diff options
Diffstat (limited to '2510/CH12')
| -rwxr-xr-x | 2510/CH12/EX12.10/Ex12_10.sce | 16 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.11/Ex12_11.sce | 11 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.12/Ex12_12.sce | 29 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.13/Ex12_13.sce | 11 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.2/Ex12_2.sce | 9 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.4/Ex12_4.sce | 11 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.5/Ex12_5.sce | 39 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.6/Ex12_6.sce | 19 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.7/Ex12_7.sce | 18 | ||||
| -rwxr-xr-x | 2510/CH12/EX12.9/Ex12_9.sce | 16 |
10 files changed, 179 insertions, 0 deletions
diff --git a/2510/CH12/EX12.10/Ex12_10.sce b/2510/CH12/EX12.10/Ex12_10.sce new file mode 100755 index 000000000..5de5b331b --- /dev/null +++ b/2510/CH12/EX12.10/Ex12_10.sce @@ -0,0 +1,16 @@ +//Variable declaration: +//From example 12.9: +Ts1 = 102.0 //Original surface temperature (°C) +Ts2 = 103.0 //New surface temperature (°C) +Tsat = 100.0 //Saturation temperature (°C) + +//Calculation: +DTe1 = (Ts1 - Tsat) //Original excess temperature (°C) +DTe2 = (Ts2 - Tsat) //New excess temperature (°C) + +//Result: +printf("The original excess temperature is: DTe = %f °C .",DTe1) +printf("The new excess temperature is: DTe = %f °C .",DTe2) +if ((DTe1 < 5) & (DTe2 < 5)) then + printf("The assumption of the free convection mechanism is valid since DTe < 5°C.") +end diff --git a/2510/CH12/EX12.11/Ex12_11.sce b/2510/CH12/EX12.11/Ex12_11.sce new file mode 100755 index 000000000..85c0af1ef --- /dev/null +++ b/2510/CH12/EX12.11/Ex12_11.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 12.9: +Cp = 4127.0 //heat capacity (J/kg . K) +DTe = 3.0 //New excess temperature (°C) +h_vap = 2.26*10**6 //latent heat of vaporization (J/kg) + +//Calculation: +Ja_L = Cp*DTe/h_vap //Liquid Jakob number + +//Result: +printf("The liquid Jakob number is : %.5f",Ja_L) diff --git a/2510/CH12/EX12.12/Ex12_12.sce b/2510/CH12/EX12.12/Ex12_12.sce new file mode 100755 index 000000000..d07af2ad0 --- /dev/null +++ b/2510/CH12/EX12.12/Ex12_12.sce @@ -0,0 +1,29 @@ +//Variable declaration: +Ts = 106.0 //Surface temperature (°C) +Tsat = 100.0 //Saturation temperature (°C) + +//Calculation: +DTe = Ts-Tsat //Excess temperature (°C) +//From table 12.5: +C1 = 5.56 //Constant C1 +n1 = 3.0 //Constant n1 +C2 = 1040.0 //Constant C2 +n2 = 1.0/3.0 //Constant n2 +P = 1.0 //Absolute pressure (atm) +Pa = 1.0 //Ambient absolute pressure (atm) + +//Calculation: +h1 = C1*DTe**n1*(P/Pa)**0.4 //Boiling water heat transfer coefficient (W/m^2) +Qs1 = h1*DTe //Surface flux (W/m^2) +h2 = C2*DTe**n2*(P/Pa)**0.4 //Second Boiling water heat transfer coefficient (W/m^2) +Qs2 = h2*DTe //Second Surface flux (W/m^2) + +//Result: + +if (Qs1/10**3 > 15.8 & Qs1/10**3 < 236) then + printf("The boiling regime is : %.1f kW/m^2 .",Qs1/10**3) + printf("The heat transfer coefficient is : %.0f W/m^2 .",h1) +elseif (Qs1/10**3 < 15.8) then + printf("The boiling regime is : %.2f kW/m^2 .",Qs2/10**3) + printf("The heat transfer coefficient is : %.0f W/m^2.",h2) +end diff --git a/2510/CH12/EX12.13/Ex12_13.sce b/2510/CH12/EX12.13/Ex12_13.sce new file mode 100755 index 000000000..393070ec9 --- /dev/null +++ b/2510/CH12/EX12.13/Ex12_13.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 12.12: +Qs1 = 11340.0 //Surface flux (W/m^2) +D = 0.3 //Diameter of electric heater (m) + +//Calculation: +A = %pi*(D/2.0)**2 //Surface area of heater (m^2) +Qs = Qs1*A //Heat transfer rate (W) + +//Result: +printf("The rate of heat transfer is : %.0f W.",Qs) diff --git a/2510/CH12/EX12.2/Ex12_2.sce b/2510/CH12/EX12.2/Ex12_2.sce new file mode 100755 index 000000000..ba8669f3b --- /dev/null +++ b/2510/CH12/EX12.2/Ex12_2.sce @@ -0,0 +1,9 @@ +//Variable declaration: +C = 1 //Number of constituents +P = 1 //Number of phases + +//Calculation: +F = C-P+2 //Number of degrees of freedom + +//Result: +printf("The number of degrees of freedom is : %.2f .",F) diff --git a/2510/CH12/EX12.4/Ex12_4.sce b/2510/CH12/EX12.4/Ex12_4.sce new file mode 100755 index 000000000..b30b7a3a8 --- /dev/null +++ b/2510/CH12/EX12.4/Ex12_4.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From steam tables: +U1 = 1237.1 //Internnal energy of gas (Btu/lb) +U2_g = 1112.2 //Internal energy of gas (Btu/lb) +U2_l = 343.15 //Internal energy of liquid (Btu/lb) + +//Calculation: +Q = 0.5*(U2_g+U2_l)-1*U1 //Heat removed (Btu/lb) + +//Result: +printf("Heat removed from the system during the process is : %.1f Btu/lb.",Q) diff --git a/2510/CH12/EX12.5/Ex12_5.sce b/2510/CH12/EX12.5/Ex12_5.sce new file mode 100755 index 000000000..b35245a04 --- /dev/null +++ b/2510/CH12/EX12.5/Ex12_5.sce @@ -0,0 +1,39 @@ +//Variable declaration: +T1 = 99.0 //Mean film temperature (°C) +T2 = 98.0 //Plate surface temperature (°C) +g = 9.807 //Gravitational acceleration (m/s^2) +//From Appendix: +T3 = 100.0 //Saturation temperatre (°C) +h_vap1 = 970.3 //Latent heat of steam in Btu/lb (Btu/lb) +h_vap2 = 2.255*10**6 //Latent heat of steam in J/kg (J/kg) +p_v = 0.577 //Density of steam (kg/m^3) +p_l = 960.0 //Density of liquid water condensate (kg/m^3) +mu_l = 2.82*10**-4 //Absolute viscosity of liquid water condensate (kg/m.s) +k = 0.68 //Thermal conductivity of water (W/m.K) +//From table 12.2 +Z = 0.4 //Height of rectangular plate (m) +Pw = 0.2 //Wetted perimeter of rectangular plate (m) +syms h //Average heat transfer coefficient (W/m^2.K) + +//Calculation: +A = Z*Pw //Heat transfer area of plate (m^2) +R = A/Pw //Ratio A/Pw (m) +v_l = mu_l/p_l //Kinematic viscosity of liquid water condensate (m^2/s) +Co1 = (h/k)*(v_l**2/g/(1-p_v/p_l))**(1/3) //Condensation number (in terms of the average heat transfer coefficient) +Re = 4*h*Z*(T3-T2)/(mu_l*h_vap2) //Reynolds number in terms of the average heat transfer coefficient +//From equation 12.14: +CO1 = 0.0077*Re**Z //Co in terms of Reynolds number for flow type 1 +x1 = solve(h,Co1-CO1) //Solving heat transfer coefficient (W/m^2.K) +h1 =x1(2); //Average heat transfer coefficient for flow type 1 (W/m^2.K) +Re1 = subst(h1,h,Re) //Reynolds number for flow type 1 +CO2 = 1.874*Re**(-1/3) //Co in terms of Reynolds number for flow tupe 2 +x2 = solve(Co1-CO2,h) //Solving average heat transfer coefficient for flow type 2 (W/m^2.K) +h2 = x2(1); //Average heat transfer coefficient for flow type 2 (W/m^2.K) +Re2 = subst(h2,h,Re) //Reynolds number for flow type 2 +h2 = round(h2*10**-1)/10**-1 + +//Result: +printf("The type of condensation flow type 2 is laminar.") +disp("And the condensation heat transfer coefficient is : ") +disp(h2) +disp("W/m^2.K.") diff --git a/2510/CH12/EX12.6/Ex12_6.sce b/2510/CH12/EX12.6/Ex12_6.sce new file mode 100755 index 000000000..333baca4f --- /dev/null +++ b/2510/CH12/EX12.6/Ex12_6.sce @@ -0,0 +1,19 @@ +//Variable declaration: +//From example 12.5: +Re = 73.9 //Reynolds number +mu_l = 2.82*10**-4 //Absolute viscosity of liquid water condensate (kg/m.s) +Pw = 0.2 //Wetted perimeter of rectangular plate (m) +h = 14700.0 //Heat transfer coefficient (W/m^2.K) +T_sat = 100.0 //Saturation temperature (°C) +Ts = 98.0 //Surface temperature (°C) +A = 0.2*0.4 //Heat transfer area of plate (m^2) + +//Calculation: +m1 = Re*mu_l/4.0 //Mass flow rate of condensate (kg/m.s) +m = Pw*m1 //Mass flow rate of condensate (kg/s) +Co = (3.038*10**-5)*h //Condensation number +Q = h*A*(T_sat-Ts) //Heat transfer rate (W) + +//Result: +printf("1. The mass flow rate of condensate is : %.4f kg/m.s.",m1) +printf("2. The heat transfer rate is : %.2f kW.",Q/10**3) diff --git a/2510/CH12/EX12.7/Ex12_7.sce b/2510/CH12/EX12.7/Ex12_7.sce new file mode 100755 index 000000000..90331fcc8 --- /dev/null +++ b/2510/CH12/EX12.7/Ex12_7.sce @@ -0,0 +1,18 @@ +//Variable declaration: +T_sat = 126.0 //Saturation temperature (°F) +T = 64.0 //Surface temperature of tube (°F) +g = 32.2 //Gravitational acceleration (ft^2/s) +D = 4.0/12.0 //Outside diameter of tube (ft) + +//Calculation: +Tf = (T_sat+T)/2.0 //Mean film temperature (°F) +//From approximate values of key properties: +h_vap = 1022.0 //Latent heat of steam (Btu/lb) +p_v = 0.00576 //Density of steam (lb/ft^3) +p_l = 62.03 //Density of liquid (lb/ft^3) +k_l = 0.364 //Thermal conductivity of liquid (Btu/h.ft.°F) +mu_l = 4.26*10**-4 //Absolute viscosity of liquid water condensate (lb/ft.s) +h = 0.725*((p_l*(p_l-p_v)*g*h_vap*k_l**3)/(mu_l*D*(T_sat-T)/3600.0))**(1.0/4.0) //Average heat transfer coefficient (Btu/h.ft^2.°F) + +//Result: +printf("The average heat transfer coefficient is : %.1f Btu/h.ft^2.°F.",h) diff --git a/2510/CH12/EX12.9/Ex12_9.sce b/2510/CH12/EX12.9/Ex12_9.sce new file mode 100755 index 000000000..0a6ab11ee --- /dev/null +++ b/2510/CH12/EX12.9/Ex12_9.sce @@ -0,0 +1,16 @@ +//Variable declaration: +Qs1 = 9800.0 //Heat flux (W/m^2) +Ts1 = 102.0 //Original surface temperature (°C) +Ts2 = 103.0 //New surface temperature (°C) +Tsat = 100.0 //Saturation temperature (°C) + +//Calculation: +h1 = Qs1/(Ts1-Tsat) //Original heat transfer coefficient (W/m^2.K) +DT1 = (Ts1 - Tsat) //Original excess temperature (°C) +DT2 = (Ts2 - Tsat) //New excess temperature (°C) +n = 0.25 //Value of n for laminar flow +h2 = h1*(DT2/DT1)**(n) //New heat transfer coefficient (W/m^2.K) +Qs2 = h2*(Ts2-Tsat) //New heat flux (W/m^2) + +//Result: +printf("The new heat flux is : %.0f W/m^2.K .",Qs2) |