Timedependent convection under reduced gravity
Abstract
The transient development of thermal convection in a rectangulr container is theoretically and experimentally investigated for the case of a timedependent body force. The time law according to which convective streaming develops when an instantaneous acceleration in the form of a step function acts on a thermally layered fluid is examined. Explicit, twodimensional differential equations are used to calculate the timedependent convection, and the numerical results are compared with analytical solutions based on linear theory. The transient development of the flow field is quantitatively studied using differential interferometry. The characteristic development times for the thermal convection are presented as a function of the Rayleigh and Prandtl numbers and of the angle between the temperature gradient and the direction of acceleration. The results are used to evaluate the extent to which timedependent g disturbances in a space laboratory can induce noticeable convection flows.
 Publication:

NASA STI/Recon Technical Report A
 Pub Date:
 October 1982
 Bibcode:
 1982STIA...8312993K
 Keywords:

 Computational Fluid Dynamics;
 Convective Flow;
 Finite Difference Theory;
 Free Convection;
 Reduced Gravity;
 Time Dependence;
 Differential Equations;
 Prandtl Number;
 Rayleigh Number;
 Space Commercialization;
 Temperature Gradients;
 Two Dimensional Flow;
 Fluid Mechanics and Heat Transfer