CaltechAUTHORS
  A Caltech Library Service

Impulse Generated by a Shock Tube in a Vacuum

Takashima, Yasuhiro and Kasahara, Jiro and Shepherd, Joseph E. and Funaki, Ikkoh (2008) Impulse Generated by a Shock Tube in a Vacuum. In: 46th AIAA Aerospace Sciences Meeting and Exhibit. American Institute of Aeronautics and Astronautics , Reston, VA, Art. No. 2008-987. ISBN 978-1-62410-128-1. https://resolver.caltech.edu/CaltechAUTHORS:20200124-145500606

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20200124-145500606

Abstract

Detonation tube specific impulse increases with decreasing ambient pressure for fully-filled conditions in a sub-atmospheric environment. In the present study, we use an open-end shock tube to simulate a detonation tube and investigate the dependence of the specific impulse on the propellant fraction, i.e., partial filing, in vacuum operation. The impulse is experimentally determined by hanging the shock tube in a ballistic pendulum arrangement inside a vacuum chamber. The shock tube driver section has a fixed length of 0.1 m and is filled to 1 MPa with various gases including helium, hydrogen, nitrogen, argon, and sulfur hexafluoride. The pressure inside the vacuum chamber is 5 Pa. The shock tube had constant area and different lengths (0-1.2 m) of the open-end driven sections (extension tubes) are used to vary the fraction or gas filling the shock tube (fill fraction) between 7.8% and 100%. The specific impulse is a weak function of extension tube length but varies strongly with the gas type. Dimensional analysis is used to correlate the data and we show that similar to data from detonation tubes, it is possible to correlate specific impulse with a single parameter that takes into account the lime scale for depressurization. The specific impulse is predicted using the method or characteristics ignoring two-dimensional and rarified gas effects at the tube exit. In agreement with the experiments, the specific impulse is predicted to increase slightly with extension tube length and vary inversely with the square root of the molecular weight of the gas. The specific impulse observed for SF₆ is about 25% higher that observed for the other gases with the same extension tube lengths, indicating an effect or vibration-translational energy exchange on the exhaust velocity.


Item Type:Book Section
Related URLs:
URLURL TypeDescription
https://doi.org/10.2514/6.2008-987DOIArticle
ORCID:
AuthorORCID
Shepherd, Joseph E.0000-0003-3181-9310
Additional Information:© 2008 by the American Institute of Aeronautics and Astronautics, Inc. Published online: 19 June 2012.
Group:GALCIT
Other Numbering System:
Other Numbering System NameOther Numbering System ID
AIAA Paper2008-987
Record Number:CaltechAUTHORS:20200124-145500606
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20200124-145500606
Official Citation:Impulse Generated by a Shock Tube in a Vacuum. Yasuhiro Takashima, Jiro Kasahara, Joseph Shepherd, and Ikko Funaki. 46th AIAA Aerospace Sciences Meeting and Exhibit. January 2008; doi: 10.2514/6.2008-987
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100910
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:25 Jan 2020 03:38
Last Modified:25 Jan 2020 03:38

Repository Staff Only: item control page