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Experimental investigation of unsteady thrust augmentation using a speaker-driven jet
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Wernet, Mark P. Paxson, Daniel E. John, Wentworth T. |
| Copyright Year | 2007 |
| Description | An experimental investigation is described in which a simple speaker-driven jet was used as a pulsed thrust source (driver) for an ejector configuration. The objectives of the investigation were twofold. The first was to expand the experimental body of evidence showing that an unsteady thrust source, combined with a properly sized ejector generally yields higher thrust augmentation values than a similarly sized, steady driver of equivalent thrust. The second objective was to identify characteristics of the unsteady driver that may be useful for sizing ejectors, and for predicting the thrust augmentation levels that may be achieved. The speaker-driven jet provided a convenient source for the investigation because it is entirely unsteady (i.e., it has no mean velocity component) and because relevant parameters such as frequency, time-averaged thrust, and diameter are easily variable. The experimental setup will be described, as will the two main measurements techniques employed. These are thrust and digital particle imaging velocimetry of the driver. It will be shown that thrust augmentation values as high as 1.8 were obtained, that the diameter of the best ejector scaled with the dimensions of the emitted vortex, and that the so-called formation time serves as a useful dimensionless parameter by which to characterize the jet and predict performance. |
| File Size | 1971373 |
| Page Count | 8 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20070022506 |
| Archival Resource Key | ark:/13960/t58d4wb0j |
| Language | English |
| Publisher Date | 2007-03-01 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Thermodynamics Root-mean-square Errors Electric Potential Turbulence Jet Flow Enthalpy Reynolds Number Performance Prediction Pulsejet Engines Unsteady Flow Dimensionless Numbers Emittance Digital Techniques Ejectors Thrust Augmentation Particle Image Velocimetry Mathematical Models Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
