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Heat Transfer Home Work

% Programmer: Aaron Klapheck
% Problem 7.16
% 7-April-2009
clear, clc, home
fprintf('The date and time: %s \n', datestr(now))

The date and time: 08-Apr-2009 19:16:24 

Part b

% Graph the heat removal rate per unit width vs. air velocity.

% Equations to use:

% Reynolds number (R) = (rho).*v.*x./(mu) ... (eqn 1)

% Nusselt number (Nu) = 0.037.*R.^(4/5).*Pr.^(1/3) ... (eqn 2)

% convection cooeficiant (h) = Nu.*kf./(L) ... (eqn 3)

% convective heat transfer (q) = -h.*(Ts-T_inf)*2(L*W)
% rearange to get: q/w = h.*(Ts-T_inf)*2.*L ... (eqn 4)
% Note: heat removeal means no negative sign.

% Given:

Ts = 523; %K
T_inf = 300; %K
Tf = (Ts+T_inf)/2; %K
L = 0.15; %m
Sr = 10; % km/h, Start Range
Er = 100; % km/h, End Range

% Air properties:
rho = 0.8497; %kg/m^3
mu = 234.63e-7; %N*s/m^2
kf = 34.57e-3; %W/(m*K)
Pr = 0.689;

heat removal rate per unit width vs. air velocity

v = [Sr:0.0001:Er];

R = rho.*(v.*1000/3600).*L./(mu);
Nu = 0.037.*R.^(4/5).*Pr.^(1/3);
h = Nu.*kf./(L);
q_per_w = h.*(Ts-T_inf)*2.*L;

plot(v, q_per_w), xlabel('Free Stream Air Velocity, (km/h)'), ...
    ylabel('Heat Removal Rate Per Unit Width (W/m)'), ...
    title('Heat Removal vs. Air Velocity')

Published with MATLAB® 7.5