SINGLE FLOW AND MULTIPLE FLOW ENGINES pulsed jet engines can be classified according to the number
of flows which participate in the generation of thrust. This classification must be based on thermodynamic
considerations. In a steady flow engine all theoretical fluid particles follow all same path, this assumption
is not valid with the pulse jet engine. Impulse change in all particles of the working medium undergo
the same thermal cycle. Multiflow engines act in a manner that the working medium undergoes different
cycles.
In contrast to several previous designs, the tailpipe flare design and a shrouded tail design an important
design that will now be discussed in this section is a design where the tailpipe is constricted. A constriction
at the exit of the tailpipe in the form of a cone will reflect a shock wave and increase the upstream
propagating hammer wave.
