; #[K] Temp in boundary layer above the point
#Table A.4 Air Properties at T = 323K
v = 18.2*math.pow(10,-6); #[m^2/s] Viscosity
k = 28*math.pow(10,-3); #[W/m.K] Conductivity
Pr = 0.7; #Prandttl Number
#Table A.6 Saturated Water Vapor at T = 323K
pasat = 0.082; #[kg/m^3]
Ma = 18; #[kg/kmol] Molecular mass of water vapor
#Table A.8 Water Vapor-air at T = 323K
Dab = .26*math.pow(10,-4); #[m^2/s]
#calculations
#Case 1
Casurr = 0;
Cas = pasat/Ma; #[kmol/m^3] Molar conc of saturated water vapor at surface
Caxy = Cas + (Casurr - Cas)*(Txy - Ts)/(Tsurr - Ts);
#Case 2
L2 = 2.;
hm = L1/L2 * Dab/k * qx/(Ts-Tsurr);
Na = hm*(Cas - Casurr);
#results
print '%s %.4f %s' %("\n (a) Water vapor Concentration above the point =",Caxy,"Kmol/m^3 \n")
print '%s %.2e %s' %("(b) Molar flux to a larger surface = ",Na,"Kmol/s.m^2");
#END
import math
#Operating Conditions
Tsurr = 40+273.; #[K] Surrounding Air Temperature
#Volatile Wetting Agent A
hfg = 100; #[kJ/kg]
Ma = 200; #[kg/kmol] Molecular mass
pasat = 5000; #[N/m^2] Saturate pressure
Dab = .2*math.pow(10,-4); #[m^2/s] Diffusion coefficient
#Table A.4 Air Properties at T = 300K
p = 1.16; #[kg/m^3] Density
cp = 1.007; #[kJ/kg.K] Specific Heat
alpha = 22.5*math.pow(10,-6)#[m^2/s]
R = 8.314; #[kJ/kmol] Universal Gas Constt
#calculations
#Applying Eqn 6.65 and setting pasurr = 0
# Ts^2 - Tsurr*Ts + B = 0 , where the coefficient B is
B = Ma*hfg*pasat*math.pow(10,-3) /(R*p*cp*math.pow((alpha/Dab),(2./3.)));
Ts = (Tsurr + math.sqrt(Tsurr*Tsurr - 4*B))/2. ;
#results
print '%s %.1f %s' %("\n Steady State Surface Temperature of Beverage =",Ts-273.,"degC");
#END