From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 617/CH4/EX4.1/Example4_1.sci | 35 +++++++++++++++++++++++++++++++++++ 617/CH4/EX4.2/Example4_2.sci | 33 +++++++++++++++++++++++++++++++++ 617/CH4/EX4.3/Example4_3.sci | 23 +++++++++++++++++++++++ 617/CH4/EX4.4/Example4_4.sci | 13 +++++++++++++ 617/CH4/EX4.5/Example4_5.sci | 12 ++++++++++++ 617/CH4/EX4.6/Example4_6.sci | 26 ++++++++++++++++++++++++++ 617/CH4/EX4.7/Example4_7.sci | 27 +++++++++++++++++++++++++++ 617/CH4/EX4.8/Example4_8.sci | 27 +++++++++++++++++++++++++++ 617/CH4/EX4.9/Example4_9.sci | 25 +++++++++++++++++++++++++ 9 files changed, 221 insertions(+) create mode 100755 617/CH4/EX4.1/Example4_1.sci create mode 100755 617/CH4/EX4.2/Example4_2.sci create mode 100755 617/CH4/EX4.3/Example4_3.sci create mode 100755 617/CH4/EX4.4/Example4_4.sci create mode 100755 617/CH4/EX4.5/Example4_5.sci create mode 100755 617/CH4/EX4.6/Example4_6.sci create mode 100755 617/CH4/EX4.7/Example4_7.sci create mode 100755 617/CH4/EX4.8/Example4_8.sci create mode 100755 617/CH4/EX4.9/Example4_9.sci (limited to '617/CH4') diff --git a/617/CH4/EX4.1/Example4_1.sci b/617/CH4/EX4.1/Example4_1.sci new file mode 100755 index 000000000..c528ae3b5 --- /dev/null +++ b/617/CH4/EX4.1/Example4_1.sci @@ -0,0 +1,35 @@ +clc(); +clear; + +// To find heat changes and temperature change on heating of a concrete wall + +b=9; // Thickness of the wall in ft +A=5; // Area of wall +k=0.44; // Thermal conductivity in Btu/hr-ft-degF +Cp=.202; // Specific heat in Btu/lbm-degF +rho=136; // Density in lb/ft^3 + +function[t]=templength(x); // Temperature function in terms of length + t = 90 - 80*x +16*x^2 +32*x^3 -25.6*x^4; + funcprot(0); +endfunction +tgo = derivative(templength,0); // Temperature gradient at x=0ft +tgl = derivative(templength,9/12); // Temperature gradient at x=9/12ft + +qo = -k*A*tgo; // Heat entering per unit time in Btu/hr +printf("Heat entering per unit time is %.2f Btu/hr \n",qo); +ql = -k*A*tgl; // Heat coming out per unit time in Btu/hr +printf(" Heat coming per unit time is %.2f Btu/hr \n",ql); +q3 = qo-ql; //Heat energy stored in Btu/hr +printf(" Heat energy stored in wall is %.2f Btu/hr \n",q3); + +a=k/(rho*Cp); // Thermal diffusivity +function[t2]=doublederivative(y); // Derivative of tempearture with respect to length in degF/ft + t2= -80+32*y+96*y^2-102.4*y^3; + funcprot(0); +endfunction +timeder0=a*derivative(doublederivative,0); // derivative of temperature wrt time at x=0 in degF +printf(" Time derivative of temperature wrt time at x=0ft is %.2f degF/hr\n",timeder0); +timeder1=a*derivative(doublederivative,9/12); // derivative of temperature wrt time at x=9/12 in degF +printf(" Time derivative of temperature wrt time at x=9/12ft is %.2f degF/hr\n",timeder1); + diff --git a/617/CH4/EX4.2/Example4_2.sci b/617/CH4/EX4.2/Example4_2.sci new file mode 100755 index 000000000..bdc8f46e2 --- /dev/null +++ b/617/CH4/EX4.2/Example4_2.sci @@ -0,0 +1,33 @@ +clc(); +clear; +// To find heat changes and temperature change on heating of a concrete wall +b=9; // thickness of the wall in ft +A=5; // area of wall in ft^2 +k=0.44; // Thermal conductivity in Btu/hr-ft-degF +Cp=.202; // Specific heat in Btu/lbm-degF +rho=136; // density in lb/ft^3 + +function[t]=templength(x); + t = 90 - 8*x-80*x^2; + funcprot(0); +endfunction +tgo = derivative(templength,0); // temperature gradient at x=0ft +tgl = derivative(templength,9/12); // temperature gradient at x=9/12ft + +qo = -k*A*tgo; // Heat entering per unit time in Btu/hr +printf("Heat entering per unit time is %.2f Btu/hr \n",qo); +ql = -k*A*tgl; // Heat coming out per unit time in Btu/hr +printf(" Heat coming per unit time is %.2f Btu/hr \n",ql); +q3 = qo-ql; //Heat energy stored in Btu/hr +printf(" Heat energy stored in wall is %.2f Btu/hr \n",q3); + +a=k/(rho*Cp); // Thermal diffusivity in ft^2/hr +function[t2]=doublederivative(y); // derivative of tempearture with respect to length in degF/ft + t2= -8-160*x; + funcprot(0); +endfunction; +timeder0=a*derivative(doublederivative,0); // derivative of temperature wrt time at x=0 in degF +printf(" Time derivative of temperature wrt time at x=0ft is %.2f degF/hr\n",timeder0); +timeder1=a*derivative(doublederivative,9/12); // derivative of temperature wrt time at x=9/12 in degF +printf(" Time derivative of temperature wrt time at x=9/12ft is %.2f degF/hr\n",timeder1); +printf(" Teperature at each part of wall decreases equally"); diff --git a/617/CH4/EX4.3/Example4_3.sci b/617/CH4/EX4.3/Example4_3.sci new file mode 100755 index 000000000..bc85a2de5 --- /dev/null +++ b/617/CH4/EX4.3/Example4_3.sci @@ -0,0 +1,23 @@ +clc(); +clear; + +// To find the tempearure and heat low in case of sudden heat change + +t = 10; // time elapsed in hr +Ti= 70; // tempearature of wall initially in degF +Ts = 1500; // temperature of surface when suddenly changed in degF +a = 0.03; // thermal diffusivity in ft^2/hr +k = 0.5; // thermal conductivity in Btu/hr-ft-degF +A = 10; // area of wall in sq ft +x = 7/12; // distance from surface where tempearture is to be found in ft +f = x/(2*sqrt(a*t)); +// From gaussian error function table erf can be found +errorf = 0.55; // Referred from table + +T = Ts+(Ti-Ts)*errorf; +printf("Temperaure at a distance of 7/12ft from surface is %.1f degF \n",T); +q = -k*A*(Ti-Ts)*exp(-x^2/(4*a*t))/sqrt(t*%pi*a); // heat flow rate at a distance +qtot = -k*A*(Ti-Ts)*2*sqrt(t/(%pi*a)); // total heat flowing after 10 hrs in Btu +printf(" Heat flowing at a distance of 7/12 ft from surface is %d Btu/hr\n",q); +printf(" Total heat flow after 10hrs is %f Btu",%pi); + diff --git a/617/CH4/EX4.4/Example4_4.sci b/617/CH4/EX4.4/Example4_4.sci new file mode 100755 index 000000000..539502ccf --- /dev/null +++ b/617/CH4/EX4.4/Example4_4.sci @@ -0,0 +1,13 @@ +clc(); +clear; +// To find the temperature at center of sphere on sudden temperature change +d = 16/12; // Diameter of sphere in ft +t = 20/60; // Time elapsed in hr +a = 0.31; // thermal diffusivity of steel in ft^2/hr +Ti = 80; // Temperature of steel sphere initially in degF +Ts = 1200; // Temperature of surface suddenly changed in degF +s = 4*a*t/d^2; // A parameter +// From table the value of F(s) can be known +Fs=0.20; +Tc = Ts+(Ti-Ts)*Fs; // Tempearture at the center of sphere in degF +printf("The tempearture at the center of steel sphere after 20 mins is %d degF",Tc); \ No newline at end of file diff --git a/617/CH4/EX4.5/Example4_5.sci b/617/CH4/EX4.5/Example4_5.sci new file mode 100755 index 000000000..65a309602 --- /dev/null +++ b/617/CH4/EX4.5/Example4_5.sci @@ -0,0 +1,12 @@ +clc(); +clear; +// To estimate the time lag of temperature (sine) wave +t = 24; // Time period of tempearture wave in hr +k = 0.6; // Thermal conductivity of wall in Btu/hr-ft-degF +Cp = 0.2; // Specific heat capacity of wall in Btu/lb-degF +y = 110; // specific gravity in lb/ft^3 +x = 8/12; // Distance from surface in ft +a = k/(y*Cp); // Thermal diffusivity in ft^2/hr +n=1/t; // frequency in /hr +delr = x/(2*sqrt(a*%pi*n); // Time lag in hr +printf("Time lag of the temperature at a point 8 in from surface is %.1f hr", delr; diff --git a/617/CH4/EX4.6/Example4_6.sci b/617/CH4/EX4.6/Example4_6.sci new file mode 100755 index 000000000..55ce882fa --- /dev/null +++ b/617/CH4/EX4.6/Example4_6.sci @@ -0,0 +1,26 @@ +clc(); +clear; + +// To calculate the range in temperatures at different depths +T1=-15; // Min temperature at surface in degF +T2=25; // Max temperature at surface in degF +t=24; // time gap in hrs +k=1.3; // thermal conductivity in Btu/hr-ft-degF +Cp=0.4; // heat capacity in lb/ft-degF +y=126.1; // specific gravity in lb/ft^3 +n=1/t; // frequency in /hr +Tm=(T1+T2)/2; +a=k/(y*Cp); // thermal diffusivity in ft^2 + +x1=2; +x2=6; +th0=(T1-T2)/2; +th1=th0*-exp(-x1*sqrt(%pi*n/a)); // temperature range at 2 ft depth +th2=th0*-exp(-x2*sqrt(%pi*n/a)); // temperature range at 6 ft depth +printf("Amplitude of tempearture at 2ft deep is %.2f degF\n",th1); +printf(" Amplitude of tempearture at 6ft deep is %.2f degF\n",th2); +printf(" At a depth of 2ft , temperature varies from 4.78 degF to 5.22 degF and at a depth of 6 ft, temperature remains constant at 5 degF"); +delr1=x1/2*sqrt(1/(a*%pi*n)); // time lag at 2 ft depth +delr2=x2/2*sqrt(1/(a*%pi*n)); // time lag at 6 ft depth +printf(" Lag of temperature wave at a depth 2 ft is %.1f hr \n",delr1); +printf(" Lag of temperature wave at a depth 6 ft is %.1f hr \n",delr2); \ No newline at end of file diff --git a/617/CH4/EX4.7/Example4_7.sci b/617/CH4/EX4.7/Example4_7.sci new file mode 100755 index 000000000..b23f47eb2 --- /dev/null +++ b/617/CH4/EX4.7/Example4_7.sci @@ -0,0 +1,27 @@ +clc(); +clear; + +// To calculate the range in temoperatures at different depths +T1=10; // Min temperature at surface in degF +T2=-10; // Max temperature at surface in degF +t1=24; +t2=5; // Time gap in hrs +k=0.3; // Thermal conductivity in Btu/hr-ft-degF +Cp=0.47; // Heat capacity in lb/ft-degF +y=100; // Specific gravity in lb/ft^3 +n1=1/t1; // Frequency in /hr +Tm=(T1+T2)/2;a=k/(y*Cp); // thermal diffusivity in ft^2 +n=1/t1; // Frequency in /sec +x1=1; +x2=1; // Depth in ft +th0=(T1-T2)/2;th1=th0*exp(-x1*sqrt(%pi*n/a)); // temperature range at 2 ft depth +th2=th0*exp(-x2*sqrt(%pi*n/a)); // Temperature range at 6 ft depth +printf("Amplitude of tempearture at 2ft deep is %.2f degF\n",th1); +delr1=x1/2*sqrt(1/(a*%pi*n)); // Time lag at 2 ft depth +printf(" Lag of temperature wave at a depth 2 ft is %.1f hr \n",delr1); + // To calculate the temperature at a depth of 1 ft , 5 hr after the srface temperature reaches the minimum temperature + r=3/(4*n); // Time at which minimum surface temperature occurs for the first time in hr + r1=r+5; // Time ar which temperature is to be found out in degF + th3=th0*exp(-x1*sqrt(%pi*n/a))*sin(2*%pi*r1/24-4.53); + Tr=Tm+th3; // Temperature to be found out in degF + printf(" The temperaure at 1 ft depth is %.2f degF \n",Tr); \ No newline at end of file diff --git a/617/CH4/EX4.8/Example4_8.sci b/617/CH4/EX4.8/Example4_8.sci new file mode 100755 index 000000000..ad587580d --- /dev/null +++ b/617/CH4/EX4.8/Example4_8.sci @@ -0,0 +1,27 @@ +clc(); +clear; + +// to compute the temperatures at different points +a=0.02; // thermal diffusivity in ft^2/hr +M=4; // the value of 4 is selected for M +x=9/12; // thickness of wall in ft +delx=1.5/12; +delr=delx^2/(a*M); // at time interval the heat transfeered will change the temperature of sink from tb2 to tb2o +printf("The time interval is to be of %.3f hr \n",delr); + +t1o=370; t2o=435; t3o=480; t4o=485; t5o=440; t6o=360; t7o=250; + +// tempetaures at different positions at wall in degF initially +// we know qo=Z*delx*dely*rho*Cp(tb2'-tb2)/delr So on solving equations we get tb2'=(tb1+tb3+ta2+tc2)/4 +// using above formula, temperaures at different positions as shown below can be calculated in degF + +ta=[370 430 470 473 431 352 250]; +tb=[370 425 461 462 422 346 250]; +tc=[370 420 452 452 413 341 250]; +td=[370 415 444 442 404 336 250]; +printf(" The temperatures at different positions 0.78 hr after, are as follows \n"); +for i=1:7 +printf(" The temperature at point %d is %d degF \n",i,td(i)); +end + + diff --git a/617/CH4/EX4.9/Example4_9.sci b/617/CH4/EX4.9/Example4_9.sci new file mode 100755 index 000000000..8456fd2f8 --- /dev/null +++ b/617/CH4/EX4.9/Example4_9.sci @@ -0,0 +1,25 @@ +clc(); +clear; + +// to compute the temperatures at different points + +a=0.53; // thermal diffusivity in ft^2/hr +M=4; // the value of 4 is selected for M +x=6/12; // thickness of wall in ft +delx=2/12; +delr=delx^2/(a*M); // at time interval the heat transfeered will change the temperature of sink from tb2 to tb2o +printf("the time interval is to be of %.3f hr \n",delr); + +// the temperature is constant in the whole wall initiallt 100 degF and afterwards it changes to 1000 degF. +// we know qo=Z*delx*dely*rho*Cp(tb2'-tb2)/delr So on solving equations we get tb2'=(tb1+tb3+ta2+tc2)/4 +// Using above formula we can calculate the different temperatures as given below in degF + +ta=[100 550 775 888 944]; +tb=[100 550 775 888 944]; +tc=[100 550 775 888 944]; +td=[100 550 775 888 944]; +printf(" the temperatures at different positions 0.052 hr after, are as follows \n"); +printf(" the temperature at point a is %d degF \n",ta(5)); +printf(" the temperature at point a is %d degF \n",tb(5)); +printf(" the temperature at point a is %d degF \n",tc(5)); +printf(" the temperature at point a is %d degF \n",td(5)); \ No newline at end of file -- cgit