Combined Effect of Damping Screens and Stream Convergence on Turbulence
Abstract
An analysis is presented of the combined effect of a series of damping screens followed by an axisymmetric-stream convergence (or divergence) upon the mean-square fluctuation-velocity intensities, scales, correlations, and one-dimensional spectra of a turbulence field convected by a main stream. The treatment is restricted to negligible turbulence decay and linearized by postulating small fluctuation velocities and velocity gradients, and absence of viscosity except as simulated by the idealized screen action. Compressibility of the main stream is allowed for during passage through the contracting section. The density fluctuations associated with the turbulence field are regarded as negligible. Numerical results for the statistical quantities describing the turbulence field downstream of a screen-contraction configuration are obtained for the case of upstream isotropic turbulence. The action of the damping screens and the stream convergence is to distort this initially isotropic field into a field of turbulence symmetric about the longitudinal direction with the lateral fluctuation velocities greater in magnitude than the longitudinal velocities. An approximate method of taking into account the effects of turbulence decay upon the mean-square fluctuation velocities obtained for the case of negligible decay is presented. This method of correction together with the tabulation of fluctuation-velocity ratios over an extensive range of conditions should prove useful for engineering applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1953
- Accession Number
- ADA377188
Entities
People
- Maurice Tucker
Organizations
- National Aeronautics and Space Administration