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 --- 905/CH2/EX2.4/2_4.sce | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100755 905/CH2/EX2.4/2_4.sce (limited to '905/CH2/EX2.4/2_4.sce') diff --git a/905/CH2/EX2.4/2_4.sce b/905/CH2/EX2.4/2_4.sce new file mode 100755 index 000000000..301a4dd31 --- /dev/null +++ b/905/CH2/EX2.4/2_4.sce @@ -0,0 +1,62 @@ +clear; +clc; + +// Illustration 2.4 +// Page: 99 + +printf('Illustration 2.4 - Page: 99\n\n'); + +// solution +// Mass Transfer into a Dilute Stream Flowing Under Forced Convection in a Circular Conduit + +n = 6; // [number of variables] +// Variables Symbols Dimensions +// Tube diameter D L +// Fluid density row M/L^3 +// Fluid viscosity u M/(Lt) +// Fluid velocity v L/t +// Mass diffusivity D_AB L^2/t +// Mass-transfer coefficient kc L/t + +// To determine the number of dimensionless parameters to be formed, we must know the rank, r, of the dimensional matrix. +// The dimensional matrix is +DM = [0,0,1,1,0,0;1,1,-3,-1,2,1;-1,-1,0,0,-1,-1]; +[E,Q,Z ,stair ,rk]=ereduc(DM,1.d-15); +printf("Rank of matrix is %f\n\n",rk); + +//The numbers in the table represent the exponent of M, L, and t in the dimensional expression of each of the six variables involved. For example, the dimensional expression of p is M/Lt; hence the exponents are 1, -1, and -1 + +// From equation 2.16 +i = n-rk; // [number of dimensional groups] +// Let the dimensional groups are pi1, pi2 and pi3 +// Therefore pi1 = (D_AB)^a*(row)^b*(D)^c*kc +// pi2 = (D_AB)^d*(row)^e*(D)^f*v +// pi3 = (D_AB)^g*(row)^h*(D)^i*u + +// Solving for pi1 +// M^0*L^0*t^0 = 1 = (L^2/t)^a*(M/L^3)^b*(L)^c*(L/t) + +// Solution of simultaneous equation +function[f]=F(e) + f(1) = 2*e(1)-3*e(2)+e(3)+1; + f(2) = -e(1)-1; + f(3) = -e(2); + funcprot(0); +endfunction + +// Initial guess: +e = [0.1 0.8 0.5]; +y = fsolve(e,F); +a = y(1); +b = y(2); +c = y(3); +printf("The coefficients of pi1 are %f %f %f\n\n",a,b,c); +// Similarly the coefficients of pi2 and pi3 are calculated +// Therefore we get pi1 = kc*D/D_AB = Sh i.e. Sherwood Number +// pi2 = v*D/D_AB = P_ed i.e. Peclet Number +// pi3 = u/(row*D_AB) = Sc i.e. Schmidt Number + +// Dividing pi2 by pi3 gives +// pi2/pi3 = D*v*row/u = Re i.e. Renoylds number + +printf('The result of the dimensional analysis of forced-convection mass transfer in a circular conduit indicates that a correlating relation could be of the form\n Sh = function(Re,Sc)\n which is analogous to the heat transfer correlation \n Nu = function(Re,Pr)'); \ No newline at end of file -- cgit