- Non-Inertia-Feedback-Thermofluidic-Engine (NIFTE)
let me report on a new thermodynamic engine invented by
Thomas.C.B.Smith (Cambridge University).
Mr.Smith gave a performance and a demonstration on his engine on the
12th ISEC in Durham.
The engine is a phase change engine, so it's not a Stirling engine.
It works on a Rankine cycle,
using a liquid piston, but in difference to former liquid piston
engines it works on very low delta T
and it has no resonance acting in it, so no inertia is needed to
restart the cycle.
Mr.Smith uses a special liquid, which he keeps as a secret, but for
me it looks like ether,
methylalcohol or even alcohol may do it (or better the liquid of the
See the rough drawing BasicNIFTE.bmp in the folder NIFTE in our
Here a diaphragm is mounted between the working liquid and the
water, as in Smith's model
engine the two liquid were seperated only by their physical
behaviour (specific weight).
The engine works as following:
At start the liquid's level in the heater/cooler chamber (right) is
higher than in the drawing.
the heater heats up the liquid partly and vapourises it > pressure
rises and the liquid's level
(surface) gets pressed down (left)(and so water is pumped out from
the pump chamber).
The pressure also acts on the liquid's level(surface) in the
heater/cooler chamber, but
because of the narrow passage, only a little amount can flow back
(to the left).
If then the liquid's level falls below the heater fins, no more
liquid is boiled.
The walls of the tube and the cooler fins cool the gas and so the
Because it condenses, it sucks back the diaphragm (sucks in water)
and the level of
the liquid rises in the tube and rises slower(!) in the
heater/cooler chamber. The liquid will
rise up high in the left tube. The liquid's level will rise in the
heater/cooler chamber, too >>
>> until it has flooled to a significant height at the heater. Thenthe boiling of the gas
makes the pressure rise again...and it starts all over!
Mr.Smith showed, that adjusting the narrow passage, the frequency of
can be modified, although its speed is far below 60 strokes a minute
(more like 15 strokes
Mr.Smith claims an efficiency of 1.7%. I think this is very high for
such an engine, so we
have to test this, isn't it ?