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Author Matter, Zeitschrift ♦ Liicke, M.
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Energy Injection ♦ Random Stirring Force ♦ Stochastic Volume Force ♦ Simple Realization ♦ Stationary Energy Injection Rate ♦ Various Force Density Profile ♦ Spectral Distribution ♦ Energy Balance ♦ Model Volume ♦ Force Correlation ♦ General Relation ♦ Variable Size ♦ Navier-stokes Equation ♦ Stochastic Stirring Force ♦ Gaussian Distributed Force ♦ Hard Sphere ♦ Incom-pressible Fluid ♦ Energy Injection Rate ♦ Volume Force Model ♦ Combined System ♦ Velocity Field ♦ Fluid Volume Element ♦ Stochastic Volume ♦ Wavenumber Spectrum ♦ White Noise Frequency Spectrum ♦ Energy Injection Rate K-1
Abstract The wavenumber spectrum of the stationary energy injection rate into an incom-pressible fluid described by the Navier-Stokes equations is evaluated for some simple realizations of stochastic volume as well as stirring forces. A general relation between energy injection, fluid's response, and force correlations i derived which was previously shown to be particularly simple for Gaussian distributed forces with white noise frequency spectrum. For two kinds of such model volume forces the energy injection rates are calculated: Fluid volume elements of variable size around randomly chosen positions are forced in one model centralsymmetrically in the other one anti-symmetrically under inversion with various force density profiles. The circumstances under which both models display an energy injection rate ~ k-1 into a band d k around the wavenumber k are discussed. As a simple realization of stochastic stirring forces externally moved hard spheres immersed in the fluid are considered. The equation of motion and energy balance for the velocity field of the combined system is discussed. The spectral distribution of energy injection by stirring is shown to be that of a volume force model. I.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Publisher Date 1980-01-01