The PJ8 and PJ15 pulsejet engines have been designed and constructed in order to provide the following features:
These simple, effective, light-weight engines can be put to many different uses including:
Basically an enhanced Schmidt tube design, these engines have an enlarged combustion zone, straight tailpipe and divergent tailcone.
The valving system uses a mix of traditional petal-valves and two unique features perfected after almost two years of research and development.
On top of this, the design of the PJ8 and PJ15 valve systems includes a revolutionary 3-part "stacked" valve retainer that further protects the valves from heat-damage while actually improving the speed of valve actuation.
The overall engine design and the valving system have been optimized to extract the maximum available amount of power that can be obtained from the traditional pulsejet layout. (sample plans).
The use of stainless steel for "hotzone" components protects against corrosion and ensures the engine will withstand the very high operating temperatures found in pulsejets. Although these engines run red-hot and the stainless discolors to a gun-metal grey color due to the heat, they won't rust or flake and the changes are purely cosmetic.
Most of the rest of the engine is turned or spun from 6061 or other high-strength corrosion-resistant aluminum.
Thanks to this careful choice of materials and innovative construction techniques, the PJ15 weighs in at just 2.75lbs in direct injection form and 2.8lbs when normally aspirated.
See It Run
Note, the engine is not really glowing white hot in this video -- it's simply that the video camera is particularly sensitive to infrared so that any significant heat appears white.