Date of Award


Document Type


Degree Name

Master of Science (MS)


Mechanical Engineering


The investigation was suggested by an earlier investigation done on a single valveless pulse jet engine at the University of North Dakota by Roger W. Engebretson. It was thought that if two of these engines could be coupled in such a manner that they would fire alternatively, the performance per engine could be improved. A literature search indicated that, while valved pulse jets had been successfully operated in the described manner, no one had previously operated two valveless pulse jet engines in phase opposition.

The objective of this project was to design a device for coupling two of these engines as prescribed above and to investigate the performance characteristics of the coupled engines.

As a result of this project, two valveless pulse jet engines have been successfully operated in a coupled manner and through the use of high speed photography, it was established that the engines were firing alternatively. The total thrust per engine and the total-thrust specific fuel consumption for the coupled engines were inferior to the respective values for Engebretson’s single engine. However, indications are that coupled engines have a potential for improvement through further research. In the thesis, six suggestions for further research projects are advanced.