was probably Tesla's last "sane" project before he wandered off
forever down the paths of crankdom. It's a high-speed bladeless
turbine that consisted of a series of smooth disks which were turned
by what is known today as a boundary-layer effect that relied on the
viscosity of a flowing gas or liquid rather than striking blades.
It was a neat little idea and showed a great deal of promise, but
Tesla treated it much like he did his teleautomation; it wasn't just a
clever invention, it was a revolution.
Tesla touted his turbine as a powerhouse in a hat.
He talked gleefully as replacing all other motors and engines as the
prime mover of civilisaton. He claimed that it was 97%
efficient, that it could run off of any fuel, and was streets ahead of
anything previous. In fact, tests showed that its efficiency was
only 41%; impressive, but not a quantum leap. Also, the high
speeds that the turbine needed to turn at were too great for the disks,
which distorted quickly at running speed; it didn't scale very easily;
and it performed poorly under load. Even today, when Tesla's
turbine is used in commercial pumps, the problem of materials for the
power-generating version has never been overcome. But that
didn't keep Tesla from declaring that one day his turbine would find
its way into power stations, ships, aeroplanes, airships, automobiles,
and death rays. Indeed, he even played about with sketching his
turbine motor car, which he claimed would be so efficient that it
could drive clear across the United States on a single tank of petrol.
Despite approaching Henry Ford with his wondrous invention, the Tesla
turbine motor car never got off the sketch pad, but his turbine did
end up in cars later on; as a speedometer.