Liquid-Ring Pumps.
Nature and purpose
 	The following URL provides the necessary background information:
	wikipedia
The following images how PHOENICS simulates them quantitatively.
Cyclically-steady blades and water surface
transient water contours, 1
later transient water contours, 2
Specification
	Input:
-  The geometry of the fixed and moving parts of the pump by way of the output from one or more solid-modelling packages of standard format 
 -  the material(s) of which it will be constructed;
 -  the gaseous and liquid materials which will pass through the pumps;
 -  the rotation speed of the impeller;
 -  the pressures and temperatures of the gaseous and liquid materials at their inlets to the pump;
 -  the pressures prevailing at the outlets to the pump for gas and liquid;
 
	Output:
-  What will be the time-average torque which must be applied to the impeller shaft;
 -  What will be the time-average distribution of liquid concentration, gas concentration, pressure, temperature and velocity components within the pump [‘distribution’ means ‘values prevailing at all positions in three-dimensional space].
 -  qualitative understanding of the processes which occur in the pump by visual observation of three-dimensional transient representations on the computer screen.