New Directions in Turbine Design

January 23, 2002

Here we are at the beginning of the year 2002 in the snowmobiling capital of the country, experiencing record snowfalls -- in the wrong direction. Instead of having several feet of accumulated snow on the ground, we have several inches. 

People who deny that we are well into global warming trends are like the classic ostrich -- with their heads stuck in the sand (or somewhere else!)

The real purpose for experimenting with turbines is to arrive at a new engine design that will replace piston engines -- which account for up to half of the world's pollution problems. Those who believe the BS coming out of the White House about how a new welfare program for the auto industries will result in affordable fuel cell vehicles by 2008 ought to have their heads examined. After hundreds of millions of dollars thrown at them for the PNGV, we still don't have 80 MPG cars in our driveways. In spite of the rhetoric coming from politicians and industry "leaders", it's still up to us "little" guys to produce real technology.

Beyond the Box

This month we are going to look beyond the "Tesla Turbine Box" and examine a new direction for experimentation. We know that the boundary layer effect works in a typical Tesla type turbine with closely spaced disks. What we need to know is how well it performs compared to bladed-disk hybrid designs. In order to study such a comparison we need to build a couple of disk packs with identical spacing and modify only the elements between the disks. 

Referring to Figure A we see a typical Tesla configuration using his improved design with a star washer and round washer set. (Click on picture to view full size.)

Figure B shows our new direction in simple bladed systems. There are many factors you have to keep in mind when working with blades or, in this case, wing cross-sections. Disk spacing will have a big effect on winglet lift and drag properties. 

Some of the variables include:

• wing profile
• angle of attack relative to the inflowing gas
• the changing angle of incidence as the rotor and gas change their working relationship

Since we just completed working drawings and sent them to our laser cutter today, we won't have test results to post until next month.

What we really need is input from club members who have experience in turbine design & development, particularly in the field of high-pressure combustors with high efficiencies. If we are going to solve these man-made ills of industry we need to get more scientists, engineers and experimenters to work on projects other than money-making and stocks-gambling.

Until next time...

Ken Rieli

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