“A long time ago I became possessed of a desire to produce an engine as simple as my induction motor; and my efforts have been rewarded.  No mechanism could be simpler, and the beauty of it is that almost any amount of power can be obtained from it.  In the induction motor I produced the rotation by setting up a magnetic whirl, while in the turbine I set up a whirl of steam or gas.” - (Tesla 1906a)

Tesla, despite his inarguable genius, created many enemies in the course of his career.  In 1905, the year in which Tesla’s patents on the AC induction motor expired, despite his role in creating the multi-billion industry around such an invention, was nearly financially ruined, in part from relentless and vicious attacks from his opponents, describing him as a “poet and a visionary”, rather than one whose inventions could have any widespread, commercial use.  Thus, the impetus for what Tesla has called “the greatest of my inventions”, was born (Stockbridge 1911).  This invention was the bladeless turbine.

At this point in time, a turbine was a machine that consisted of blades that fluid or steam would ‘push’, causing a rotation which would generate power.  The general theory of fluid mechanics states that gases and stream would adhere to these blades and propel them at a high velocity.  However, the design Tesla had in mind would have nothing be deflected nor pushed by the fluid.  Rather, in Tesla’s device, there would be a “no slip” situation: the fluids in contact with the various surfaces would have a thin, outer layer having the same velocity as that of the surface.  The layer of fluid in contact with the surface would ideally bring the surface to the same velocity the fluid is moving at.

This is a picture of the original bladeless turbine that Tesla sent to the patentoffice, with a note that: "In the practical application of mechanical power based on the use of fluid as the vehicle of energy, it has been demonstrated that, in order to attain the highest economy, the changes in velocity and direction of movement of the fluid should be as gradual as possible."  He would attempt to achieve this by harnessing the "internal forces opposing molecular separation" and "the shock of the fluid against the asperities of the solid substance".  The pump discs shown would be keyed to a shaft (the dark, vertically aligned rod on the upper representation), while each disc would have a hole cut in the center, "preferably curved, as shown", Tesla noted.  To reduce clogging, Tesla recommended that a solid disk or a set of disks could be used.

The inlet for the fluids are shown in blue.  When the rotational force from the fluids strike the shaft, this would rotate the keyed disks, causing the fluid itself to rotate and move to the outer disks.  Depending upon the viscosity of the fluid, the fluid may complete an entire rotation before reaching the edge of the disks, depending on many factors, ranging from the viscosity of the fluid, the speed of rotation, and the width between the disks.

The exit path of the fluids are highlighted in red.  The disks would rotate counterclockwise as Tesla has represented in this rendition.  Tesla himself notes that: "... the spacing [of the disks] should be such that the entire mass of the fluid, before leaving the runner [the disks], is accelerated to a nearly uniform velocity, not much below the periphery of the disks under normal working conditions and almost equal to it when the outlet is closed and the particles move in concentric circles."

Tesla was awarded this patent on May 6th, 1913, as U.S. patent #1,061,142.  In actuality, Tesla applied for two patents in regards to this device: patent #1,061,142 "Fluid Propulsion", and patent #1,061,206, "Turbine".

There were a number of advantages to Tesla's radical new invention.  For one, bladed turbines are very high-precision machines built to specific tolerances.  As a result, the creation of such a device is both long and expensive.  As well, bladed turbines are not reversible, whereas, Tesla's device was.  Finally, Tesla himself claimed that while running on steam, his device could achieve up to a 95 percent efficiency.  Even today, bladed turbines operate at approximately 60 to 70 percent efficiency.  Tesla's design, however, had one fatal flaw to it.  In designs that used both higher speed and higher power, the disks would greatly warp and distort at extended periods of usage.  Even today, the alloy of disks are not powerful enough to withstand the tremendous temperatures (over 3000 Celsius) and pressures they are subjected to.  In the 1950s and 60s, Professor Warren Rice created his own version of Tesla's bladeless turbine, which operated with a 41 percent efficiency.  This approximated Tesla's own experiments, but fell far short of Tesla's claim of a 97 percent efficiency.

Tesla's invention was on constant attack from the Edison staff, which declared the turbines unsatisfactory and spread rumors of the device being a complete failure.  Westinghouse also refused to partake of this invention.  Allis Chalmers Manufacturing Company of Milwaukee, however, took up Tesla's design, but the problems with the device discussed above were readily apparent, as Hals Dahlstrand, consulting engineer for Allis Chalmers, reported: "the disks had distorted to a great extent and the opinion was that these disks would ultimately have failed if the unit had been operated for any length of time."  Tesla provided insufficient information to the engineers, and simply walked out, stating, "They would not build the turbines as I wished."  The turbines took twenty years of Tesla's life, and at the end, his reputation was further damaged and he was even more trouble financially than before.

Bibliography

Cheney, Margaret and Robert Uth.  "Tesla: Master of Lightning" Barnes & Noble Inc., 1999.

"Tesla Turbine Pump (from Internet Glossary of Pumps)", http://www.animatedsoftware.com/pumpglos/teslapum.htm

"Lindsay's Technical Archive: Tesla Turbine", http://www.lindsaybks.com/arch/turbine/