%************************************************
%* Name: Dip Patel Date: 2/25/15 *
%* File: FluidMechanicsProgram.m *
%* Instructor: DMG 12:40 *
%************************************************
fprintf (‘\n’)
fprintf (‘\n************************************************’)
fprintf (‘\n* Name: Dip Patel Date: 2/25/15 *’)
fprintf (‘\n* File: FluidMechanicsProgram.m *’)
fprintf (‘\n* Instructor: DMG 12:40 *’)
fprintf (‘\n************************************************’)
fprintf (‘\n’)
%Info Section
fprintf (‘Hello. This program will calculate the missing variable of\n’)
fprintf (‘the Volumetric Flow Rate Equation, and will also calculate\n’)
fprintf (‘the average velocity, shear stress at the wall, hydraulic\n’)
fprintf (‘diameter, reynolds number, and entrance length. This program\n’)
fprintf (‘will then plot the velocity and shear stress across the length\n’)
fprintf (‘of the channel.\n’)
fprintf (‘Instructions: Enter value if available, -1 if not.\n’)
%Data Input by User
q = input(‘Volumetric Flow Rate: ‘);
w = input(‘Width: ‘);
h = input(‘Height: ‘);
l = input(‘Length: ‘);
p = input(‘Delta P: ‘);
u = input(‘Viscosity: ‘);
fprintf(‘\n’)
%If else ladder to determine what is missing, and to calculate its value
%and display it to the screen
if q == -1
q = (w*(h^3)*p)/(12*u*l);
fprintf(‘Volumetric Flow Rate: \t%.3f cm^3/s\n’, q)
elseif w == -1
w = (12*u*l*q)/((h^3)*p);
fprintf(‘Width: \t%.3f cm\n’, w)
elseif h == -1
h = ((12*u*l*q)/(w*p))^-3;
fprintf(‘Height: \t%.3f cm\n’, h)
elseif l == -1
l = (w*(h^3)*p)/(12*u*q);
fprintf(‘Length: \t%.3f cm\n’, l)
elseif p == -1
p = (12*u*l*q)/((h^3)*w);
fprintf(‘Delta P: \t%.3f dynes/cm\n’, p)
elseif u == -1
u = (w*(h^3)*p)/(12*l*q);
fprintf(‘Viscosity: \t%.3f g/cm*s\n’, u)
else
end
%calculate supplementary values
Vavg = ((h^2)*p)/(12*u*l);
tau = ((h/2)*p)/l;
Dh = (4*w*h)/((2*w)+(2*h));
Re = (Vavg*Dh)/u;
Le = 0.06*Re*Dh;
%print out all calculated values
fprintf(‘Average Velocity: \t\t%.3f cm/s\n’, Vavg)
fprintf(‘Shear Stress at Wall: \t%.3f dynes/cm^2\n’, tau)
fprintf(‘Hydraulic Diameter: \t%.3f cm\n’, Dh)
fprintf(‘Reynolds Number: \t\t%.3f\n’, Re)
fprintf(‘Entrance Length: \t\t%.3f cm\n’, Le)
%array of different places across the channel, for use later
y = linspace(-h/2,h/2,250);
%use for loop to calculate
for i = 1:1:250
V(i) = (p/8*u*l)*((h^2)-4*((y(i)))^2);
T(i) = (p*abs(y(i)))/l;
end
plot(y,V,’-‘)
xlabel(‘Distance Across Channel (cm)’)
ylabel(‘Velocity (cm/s)’)
title(‘Velocity Across Channel’)
figure
plot(y,T, ‘-‘)
xlabel(‘Distance Across Channel (cm)’)
ylabel(‘Shear Stress (dynes/cm^2)’)
title(‘Shear Stress Across Channel’)