• Corpus ID: 230433695

Investigation of thrust augmentation and nozzle exit pressure in starting jets from a tube nozzle

@inproceedings{Moslemi2020InvestigationOT,
  title={Investigation of thrust augmentation and nozzle exit pressure in starting jets from a tube nozzle},
  author={Ali Akbar Moslemi},
  year={2020}
}
  • A. Moslemi
  • Published 25 December 2020
  • Engineering, Physics
It has been widely accepted that nozzle exit over-pressure is responsible for thrust augmentation in starting jets over steady jets and a few pulsed jet propulsion systems have been developed based on this finding. However, no other study has been conducted to confirm the nozzle exit over-pressure effect. In this paper, thrust and nozzle exit pressure are numerically investigated under different jet velocity programs (negative slope (NS), positive slope (PS) and impulsive). Starting jets are… 

References

SHOWING 1-10 OF 18 REFERENCES
Modelling circulation, impulse and kinetic energy of starting jets with non-zero radial velocity
Abstract The evolution of starting jet circulation, impulse and kinetic energy are derived in terms of kinematics at the entrance boundary of a semi-infinite axisymmetric domain. This analysis is not
Thrust augmentation and vortex ring evolution in a fully pulsed jet
The time-averaged thrust of an incompressible fully pulsed jet containing a period of no flow between pulses is studied experimentally as a function of pulsing duty cycle Sr_L and the ratio of the
The significance of vortex ring formation to the impulse and thrust of a starting jet
The recent work of Gharib, Rambod, and Shariff [J. Fluid Mech. 360, 121 (1998)] studied vortex rings formed by starting jets generated using a piston-cylinder mechanism. Their results showed that
An over-pressure correction to the slug model for vortex ring circulation
The slug model provides a formula for the circulation of vortex rings formed by starting jets ejected from a nozzle or orifice in terms of the time history of the jet velocity. For rapidly initiated
An experimental study of an axisymmetric turbulent pulsed air jet
An experimental study is carried out to elucidate the structure of a high Reynolds number (~105) turbulent pulsed jet. Particle image velocimetry measurements showed that the near flow field is
Effects of multijet coupling on propulsive performance in underwater pulsed jets
Despite the importance of pulsed jets for underwater propulsion, the effect of multiple-jet interactions remains poorly understood. We experimentally investigate how interactions between neighboring
Vortex-enhanced propulsion
It has been previously suggested that the generation of coherent vortical structures in the near-wake of a self-propelled vehicle can improve its propulsive efficiency by manipulating the local
Circulation Generation and Vortex Ring Formation by Conic Nozzles
Vortex rings are one of the fundamental flow structures in nature. In this paper, the generation of circulation and vortex rings by a vortex generator with a static converging conic nozzle exit is
Entrainment and thrust augmentation in pulsatile ejector flows
This study comprised direct thrust measurements, flow visualization by use of a spark shadowgraph technique, and mean and fluctuating velocity measurements with a pitot tube and linearized constant
The effect of Reynolds number on the propulsive efficiency of a biomorphic pulsed-jet underwater vehicle.
TLDR
The improved η(P)/η (P, ss) at lower Re suggests that pulsed-jet propulsion can be used as an efficient propulsion system for millimeter-scale propulsion applications.
...
1
2
...