Modeling (Motor & Fan) in Spice?

Has anybody come across Spice models for a motor-driven blower or fan?
 I have models for small motors, wher (to a first approximation) motor
speed is proportional to terminal voltage and shaft torque is
proportional to armature current.  But I have a data sheet for a
blower, with a performance curve relating air flow rate (cu ft/min) to
back pressure (inches of H2O).  I can easily measure terminal
charcteristics (voltage and current) with the air path either
completely open or fully blocked.  Now - how do I couple this
information together to relate the electrical characteristics to a
given flow/pressure situation?

Thanks - 
Dale