Hello,
I am trying to solve an equation using Matlab. It is not very difficult as I can solve it with a TI-NspireCX CAS calculator. However when I enter it in Matlab I got an error.> I think I need a different function to solve non linear equations.
I have the constants stated in the end of this question. If I enter the equation eq1 as follows
syms Ueq1=U-(Vp*g*Rhop*dp/(12*nu*Ap*Rhof*(1+0.15*((U*dp/nu)^0.687))))
I get the error
>> solve(eq1,U) Warning: The solutions are parametrized by the symbols: z2 = RootOf(6651387589061087*570373326759099375^(313/1000)*73786976294838206464^(687/1000)*z^1687 + 25291827111579717140695933190137500*z^1000 - 4231294337740989007622062917984000000, z)> In solve at 171
If I enter a simpler equation I get the result
for example
>> eq2=U-(Vp*g*Rhop*dp)/(12*nu*Ap*Rhof);>> solve(eq2,U)ans =5886306028412047/35184372088832
What could be the problem? Thanks very much!
David R
%Variables and constants needed for the equation
dp=2*(10^(-3)); %Droplet diametre m
Ap=pi*(dp^2)/4; %Droplet surface m2
Sp=pi*(dp^2); %surface of heat exchange of particle/droplet m2
nu=15.46*10^-6; %kinematic viscosity@279K
Stow=10*7; %Tower cross section
Airf=600000; %Air flow rate in m3/h
Uf=Airf/Stow/3600; % Air flow speed
Rhop=1400; % Density of particle kg/m3
Rhof=1.18; % Density of air kg/m3@279K
g=9.81; %gravity m/s2
Vp=(4/3)*pi*(dp/2)^3; % volume of particle/droplet m3
Cp=1680; % Specifique heat of particle in J/kg
Tinf=283; %Air flow temperature in Kelvin
T0=443; %Droplet cristalization temperature in Kelvin
Ti=459; %Temperature at nozzle (spray outlet)
L_air=0.025; %Heat conductivity of air W/m'C
Hs=187500; % jules/kg
Best Answer