JakobCHR.com
 
Quick Navigation:
 
Personal:
 Go to Home
 MS Research
 PhD Research
 Curriculum Vitae

General:
 Linux

Soon to come:
 Matlab
 On-line Stores
 Cycling
 Medicine & Health
 LaTeX
 OOP & C++
 Sony PCM-R500 DAT


next up previous contents index
Next: Viscosity of steam at Up: Derivation of curve fits Previous: Surface tension   Contents   Index


Viscosity of water at saturation

According to [28, p. 35]B2 the viscosity of liquids may be fit accurately to a model function of the form

\begin{displaymath}
\mu(t) = \mu_0 \exp\left[ a + b \left(\frac{T}{T_0}\right) + c
\left(\frac{T}{T_0}\right)^2 \right]
\end{displaymath} (B2)

where $(\mu_0,T_0)$ is a reference point and $a,b,c \in \Re$.

If we transform our data such that


\begin{eqnarray*}
\mu_i &\mapsto& \mu_i^* \;\hbox{$=$\kern-0.68em\raise1.1ex
\...
...e1.1ex
\hbox{$\scriptscriptstyle\triangle$}}\;\frac{T_i}{T_0}
\end{eqnarray*}


$\textstyle \parbox{1.50cm}{\begin{eqnarray}
\end{eqnarray}}$

we actually have to fit the transformed data points $(\mu_i^*,T_i^*)$ to the quadratic model function

m(t) = a + bT* + c(T*)2 (B3)

If we fit data in the temperature interval 230 ${}^\circ\mbox{C}$ to 300 ${}^\circ\mbox{C}$ given by [25, Table 6, Db 5] in a least square sense to the model function we obtain the following coefficients


\begin{eqnarray*}
a &=& 1.220692035 \\
b &=& -1.306580184 \\
c &=& 8.525375...
...& (97.4\cdot 10^{-5} {\mbox{P}}, 270\mbox{${}^\circ\mbox{C}$})
\end{eqnarray*}


$\textstyle \parbox{1.50cm}{\begin{eqnarray}
\end{eqnarray}}$

The resulting fit has an error less than 0.13 percent in the temperature range [230 ${}^\circ\mbox{C}$;300 ${}^\circ\mbox{C}$].

In the figures B.3 and B.4 we see the a comparison of the fit and the data and the error of the fit as a function of temperature respectively.

\begin{figure}
% latex2html id marker 47005\rule{\textwidth}{0.2mm}
\rule{0cm}...
...\mu_f(t)$(\raise0.5ex\hbox{$.....$}) and the data points ($\cdot$).}\end{figure}

\begin{figure}
% latex2html id marker 47025\rule{\textwidth}{0.2mm}
\rule{0cm}...
...rve fit formula of the viscosity of water at
saturation $\mu_f(t)$.}\end{figure}


next up previous contents index
Next: Viscosity of steam at Up: Derivation of curve fits Previous: Surface tension   Contents   Index  
 
 
 
Revision 2.0, Copyright © 1999-2004 Jakob Christensen
http://www.JakobCHR.com
E-Mail: webmaster@JakobCHR.com
Top Quality
Developed with

Danish
Brain Power
Linux Powered!