%function [V,Vmax,Vmean,Q] = ViscousFlow (Pa,Pb,R,mu,l)

This program simulates the velocity profile across the radius of the tube with the following
inputs
Pa : Pressure in point a in Pascal .
Pb : Pressure in the other extremity b
in Pascal.
mu : Viscosity of the fluid in
Pascal.second
R : Radius of the tube in meter.
l : length of the tube in meter.

We assume that the environment is ambient(AT=298.15 K) and the viscosity
is static .

The outputs of the program are :

Vmax: Maximum velocity in m/s.
Vmea: Mean Velocity in the whole tube in
m/s.
Q : Volumic flow in meter^3 /second .

The Unit of the viscosity is also: Kg.second^-1.meter^-1.

The table below gives some numerical values of various fluids in ambient Temperature[1] :
Liquid ||Viscosity (Pas.s)

water :8.94e-4.
olive oil :0.081.
mercury :1.526e-3.
ethanol :1.074e-3.
castor oil :0.985.
propanol :1.945e-3.
pitch :2.3e+8.
motor oil :0.065.
ketchup :50-100.
honey :2-10.
Blood(37°) :(3-4)e-3.

Some of the materials above have variable viscosity.
References :
-----------
[1]: http://en.wikipedia.org/wiki/Viscosity#cite_note-23.
[2]: Viscosity of liquids and Gazs :
http://hyperphysics.phy-astr.gsu.edu/Hbase/tables/viscosity.html.