Machine Design

Inventor's corner: Spiral-chambered turbine engine packs a one-two punch

Alexander Van Holstyn’s Reflective Pulse Engine, a spiral-chambered turbine, fires each chamber sequentially to maximize energy potential. Currently, the engine is under development. The naturally aspirated prototype will fire but does not yet run on its own, says Van Holstyn. It’s made out of mower-engine parts, automotive-ignition components, and a fabricated rotor.

The engine works like this: An outside compressed-air supply enters the intake side through a bypass port into the rotating chambers. Fuel is injected through the port and ignited in the chamber. Combustion follows the spiral path to the outer edge of the rotor and forms a flame wall and shock wave. The engine, therefore, produces two types of energy. The design separates both types and uses them to boost rotation in two separate ways.

The shock wave exits from the chamber and is reflected back to the rotor to generate additional rotation energy at lower rpms. The remaining hot gases route through the housing to recess vanes in the rotor and apply more pressure on the rotor before being expelled out the back side. All the work is done at the perimeter of the rotor, which yields maximum leverage and instant conversion to rotation.

The design accommodates many engine configurations with multiple chambers in a rotor. Their size and shape can also be varied. Thus, the engine is an entirely new design platform for engines rather than an improvement on current designs. The engine only has the compressor and electric alternator for load and almost zero friction.

According to Van Holstyn, the design uses the best features of the piston engine, a contained explosion, and many features of turbines, except for constant combustion. The mathematical model suggests that the engine produces more horsepower and torque than comparable piston engines when intake pressures exceeds 2 atm. The engine can also run at lower rpm ranges similar to a piston engine.

“I have always had a passion for the question, ‘What is the best engine design between the gas turbine and the piston engine?’,” says Van Holstyn. “I first thought of the basic concept of the Reflective Pulse Engine in the early 1970s in a high-school physics class, but also assumed if it was a good idea somebody would have done it already. I put the idea aside as my career took me other directions.

“I revisited the concept about 10 years ago and I rolled it around in my head many times before I started working on it. I researched the patent files and found no comparable design. I found patents on several types I had thought of before such as radial-vane engines and orbital lobes that use an internal-compression cycle, but have seal issues.

“The funny part is I could not make it through college mathematics, so I am not an engineer. I have since patented the basic design and have started working with a physicist to apply for grants.”

The Web site is and the patent is #7,963,096. Reach Van Holstyn at [email protected].

© 2012 Penton Media, Inc.

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