Download or read book The Effect of Pulse Length and Ejector Radius on Unsteady Ejector Performance written by Jack Wilson and published by BiblioGov. This book was released on 2013-08 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thrust augmentation of a set of ejectors driven by a shrouded Hartmann-Sprenger tube has been measured at four different frequencies. Each frequency corresponded to a different length to diameter ratio of the pulse of air leaving the driver shroud. Two of the frequencies had length to diameter ratios below the formation number, and two above. The formation number is the value of length to diameter ratio below which the pulse converts to a vortex ring only, and above which the pulse becomes a vortex ring plus a trailing jet. A three level, three parameter Box-Behnken statistical design of experiment scheme was performed at each frequency, measuring the thrust augmentation generated by the appropriate ejectors from the set. The three parameters were ejector length, radius, and inlet radius. The results showed that there is an optimum ejector radius and length at each frequency. Using a polynomial fit to the data, the results were interpolated to different ejector radii and pulse length to diameter ratios. This showed that a peak in thrust augmentation occurs when the pulse length to diameter ratio equals the formation number, and that the optimum ejector radius is 0.87 times the sum of the vortex ring radius and the core radius.

Download or read book Unsteady Ejector Performance An Experimental Investigation Using a Pulsejet Driver written by Daniel E. Paxson and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Propulsion and Power written by and published by . This book was released on 2008 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book UNSTEADY EJECTOR PERFORMANCE AN EXPERIMENTAL INVESTIGATION USING A PULSEJET DRIVER NATIONAL AERONAUTICS AND SPACE ADMINISTRATION JULY written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 41st AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 10 13 July 2005 Tucson Arizona 05 3800 05 3849 written by and published by . This book was released on 2005 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 41st AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 10 13 July 2005 Tucson Arizona 05 4200 05 4249 written by and published by . This book was released on 2005 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Technology 2002 written by and published by DIANE Publishing. This book was released on with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Properties of Primary Fluid on Performance of Cylindrical Shroud Ejectors written by Fred D. Kochendorfer and published by . This book was released on 1954 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steady Flow Ejector Research Program written by Lockheed-Georgia Company and published by . This book was released on 1961 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted to determine the jet thrust augmentation under static conditions for rectangular parallel-divergent wall ejector configurations with multiple primary nozzles. The effect of various geometrical and flow parameters were investigated in order to provide design information. Parameters investigated included the ratio of the ejector exit area to the primary nozzle area, the diffuser angle, the mixing section length, the primary nozzle position, the entrance radius, the number of primary nozzle rows, and the primary nozzle pressure ratio and temperature ratio. The test results are generalized to obtain curves relating the augmentation factor to ejector geometry and flow parameters over a wide range of ejector exit to primary nozzle area ratios. (Author).

Download or read book Unsteady Ejector Performance An Experimental Investigation Using a Resonance Tube Driver written by Jack Wilson and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Model of Pulsed Ejector Thrust Augmentation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-29 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple model of thrust augmentation from a pulsed source is described. In the model it is assumed that the flow into the ejector is quasi-steady, and can be calculated using potential flow techniques. The velocity of the flow is related to the speed of the starting vortex ring formed by the jet. The vortex ring properties are obtained from the slug model, knowing the jet diameter, speed and slug length. The model, when combined with experimental results, predicts an optimum ejector radius for thrust augmentation. Data on pulsed ejector performance for comparison with the model was obtained using a shrouded Hartmann-Sprenger tube as the pulsed jet source. A statistical experiment, in which ejector length, diameter, and nose radius were independent parameters, was performed at four different frequencies. These frequencies corresponded to four different slug length to diameter ratios, two below cut-off, and two above. Comparison of the model with the experimental data showed reasonable agreement. Maximum pulsed thrust augmentation is shown to occur for a pulsed source with slug length to diameter ratio equal to the cut-off value.Wilson, Jack and Deloof, Richard L. (Technical Monitor)Glenn Research CenterTHRUST AUGMENTATION; MATHEMATICAL MODELS; FLOW VELOCITY; HARTMANN-SPRENGER TUBES; VORTEX RINGS; PULSED JET ENGINES; EJECTORS...

Download or read book A Simple Model of Pulsed Ejector Thrust Augmentation written by and published by . This book was released on 2003 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 38th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 02 3900 02 3949 written by and published by . This book was released on 2002 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research and Technology 2002 written by and published by . This book was released on 2003 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of the Primary Flow Mach Number on Ejector Performance written by Paul Gustave Dougherty and published by . This book was released on 1966 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2005 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Experimental Investigation of Two Dimensional Thrust Augmenting Ejectors written by L. Bernal and published by . This book was released on 1984 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow-field within a two-dimensional thrust augmenting ejector has been documented experimentally. Results are presented on the mean velocity field and the turbulent correlations by laser doppler velocimeter, surface pressure distribution, surface temperature distribution, and thrust performance for two shroud geometries. The maximum primary nozzle pressure ratio tested was 3.0. The tests were conducted at primary nozzle temperature ratios of 1.0, 1.8, and 2.7. Two ejector characteristics lengths were identified based on the dynamics of the ejector flow field--a minimum length below which no significant mixing occurs, and a critical length associated with the development of U'V' correlation in the ejector. These characteristic lengths divide the ejector flow field into three distinctive regions: the entrance region where there is no direct interaction between the primary flow and the ejector shroud; the interaction region where there is an increased momentum of induced flow near the shroud surface; and a 'pipe' flow region characterized by an increased skin friction. The effect of the coflowing induced flow shown to produce inside the ejector a centerline velocity that increased over the free-jet data. The normalized turbulent correlations are found to be 25% lower than those in free jets. Effects of pressure ratio on the ejector flow field are small. Present measurements also show that the ejector performance was not influenced by the primary nozzle temperature ratio up to 2.7.