Experimental observations of double diffusive natural convection in solar ponds with nonlinear salinity profiles

Conference · Mon Apr 01 00:00:00 EST 1985

OSTI ID:5243547

Kirkpatrick, A T; Gordon, R F; Johnson, D H

A solar pond can be used as a thermal energy source provided that convective instabilities do not occur. This paper experimentally examines the stability of a fluid layer with nonlinear salinity profiles. A nonlinear salt profile was set up in a 0.7m x 0.7m x 1.4m deep tank, and the water was heated by a solar radiation simulator. Three experiments were conducted, each over a time scale of about one week. An instability was produced in two of the experiments. The instabilities occurred at the location of the weakest salinity gradient, and were confined to a narrow depth, as predicted by theory. A local length scale was used to produce a stability parameter, the ratio of thermal to solute Rayleigh numbers. It is shown that for nonlinear solute gradients, the appropriate length scale is based on the radius of curvature of the salinity distribution. With this choice of a length scale, good agreement was found between theory and experiment for the onset of an instability. However, only fair agreement was obtained for the disturbance frequency.

• Research Organization: Colorado State Univ., Fort Collins (USA). Dept. of Mechanical Engineering; Solar Energy Research Inst., Golden, CO (USA)
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 5243547
• Report Number(s): SERI/TP-252-2677; CONF-840402-8; ON: DE85000515
• Resource Relation: Conference: 6. annual ASME Solar Energy Division technical conference, Las Vegas, NV, USA, 10 Apr 1984; Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SOLAR PONDS
NATURAL CONVECTION
MATHEMATICAL MODELS
SALINITY GRADIENTS
SOLAR SIMULATORS
STABILITY
TEMPERATURE GRADIENTS
ANALOG SYSTEMS
CONVECTION
ENERGY TRANSFER
EQUIPMENT
FUNCTIONAL MODELS
HEAT TRANSFER
MASS TRANSFER
PONDS
SIMULATORS
SOLAR COLLECTORS
SOLAR EQUIPMENT
SURFACE WATERS
141000* - Solar Collectors & Concentrators