Record Details
Turbulence structure within an inclined laboratory convection tank
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Turbulence structure within an inclined laboratory convection tank |
| Names |
Nance, Jon D.
(creator) Deardorff, James W. (advisor) |
| Date Issued | 1989-02-09 (iso8601) |
| Note | Graduation date: 1989 |
| Abstract | A baroclinic, convective mixed-layer was modeled, using water, in a laboratory convection tank identical to that used in the free convection study of Deardorff and Willis (1985). Baroclinicity and mean-flow shearing were achieved by tilting the tank by an angle of 1O⁰. The resulting mechanical-production rate of turbulence kinetic energy was comparable in magnitude to the buoyancy-production rate at mid-levels within the mixed-layer. Velocities were obtained by taking time-lapse photographs of neutrally-buoyant oil droplets suspended in the mixed-layer fluid. Variances and other statistical descriptors of the turbulence obtained from these velocities are presented in comparison to the free convection results of Deardorff and Willis (1985). The deviation of the present results from those of Deardorff and Willis (1985) are assumed to be related to the effects of mean-flow shearing and are explained wherever possible with the aid of an appropriate kinetic energy budget (kinetic energy, here, refers to the kinetic energy of the turbulence and is not to be confused with the kinetic energy of the mean-flow). The results indicate that a maximum in downstream horizontal kinetic energy at mid-levels within the mixed layer was generated by shear-production and, also, by conversion from vertical kinetic energy. In the lower mixed-layer, vertical kinetic energy was amplified by a mechanical-production term associated with the divergence of the mean vertical velocity. Total turbulence kinetic energy, normalized by the square of the convective velocity scale, was much larger at mid-levels than in Deardorff and Willis (1985) due to mechanical-production which is not accounted for by simple mixed-layer scaling. Horizontal turbulence structure was predominately controlled by convection while vertical turbulence structure was significantly altered by mean-flow shearing. |
| Genre | Thesis/Dissertation |
| Topic | Atmospheric turbulence |
| Identifier | http://hdl.handle.net/1957/28617 |
