Helical flow turbine

[Maylee]

Greetings all. I am new here and very happy to have discovered this great board.

I am wondering if anyone knows of any references regarding use of a helical flow machinery as a gas turbine. Helical flow compressors (also referred to as side channel blowers and regenerative compressors) are common. I am curious how well they would perform as a gas turbine. In this case they would operate much like a fluid coupling except the circumferential fluid motion is caused by expansion down a pressure gradient, rather than by an impeller. Any input is much appreciated.

 

[plasgears]

This reminds me of the ongoing debate about inversion of pumps and motors. Many pumps have been devised that cannot be inverted into efficient motors.

One curious inversion was designed by Von Ohain, Germany's pioneer jet engine designer. The compressor was centrifugal and the turbine was an inversion of a centrifugal compressor. The engine section looked like back to back centrifugal compressors with the combustor in between. It actually flew on the first German jet during WWII. All subsequent designs had either axial or centrifugal compressors driven by axial flow turbines.

Would your idea work? Perhaps, but you have decades of practical jet engine experience opposing you. That's the nature of sales resistance to progress. Whittle, the British designer of the jet engine, was pigeon-holed for a long time until friends, who knew better, rescued him from oblivion. It delayed the Allied jet engine for years.

 

[Warpspeed]

Maylee, do a google search of the "Tesla Turbine" it has many of the features you mention.

The only problem I can see with radial flow machinery as applied gas turbines is packaging. Small experimental gas turbines have been built using ordinary turbocharger components.

Nicola Tesla was a very clever fellow, and a lot of his proven ideas still await mass application.

 

[Maylee]

Thanks for the comments but I'm still left wondering about feasibility of a helical flow gas turbine. I've found a few patents claiming this works but no evidence its ever been used in the real world.

Allow me to restate the question...

As we know, the impeller of a torque converter imparts a circumferential velocity on a working fluid. Interaction of the working fluid with the turbine blades results in torque at the output shaft. This interaction also results in variations in circumferential velocity which in turn lead to radial flow. Superposition of the radial and circumferential velocities produce helical streamlines, hence the terminology - helical flow turbine.

So, the questions is... what if one where to eliminate the impeller and instead duct a pressurized gas so it expands in a circumferential direction. Circumferential flow is now driven by enthalpy change rather than the impeller but I content that a helical flow pattern will develop for the same reasons as in a torque converter. Anyone ever heard of such a gas turbine?

 

[plasgears]

Don't be discouraged; do the math/fluid flow/cycle analyses; plan some component tests if feasible. Good luck.