Test Time in Low Pressure Shock Tubes
Author: Aerospace Corporation
Publisher:
Published: 1962
Total Pages: 86
ISBN-13:
DOWNLOAD EBOOKRead and Download eBook Full
Author: Aerospace Corporation
Publisher:
Published: 1962
Total Pages: 86
ISBN-13:
DOWNLOAD EBOOKAuthor: Aerospace Corporation
Publisher:
Published: 1963
Total Pages: 72
ISBN-13:
DOWNLOAD EBOOKShock tube test time limitation due to the premature arrival of the contact surface is analytically investigated for wholly turbulent wall boundary layers. The results are compared with those for wholly laminar wall boundary layers. Working curves are presented for more accurate estimates of test time in specific cases. (Author) -- NTRL website.
Author:
Publisher:
Published: 2015
Total Pages: 15
ISBN-13:
DOWNLOAD EBOOKSeveral techniques have been developed for obtaining long, constant-pressure test times in reflected shock wave experiments in a shock tube, including the use of driver inserts, driver gas tailoring, helium gas diaphragm interfaces, driver extensions, and staged driver gas filling. Here, we detail these techniques, including discussion on the most recent strategy, staged driver gas filling. Experiments indicate that this staged filling strategy increases available test time by roughly 20 % relative to single-stage filling of tailored driver gas mixtures, while simultaneously reducing the helium required per shock by up to 85 %. This filling scheme involves firstly mixing a tailored helium-nitrogen mixture in the driver section as in conventional driver filling and, secondly, backfilling a low-speed-of-sound gas such as nitrogen or carbon dioxide from a port close to the end cap of the driver section. Using this staged driver gas filling, in addition to the other techniques listed above, post-reflected shock test times of up to 0.102 s (102 ms) at 524 K and 1.6 atm have been obtained. Spectroscopically based temperature measurements in non-reactive mixtures have confirmed that temperature and pressure conditions remain constant throughout the length of these long test duration trials. Finally, these strategies have been used to measure low-temperature n-heptane ignition delay times.
Author: Anatol Roshko
Publisher:
Published: 1960
Total Pages:
ISBN-13:
DOWNLOAD EBOOKAuthor: Virgil A. Sandborn
Publisher:
Published: 1962
Total Pages: 15
ISBN-13:
DOWNLOAD EBOOKAuthor: Jacklyn Higgs
Publisher:
Published: 2022
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKA new shock tube test section has been designed and manufactured for the purpose of increasing the test time and expanding the applications of the shock tube for a multitude of ongoing and future projects. One purpose for the test section extension is to allow for flow visualization of droplets impacted by a shock wave for the interaction of hypersonic vehicles and atmospheric disturbances. Another purpose is to measure behind the incident shock to capture the chemical kinetics for a high-altitude environment and low-pressure, high-temperature space applications. This new test section contains 24 round optical ports for laser spectroscopy for multiple measurement locations in addition to 3 rectangular ports upstream for introducing and imaging droplets in the tube. StanShock was used to simulate the expected test time for the desired temperatures and pressures. This was compared against theoretical calculations of test time as a function of distance and velocity of the shock. The optimal length of the extension of 5 feet was then determined based on minimum required test time and limitations of the physical lab space.
Author: S. P. Pfaff
Publisher:
Published: 1958
Total Pages: 30
ISBN-13:
DOWNLOAD EBOOKAuthor: Theodore A. Brabbs
Publisher:
Published: 1965
Total Pages: 20
ISBN-13:
DOWNLOAD EBOOKAuthor: H. Mirels
Publisher:
Published: 1966
Total Pages: 31
ISBN-13:
DOWNLOAD EBOOKShock tube flow nonuniformity is investigated in the limit where the shock and contact surface have reached their maximum separation. Ideal gases are considered. It is found that all fluid properties increase in value between the shock and contact surface. The nonuniformity is greatest when gamma (ratio of specific heats) is large and M sub s (shock Mach number) is low. For gamma = 5/3 and M sub s> or = 3, the static temperature, density, and pressure increase by about 8, 12 and 20%, respectively; the stagnation temperature increases by about 35%, and the stagnation pressure, dynamic pressure, and stagnation point heat transfer increase by about a factor of 2. These results apply to turbulent as well as laminar boundary layers. The variation of flow properties with distance behind the shock, as well as particle time of flight, is given for both wholly laminar and wholly turbulent wall boundary layers. These results are particularly important for chemical rate and heat transfer studies. (Author).
Author: Irving Israel Glass
Publisher: University of Toronto Press
Published: 1970-12-15
Total Pages: 852
ISBN-13: 1487597584
DOWNLOAD EBOOKThis volume contains the proceedings of a symposium held at the University of Toronto in June 1969. The symposium consisted of six sessions; each containing an invited paper, followed by six contributed papers reporting on recent, relevant research and development. The topics are: a review of research problems in basic shock tube flows and the possibilities for the shock tube in the future; driving techniques; explosive drivers; theoretical and experimental research in electromagnetic shock tubes; chemical kinetics and spectroscopy; and a review of shock tube diagnostics, instrumentation and fundamental data as well as the measurement of physical quantities.