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 --- 1309/CH7/EX7.1/Figure7_1.jpeg | Bin 0 -> 37722 bytes 1309/CH7/EX7.1/Result7_1.pdf | Bin 0 -> 94313 bytes 1309/CH7/EX7.1/ch7_1.sce | 64 +++++++++++++++++++++++++++++++++++++++++ 1309/CH7/EX7.10/Result7_10.pdf | Bin 0 -> 94141 bytes 1309/CH7/EX7.10/ch7_10.sce | 52 +++++++++++++++++++++++++++++++++ 1309/CH7/EX7.2/Figure7_2.jpeg | Bin 0 -> 47805 bytes 1309/CH7/EX7.2/Result7_2.pdf | Bin 0 -> 95030 bytes 1309/CH7/EX7.2/ch7_2.sce | 52 +++++++++++++++++++++++++++++++++ 1309/CH7/EX7.3/Result7_3.pdf | Bin 0 -> 93091 bytes 1309/CH7/EX7.3/ch7_3.sce | 27 +++++++++++++++++ 1309/CH7/EX7.4/Result7_4.pdf | Bin 0 -> 91897 bytes 1309/CH7/EX7.4/ch7_4.sce | 21 ++++++++++++++ 1309/CH7/EX7.5/Result7_5.pdf | Bin 0 -> 92060 bytes 1309/CH7/EX7.5/ch7_5.sce | 25 ++++++++++++++++ 1309/CH7/EX7.6/Result7_6.pdf | Bin 0 -> 90134 bytes 1309/CH7/EX7.6/ch7_6.sce | 17 +++++++++++ 1309/CH7/EX7.7/Result7_7.pdf | Bin 0 -> 93095 bytes 1309/CH7/EX7.7/ch7_7.sce | 42 +++++++++++++++++++++++++++ 1309/CH7/EX7.8/Result7_8.pdf | Bin 0 -> 92432 bytes 1309/CH7/EX7.8/ch7_8.sce | 30 +++++++++++++++++++ 1309/CH7/EX7.9/Result7_9.pdf | Bin 0 -> 91625 bytes 1309/CH7/EX7.9/ch7_9.sce | 30 +++++++++++++++++++ 22 files changed, 360 insertions(+) create mode 100755 1309/CH7/EX7.1/Figure7_1.jpeg create mode 100755 1309/CH7/EX7.1/Result7_1.pdf create mode 100755 1309/CH7/EX7.1/ch7_1.sce create mode 100755 1309/CH7/EX7.10/Result7_10.pdf create mode 100755 1309/CH7/EX7.10/ch7_10.sce create mode 100755 1309/CH7/EX7.2/Figure7_2.jpeg create mode 100755 1309/CH7/EX7.2/Result7_2.pdf create mode 100755 1309/CH7/EX7.2/ch7_2.sce create mode 100755 1309/CH7/EX7.3/Result7_3.pdf create mode 100755 1309/CH7/EX7.3/ch7_3.sce create mode 100755 1309/CH7/EX7.4/Result7_4.pdf create mode 100755 1309/CH7/EX7.4/ch7_4.sce create mode 100755 1309/CH7/EX7.5/Result7_5.pdf create mode 100755 1309/CH7/EX7.5/ch7_5.sce create mode 100755 1309/CH7/EX7.6/Result7_6.pdf create mode 100755 1309/CH7/EX7.6/ch7_6.sce create mode 100755 1309/CH7/EX7.7/Result7_7.pdf create mode 100755 1309/CH7/EX7.7/ch7_7.sce create mode 100755 1309/CH7/EX7.8/Result7_8.pdf create mode 100755 1309/CH7/EX7.8/ch7_8.sce create mode 100755 1309/CH7/EX7.9/Result7_9.pdf create mode 100755 1309/CH7/EX7.9/ch7_9.sce (limited to '1309/CH7') diff --git a/1309/CH7/EX7.1/Figure7_1.jpeg b/1309/CH7/EX7.1/Figure7_1.jpeg new file mode 100755 index 000000000..1fd5736f2 Binary files /dev/null and b/1309/CH7/EX7.1/Figure7_1.jpeg differ diff --git a/1309/CH7/EX7.1/Result7_1.pdf b/1309/CH7/EX7.1/Result7_1.pdf new file mode 100755 index 000000000..6ce8becb5 Binary files /dev/null and b/1309/CH7/EX7.1/Result7_1.pdf differ diff --git a/1309/CH7/EX7.1/ch7_1.sce b/1309/CH7/EX7.1/ch7_1.sce new file mode 100755 index 000000000..e82146a44 --- /dev/null +++ b/1309/CH7/EX7.1/ch7_1.sce @@ -0,0 +1,64 @@ +clc; +clear; +printf("\t\t\tChapter7_example1\n\n\n"); +printf("\t\t\tSolution to part (a)\n"); +// determination of boundary layer growth with length +// properties of air at 27 degree celsius from appendix table D.1 +rou=1.177; // density in kg/cu.m +v=15.68e-6; // viscosity in sq.m/s +L=0.5; // length in m +V_inf=1; // air velocity in m/s +Re= (V_inf*L)/v; // Reynolds Number +printf("The Reynolds Number is %.2e ",Re); +// Reynolds Number is less than 5e5 hence the flow is laminar and Blasius Solution applies +x=[0 0.125 0.25 0.375 0.5]; // distances in m where boundary layer growth is determined +[n,m]=size(x); +for i=1:m + delta(i)=5*x(i)^0.5/(V_inf/v)^0.5; +end +subplot(211); +plot(x,delta); +a=gca(); +newTicks=a.x_ticks; +newTicks(2)=[0;0.125;0.25;0.375;0.5]; +newTicks(3)=['0';'0.125';'0.25';'0.375';'0.50']; +a.x_ticks=newTicks; +title('Boundary-layer growth with distance'); +xlabel('x, m'); +ylabel('delta, m^(1/2)'); +printf("\n\t\t\tSolution to part (b)\n"); +// produce graph of velocity distribution at x=0.25 m +eta=0:5; +[p,q]=size(eta); +f=[0 0.32979 0.62977 0.84605 0.95552 0.99155];//value for f for corresponding eta value from Table 7.1 +for j=1:q + y(j)=eta(j)*(v*0.25)^0.5; +end +printf("\n\t\t\tResults of Calculations for Example 7.1\n"); +printf("\teta\t\ty,m\t\t\tf=vx, m/s\n"); +for i=1:q +printf("\t%d\t\t%.2e\t\t%.5f\n",eta(i),y(i),f(i)); +end +subplot(212); +plot(f,y); +b=gca(); +newTicks1=b.x_ticks; +newTicks1(2)=[0;0.25;0.5;0.75;1.0]; +newTicks1(3)=['0';'0.25';'0.5';'0.75';'1.0']; +b.x_ticks=newTicks1; +newTicks2=b.y_ticks; +newTicks2(2)=[0;0.0025;0.005;0.0075;0.010]; +newTicks2(3)=['0';'0.0025';'0.005';'0.0075';'0.010']; +b.y_ticks=newTicks2; +title('Velocity Distribution at x=0.25 m'); +xlabel('Vx, m/s'); +ylabel('y, m'); +printf("\t\t\tSolution to part (c)\n"); +// calculation of absolute viscosity +gc=1; +mu=rou*v/gc; +printf("\nThe absolute viscosity is %.3e N.s/sq.m",mu); +b=1; // width in m +Df=0.664*V_inf*mu*b*(Re)^0.5; +printf("\nThe skin-drag is %.2e N",Df); +printf("\nThe skin-drag including both sides of plate is %.2e N",2*Df); diff --git a/1309/CH7/EX7.10/Result7_10.pdf b/1309/CH7/EX7.10/Result7_10.pdf new file mode 100755 index 000000000..dd875dd62 Binary files /dev/null and b/1309/CH7/EX7.10/Result7_10.pdf differ diff --git a/1309/CH7/EX7.10/ch7_10.sce b/1309/CH7/EX7.10/ch7_10.sce new file mode 100755 index 000000000..438f14e50 --- /dev/null +++ b/1309/CH7/EX7.10/ch7_10.sce @@ -0,0 +1,52 @@ +clc; +clear; +printf("\t\t\tChapter7_example10\n\n\n"); +// Calculation of the pressure drop for the air passing over the tubes and the heat transferred to the air. +// properties of air at 70 + 460 = 530 degree R = 540 degree R from appendix table D1 +rou= 0.0735; // density in Ibm/cu.ft +cp=0.240; // specific heat BTU/(lbm-degree Rankine) +v= 16.88e-5; // viscosity in sq.ft/s +kf = 0.01516 ; // thermal conductivity in BTU/(hr.ft.degree Rankine) +a = 0.859; // diffusivity in sq.ft/hr +Pr = 0.708; // Prandtl Number +// specifications of 3/4 standard type K copper tubing from appendix table F2 +OD=0.875/12; // outer diameter in ft +ID=0.06208; // inner diameter in ft +A=0.003027; // cross sectional area in sq.ft +L=2; +sL=1.5/12; +sT=1.3/12; +V_inf=12; // velocity of air in ft/s +V1=(sT*V_inf)/(sT-OD); // velocity at area A1 in ft/s +printf("\nVelocity at area A1 is %.1f ft/s",V1); +sD=((sL)^2+(sT/2)^2)^0.5; // diagonal pitch in inch +printf("\nThe diagonal pitch is %.2f in",sD*12); +V2=(sT*V_inf)/(2*(sD-OD)); +printf("\nVelocity at area A2 is %.1f ft/s",V2); +if V1>V2 then + Vmax=V1; + else Vmax=V2; +end +Re_D=Vmax*OD/v; // Reynolds Number +printf("\nThe Reynolds number is %.2e ",Re_D); +sT_OD=1.3/0.875; +sT_sL=1.3/1.5; +printf("\nThe values of parameters are sT/Do=%.2f and sT/sL=%.2f",sT_OD,sT_sL); +f1=0.35; //value of f1 for above values of sT/Do and Re +f2=1.05; //Corresponding value of f2 for above values of sT/sL and Re +gc=32.2; +N=7; +dP=N*f1*f2*(rou*Vmax^2/(2*gc)); +printf("\nThe pressure drop is %.2f lbf/ft^2 = %.4f psi",dP, dP/147); +sL_Do=sL/OD; +C1=0.438; //value of C1 for above values of sT/Do and sL/Do +C2=0.97; //value of C2 for above values of sT/Do and sL/Do +m=0.565; //value of m for above values of sT/Do and sL/Do +hc=kf*1.13*C1*C2*(Re_D)^m*(Pr)^(1/3)/OD; // The convection coefficient +printf("\nThe convection coefficient is %.1f BTU/(hr.sq.ft.degree Rankine)",hc); +As=70*%pi*OD*L; // outside surface area of 70 tubes +printf("\nThe outside surface area of 70 tubes is %.1f sq.ft",As); +Tw=200; // outside surface temeperature in degree F +T_inf=70; // air temperature in degree F +q=hc*As*(Tw-T_inf);// heat transferred +printf("\nThe heat transferred is %.2e BTU/hr",q); diff --git a/1309/CH7/EX7.2/Figure7_2.jpeg b/1309/CH7/EX7.2/Figure7_2.jpeg new file mode 100755 index 000000000..561b2a3c4 Binary files /dev/null and b/1309/CH7/EX7.2/Figure7_2.jpeg differ diff --git a/1309/CH7/EX7.2/Result7_2.pdf b/1309/CH7/EX7.2/Result7_2.pdf new file mode 100755 index 000000000..dd7f5ef0f Binary files /dev/null and b/1309/CH7/EX7.2/Result7_2.pdf differ diff --git a/1309/CH7/EX7.2/ch7_2.sce b/1309/CH7/EX7.2/ch7_2.sce new file mode 100755 index 000000000..9dc973828 --- /dev/null +++ b/1309/CH7/EX7.2/ch7_2.sce @@ -0,0 +1,52 @@ +clc; +clear; +printf("\t\t\tChapter7_example2\n\n\n"); +// determination of temperature profile +// properties of water at (40 + 100)/2 = 70°F = 68°F from appendix table C11 +rou= 62.4; // density in Ibm/ft^3 +cp=0.9988; // specific heat BTU/(lbm-degree Rankine) +v= 1.083e-5; // viscosity in sq.ft/s +kf = 0.345 ; // thermal conductivity in BTU/(hr.ft.degree Rankine) +a = 5.54e-3; // diffusivity in sq.ft/hr +Pr = 7.02; // Prandtl Number +V=1.2; // velocity in ft/s +x=[1 2]; // distances from plate entry in ft +for i=1:2 +Re(i)=(V*x(i))/v; // Reynolds Number at x=1 ft +printf("\nThe Reynolds Number at x=%d ft is %.3e",i,Re(i)); +// since Reynolds Number is less than 5*10^5, the flow is laminar +hL(i)=0.664*Pr^(1/3)*Re(i)^0.5*kf/x(i); +printf("\nThe average convection coefficient at x=%d is %.1f BTU/(hr. sq.ft. degree Rankine)",i,hL(i)); +Tw=100; // temperature of metal plate in degree fahrenheit +T_inf=40; // temperature of water in degree fahrenheit +A(i)=x(i)*18/12; // cross sectional area for 1 ft length +q(i)=hL(i)*A(i)*(Tw-T_inf); +printf("\nThe heat transferred to water over the x=%d ft is %.3e BTU/hr",i,q(i)); +end +eta=0:0.2:1.2; +[n m]=size(eta); +theta=[1 .75 .51 .31 .17 .08 0.01]; // values of dimensionless temperature from figure 7.7 corresponding to eta value taken +for i=1:m +y(i)=eta(i)*(v*x(1)/V(1))^0.5; +T(i)=theta(i)*(Tw-T_inf)+T_inf; +end +printf("\nSolution Chart for example 7.2\n"); +printf("\teta\t\ttheta\t\ty, ft\t\t\tT, degree F\n"); +for i=1:m +printf("\t%.1f\t\t%.2f\t\t%.1e\t\t\t%.1f\n",eta(i),theta(i),y(i),T(i)); +end +plot(T,y); +a=gca(); +newTicks=a.x_ticks; +newTicks(2)=[100; 90; 80; 70; 60;50; 40]; +newTicks(3)=['100'; '90'; '80'; '70'; '60';'50'; '40']; +a.x_ticks=newTicks; +newTicks1=a.y_ticks; +newTicks1(2)=[0; 0.001; 0.002; 0.003; 0.004]; +newTicks1(3)=['0'; '0.001'; '0.002'; '0.003'; '0.004']; +a.y_ticks=newTicks1; +a.axes_reverse=["on","off"]; +xgrid(1); +title('Temperature variation (at x = 1 ft) within the boundary layer for the water'); +xlabel('T, degree Fahrenheit'); +ylabel('y, ft'); diff --git a/1309/CH7/EX7.3/Result7_3.pdf b/1309/CH7/EX7.3/Result7_3.pdf new file mode 100755 index 000000000..5736cec8d Binary files /dev/null and b/1309/CH7/EX7.3/Result7_3.pdf differ diff --git a/1309/CH7/EX7.3/ch7_3.sce b/1309/CH7/EX7.3/ch7_3.sce new file mode 100755 index 000000000..a6a759a5b --- /dev/null +++ b/1309/CH7/EX7.3/ch7_3.sce @@ -0,0 +1,27 @@ +clc; +clear; +printf("\t\t\tChapter7_example3\n\n\n"); +// Determination of the average convection coefficient and the total drag force exerted on the plate. +// properties of air at (300 + 400)/2 = 350 K from appendix table D1 +rou= 0.998; // density in kg/cu.m +cp= 1009; // specific heat in J/(kg*K) +v= 20.76e-6; // viscosity in sq.m/s +Pr = 0.697; // Prandtl Number +k= 0.03003; // thermal conductivity in W/(m.K) +a = 0.2983e-4; // diffusivity in sq.m/s +L=1; // Length of plate in m +V=5; // velocity of air in m/s +b=0.5; // width in m +Re=V*L/v; // Reynolds number at plate end +printf("\nThe Reynolds number is %.2e",Re); +// Since the flow is laminar at plate end, The average convection coefficient is calculated with Equation Nu=h*L/k= 0.664 Re^(1/2)Pr^(1/3) +h=k*0.664*Re^(1/2)*Pr^(1/3)/L; // The average convection coefficient in W/(sq.m.K) +printf("\nThe average convection coefficient is %.2f W/(sq.m.K)",h); +Df=0.664*V*rou*v*b*(Re)^0.5; // drag force in N +printf("\nThe drag force is %.2e N",Df); +hx=(1/2)*h; // local convective coefficient +printf("\nThe local convective coefficient is %.2f W/(sq.m.K)",hx); +delta=5*L/(Re)^0.5; // The boundary-layer thickness at plate end +printf("\nThe boundary-layer thickness at plate end is %.2f cm",delta*100); +delta_t=delta/(Pr)^(1/3); +printf("\nThe thermal-boundary-layer thickness is %.2f cm",delta_t*100); diff --git a/1309/CH7/EX7.4/Result7_4.pdf b/1309/CH7/EX7.4/Result7_4.pdf new file mode 100755 index 000000000..41b03e603 Binary files /dev/null and b/1309/CH7/EX7.4/Result7_4.pdf differ diff --git a/1309/CH7/EX7.4/ch7_4.sce b/1309/CH7/EX7.4/ch7_4.sce new file mode 100755 index 000000000..62f2e98f5 --- /dev/null +++ b/1309/CH7/EX7.4/ch7_4.sce @@ -0,0 +1,21 @@ +clc; +clear; +printf("\t\t\tChapter7_example4\n\n\n"); +// Determination of the maximum heater-surface temperature for given conditions +// fluid properties at (300 degree R + 800 degree R)/2 = 550 degree R=540degree R from Appendix Table D.6 +rou= 0.0812; // density in Ibm/ft^3 +cp=0.2918; // specific heat BTU/(lbm-degree Rankine) +v= 17.07e-5; // viscosity in ft^2/s +kf = 0.01546 ; // thermal conductivity in BTU/(hr.ft.degree Rankine) +a = 0.8862; // diffusivity in ft^2/hr +Pr = 0.709; // Prandtl Number +qw=10/(1.5*10.125)*(1/.2918)*144; // The wall flux +printf("\nThe wall flux is %d BTU/(hr. sq.ft)",qw); +V_inf=20; // velocity in ft/s +L=1.5/12; // length in ft +Re_L=V_inf*10*L/v; // Reynolds number at plate end +printf("\nThe Reynolds number at plate end is %.2e",Re_L); +// So the flow is laminar and we can find the wall temperature at plate end as follows +T_inf=300; // free stream temperature in degree Rankine +Tw=T_inf+(qw*L*10/(kf*0.453*(Re_L)^0.5*(Pr)^(1/3))); +printf("\nThe maximum heater surface temperature is %d degree Rankine",Tw); diff --git a/1309/CH7/EX7.5/Result7_5.pdf b/1309/CH7/EX7.5/Result7_5.pdf new file mode 100755 index 000000000..bcb325e28 Binary files /dev/null and b/1309/CH7/EX7.5/Result7_5.pdf differ diff --git a/1309/CH7/EX7.5/ch7_5.sce b/1309/CH7/EX7.5/ch7_5.sce new file mode 100755 index 000000000..1b68cdd89 --- /dev/null +++ b/1309/CH7/EX7.5/ch7_5.sce @@ -0,0 +1,25 @@ +clc; +clear; +printf("\t\t\tChapter7_example5\n\n\n"); +// validation of the equation st.(Pr)^(2/3)=Cd/2 where St: Stanton Number Pr:Prandtl Number Cd: Drag Coefficient +// values of parameters from example 7.4 +rou= 0.0812; // density in Ibm/ft^3 +cp=0.2918; // specific heat BTU/(lbm-degree Rankine) +v= 17.07e-5; // viscosity in ft^2/s +kf = 0.01546 ; // thermal conductivity in BTU/(hr.ft.degree Rankine) +a = 0.8862; // diffusivity in ft^2/hr +Pr = 0.709; // Prandtl Number +Tw=469; // maximum heater temperature in degree Rankine +T_inf=300; // free-stream temperature in degree Rankine +qw=324; // The wall flux in BTU/(hr.ft^2) +V_inf=20; // velocity in ft/s +hx=qw/(Tw-T_inf); // The convection coefficient +printf("\nThe convection coefficient is %.2f BTU/(hr.sq.ft.degree R)",hx); +LHS=(hx/3600)*(Pr)^(2/3)/(rou*cp*V_inf); +printf("\nThe value of left hand side of the equation is %.2e",LHS); +Re_L=1.46e+005; // Reynolds number at plate end +RHS=0.332*(Re_L)^(-0.5); +printf("\nThe value of left hand side of the equation is %.2e",RHS); +err=(LHS-RHS)*100/LHS; +printf("\nThe error is %d percent",err); +printf("\nSince the error is only %d percent, the agreement is quite good",err); diff --git a/1309/CH7/EX7.6/Result7_6.pdf b/1309/CH7/EX7.6/Result7_6.pdf new file mode 100755 index 000000000..75f95318b Binary files /dev/null and b/1309/CH7/EX7.6/Result7_6.pdf differ diff --git a/1309/CH7/EX7.6/ch7_6.sce b/1309/CH7/EX7.6/ch7_6.sce new file mode 100755 index 000000000..0be0224fd --- /dev/null +++ b/1309/CH7/EX7.6/ch7_6.sce @@ -0,0 +1,17 @@ +clc; +clear; +printf("\t\t\tChapter7_example6\n\n\n"); +// Estimation of the drag due to skin friction +// properties of water at 68°F from Appendix Table C.11 +rou= 62.4; // density in Ibm/cu.ft +v= 1.083e-5; // viscosity in sq.ft/s +V_inf=5*.5144/.3048; // barge velocity in ft/s using conversion factors from appendix table A1 +printf("\nThe barge velocity is %.2f ft/s",V_inf); +L=20; // Length of barge in ft +Re_L=V_inf*L/v; // Reynolds number at plate end +printf("\nThe Reynolds number at plate end is %.2e",Re_L); +Cd=0.003; //value of Cd corresponding to the Reynolds number from figure 7.11 +gc=32.2; +b=12; // width in ft +Df=(Cd*rou*V_inf^2*b*L)/(2*gc); +printf("\nThe drag force is %d lbf",Df); diff --git a/1309/CH7/EX7.7/Result7_7.pdf b/1309/CH7/EX7.7/Result7_7.pdf new file mode 100755 index 000000000..5eb3546c4 Binary files /dev/null and b/1309/CH7/EX7.7/Result7_7.pdf differ diff --git a/1309/CH7/EX7.7/ch7_7.sce b/1309/CH7/EX7.7/ch7_7.sce new file mode 100755 index 000000000..22a800526 --- /dev/null +++ b/1309/CH7/EX7.7/ch7_7.sce @@ -0,0 +1,42 @@ +clc; +clear; +printf("\t\t\tChapter7_example7\n\n\n"); +// Determination of wattage requirement +// properties of carbon dioxide at a film temperature of (400+600)/2 = 500 K from appendix table D2 +rou= 1.0732; // density in kg/m^3 +cp= 1013; // specific heat in J/(kg*K) +v= 21.67e-6; // viscosity in m^2/s +Pr = 0.702; // Prandtl Number +k= 0.03352; // thermal conductivity in W/(m.K) +a = 0.3084e-4; // diffusivity in m^2/s +V_inf=60; // carbon dioxide velocity in m/s +x_cr=(5e5)*v/V_inf; // The transition length in m +printf("\nThe transition length is %.1f cm",x_cr*100); +w=4; // width of each heater in cm +b=.16; // effective heating length in m +Tw=600; // temperature of heater surface in K +T_inf=400; // temperature of carbon dioxide in K +r=pmodulo(x_cr*100,w); +n=(x_cr*100+r)/w; // number of heater where transition occurs +printf("\nThe transition thus occur at %dth heater",n); +m=6; // number of heater strips +q=zeros(m+1,1); +x=[0.04 0.08 0.12 0.16 0.20 0.24]; +for i=1:n-1 // transition occurs at 5th heater, so laminar zone equation is followed till then + h(i)=(0.664*k)*(V_inf/v)^0.5*(Pr)^(1/3)/x(i)^0.5; + printf("\n\nThe convective coefficient for heater no. %d is %d W/(sq.m.K)",i,h(i)); + q(i+1)=h(i)*x(i)*b*(Tw-T_inf); + dq(i)=q(i+1)-q(i); + printf("\nThe heat transferred by heater no. %d is %d W",i,dq(i)); +end +// Turbulent zone exists from 5th heater onwards so the following equation is followed Nu=h*x/kf=[0.0359*(Re_L)^(4/5)-830]*(Pr)^(1/3) +for i=5:6 + Re_L(i)=V_inf*x(i)/v; + h(i)=(k/x(i))*[0.0359*(Re_L(i))^(4/5)-830]*(Pr)^(1/3) + printf("\n\nThe Reynolds number for heater no. %d is %.2e",i,Re_L(i)); + printf("\nThe convective coefficient for heater no. %d is %.1f W/(sq.m.K)",i,h(i)); + q(i+1)=h(i)*x(i)*b*(Tw-T_inf); + dq(i)=q(i+1)-q(i); + printf("\nThe heat transferred by heater no. %d is %d W",i,dq(i)); +end + diff --git a/1309/CH7/EX7.8/Result7_8.pdf b/1309/CH7/EX7.8/Result7_8.pdf new file mode 100755 index 000000000..ce33b8313 Binary files /dev/null and b/1309/CH7/EX7.8/Result7_8.pdf differ diff --git a/1309/CH7/EX7.8/ch7_8.sce b/1309/CH7/EX7.8/ch7_8.sce new file mode 100755 index 000000000..ca71853dd --- /dev/null +++ b/1309/CH7/EX7.8/ch7_8.sce @@ -0,0 +1,30 @@ +clc; +clear; +printf("\t\t\tChapter7_example8\n\n\n"); +// Estimation of force exerted on the pole +// properties of air at given conditions from appendix table D1 +rou= 0.0735; // density in Ibm/ft^3 +v= 16.88e-5; // viscosity in ft^2/s +V=20*5280/3600; // flow velocity in ft/s +printf("\nThe flow velocity is %.1f ft/s",V); +D=12/12; // diameter of pole in ft +L=30;// length of pole in ft +gc=32.2; +Re_D=V*D/v; // Reynolds Number for flow past the pole +printf("\nThe Reynolds Number for flow past the pole is %.2e ",Re_D); +Cd_cylinder=1.1; // value of Cd for smooth cylinder from figure 7.22 +A_cylinder=D*L; // frontal area of pole +printf("\nThe frontal area of pole is %d sq.ft",A_cylinder); +Df_cylinder=Cd_cylinder*(1/2)*rou*V^2*A_cylinder/gc; +printf("\nThe Drag force exerted on only the pole is %.1f lbf",Df_cylinder); +D_square=2/12; // length of square part of pole +L_square=4; +Re_square=V*D_square/v; // Reynolds Number for square part of pole +printf("\nThe Reynolds Number for square part of pole is %.1e",Re_square); +Cd_square=2; // Corresponding value of Cd for square part from figure 7.23 +A_square=D_square*L_square; // projected frontal area of square part +printf("\nThe frontal area of square part of pole is %.3f sq.ft",A_square); +Df_square=Cd_square*(1/2)*rou*V^2*A_square/gc; +printf("\nThe Drag force exerted on cross piece of the pole is %.2f lbf",Df_square); +Df_total=Df_cylinder+Df_square; +printf("\nThe total drag force on the pole is %.1f lbf",Df_total); diff --git a/1309/CH7/EX7.9/Result7_9.pdf b/1309/CH7/EX7.9/Result7_9.pdf new file mode 100755 index 000000000..05273af03 Binary files /dev/null and b/1309/CH7/EX7.9/Result7_9.pdf differ diff --git a/1309/CH7/EX7.9/ch7_9.sce b/1309/CH7/EX7.9/ch7_9.sce new file mode 100755 index 000000000..0c440c728 --- /dev/null +++ b/1309/CH7/EX7.9/ch7_9.sce @@ -0,0 +1,30 @@ +clc; +clear; +printf("\t\t\tChapter7_example9\n\n\n"); +// determination of required current +// properties of air at film temperature (300 + 500)/2 = 400 K from appendix table D1 +rou= 0.883; // density in kg/cu.m +cp= 1014; // specific heat in J/(kg*K) +v= 25.90e-6; // viscosity in sq.m/s +Pr = 0.689; // Prandtl Number +kf= 0.03365; // thermal conductivity in W/(m.K) +a = 0.376e-4; // diffusivity in sq.m/s +V_inf=1; // velocity in m/s +D=0.00013; // diameter in m +L=1/100; // length of wire in cm +Re_D=V_inf*D/v; // The Reynolds number of flow past the wire +printf("\nThe Reynolds number of flow past the wire is %.3f",Re_D); +C=0.911; //value of C for cylinder from table 7.4 +m=0.385; //value of m for cylinder from table 7.4 +hc=kf*C*(Re_D)^m*(Pr)^(1/3)/D; // the convection coefficient in W/(m^2.K) +printf("\nThe convection coefficient is %d W/(sq.m.K)",hc); +Tw=500; // air stream temperature in K +T_inf=300; // wire surface temperature in K +As=%pi*D*L; // cross sectional area in sq.m +qw=hc*As*(Tw-T_inf); // The heat transferred to the air from the wire +printf("\nThe heat transferred to the air from the wire is %.3f W",qw); +resistivity=17e-6; // resistivity in ohm cm +Resistance=resistivity*(L/(%pi*D^2)); // resistance in ohm +printf("\nThe resistance is %.3f ohm",Resistance/100); +i=(qw*100/Resistance)^0.5; // current in ampere +printf("\nThe current is %.1f A",i); -- cgit