Accession Number : AD0014187


Title :   ONE-DIMENSIONAL FLUID FLOW PRODUCED BY CONFINED SPARKS


Corporate Author : OKLAHOMA UNIV RESEARCH INST NORMAN


Personal Author(s) : Atkinson, William R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/014187.pdf


Report Date : 30 Sep 1953


Pagination or Media Count : 69


Abstract : A shock tube was constructed in which the pressure difference is created by heating the compression-chamber gas with a spark from a capacitor capable of delivering 0.2 joules/cu cm to the gas in less than 20 microsec. A rotating-mirror camera was used to study the subsequent motion of He, Ne, A, and Xe luminosity. The observed fronts were classified into 2 groups: C-type luminous fronts which reflect before they reach a piston placed in the expansion chamber, and S-type luminous fronts which reach the piston before reflecting. For certain initial pressures and capacitor potentials, micrograms showed only a C-type front; this was interpreted as the contact surface. For other conditions a fainter S-type front preceded the C-type front; the S-type front was interpreted as a luminous shock front. The S-type front became more conspicuous with the reduction of the initial pressure until, at less than 1 mm Hg, C-type fronts sometimes became undetectable. This effect was attributed to ionization by the shock wave. The luminosity about 1 cm behind the contact surface was observed to decrease almost discontinuously to a very low value in the upper range of initial pressures. A shock of rarefaction was thought to be responsible for this phenomenon. Tabulated values of time and position relationships are included for all the gases used at various pressures and spark potentials. (See also AD14186)


Descriptors :   *SHOCK WAVES , TIME , IONIZATION , TABLES(DATA) , RAREFACTION , EXPANSION , CHAMBERS , CAPACITORS , SHOCK TUBES , LUMINOSITY , SPARKS


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE