タイトル | Two Point Space-Time Correlation of Density Fluctuations Measured in High Velocity Free Jets |
本文(外部サイト) | http://hdl.handle.net/2060/20060024560 |
著者(英) | Panda, Jayanta |
著者所属(英) | Ohio Aerospace Inst. |
発行日 | 2006-06-01 |
言語 | eng |
内容記述 | Two-point space-time correlations of air density fluctuations in unheated, fully-expanded free jets at Mach numbers M(sub j) = 0.95, 1.4, and 1.8 were measured using a Rayleigh scattering based diagnostic technique. The molecular scattered light from two small probe volumes of 1.03 mm length was measured for a completely non-intrusive means of determining the turbulent density fluctuations. The time series of density fluctuations were analyzed to estimate the integral length scale L in a moving frame of reference and the convective Mach number M(sub c) at different narrow Strouhal frequency (St) bands. It was observed that M(sub c) and the normalized moving frame length scale L*St/D, where D is the jet diameter, increased with Strouhal frequency before leveling off at the highest resolved frequency. Significant differences were observed between data obtained from the lip shear layer and the centerline of the jet. The wave number frequency transform of the correlation data demonstrated progressive increase in the radiative part of turbulence fluctuations with increasing jet Mach number. |
NASA分類 | Aircraft Propulsion and Power |
レポートNO | E-15470 NASA/CR-2006-214222 AIAA paper 2006-0006 |
権利 | No Copyright |
URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/218387 |