Accession Number : ADA261542


Title :   Measurements of Scalar Power Spectra in High Schmidt Number Turbulent Jets


Descriptive Note : Technical rept. 1 Jun-1 Nov 1992


Corporate Author : CALIFORNIA INST OF TECH PASADENA GRADUATE AERONAUTICAL LABS


Personal Author(s) : Miller, Paul L ; Dimotakis, Paul E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a261542.pdf


Report Date : 09 Nov 1992


Pagination or Media Count : 25


Abstract : Single-point, jet-fluid concentration measurements obtained from high Schmidt number (Sc -- 1.9 x 10 to the 3rd power) turbulent jets permit an investigation of temporal scalar power spectra, for *et Reynolds numbers in the range of 1.25 less than or equal to Re x 10-4 less than or equal to 7.2. At intermediate scales, we find a spectrum with a logarithmic derivative (slope) that is increasing with Reynolds number, in absolute value, but less than 5/3 at the highest Reynolds number in our experiments. At the smallest scales, our spectra exhibit no 1-k power-law behavior, possessing a log-normal region over a range of scales exceeding a factor of 40, in some cases.


Descriptors :   *TURBULENT FLOW , *JET FLOW , *JET PROPULSION , SIGNAL PROCESSING , MEASUREMENT , POWER SPECTRA , SLOPE , MIXING , REYNOLDS NUMBER , JET MIXING FLOW , NOZZLE GAS FLOW , ARGON LASERS , VISCOSITY , NOZZLES , SPECTRA , OPTICAL DETECTION , TURBULENCE


Subject Categories : Fluid Mechanics
      Jet and Gas Turbine Engines


Distribution Statement : APPROVED FOR PUBLIC RELEASE