The objective of this research is the continued development and use of a high resolution particle image velocimeter to measure instantaneous velocity fields in water when the latter is heated from below. In addition, temperature will be measured and combined with momentum to investigate selected large-scale structures as a function of the Rayleigh number. These results, together with a suitable sequence of photographs depicting the evolution of the velocity field, will be used to investigate the relationship between large and small scales of motion, especially with respect to formulating improved relationships for sub-grid scale stresses in (large eddy) numerical simulations of turbulence.//
