Standard CFD RANS models are known to over-predict thermal stratification. Unfortunately a lack of well-defined high-resolution experimental data and measurements of the correlation between local velocity and density fluctuations (so-called turbulent fluxes) has hindered models advancement. A facility has been built in our group and equipped with advanced instrumentation to gather high-resolution data on the propagation of stratified fronts. In addition, we are developing novel experimental techniques to measure turbulent fluxes in buoyant flows. A proof-of-principle for simultaneous measurements of velocity and density fluctuations has been successfully completed combining PIV with wire-mesh sensors. The technique has won the Innovation Award at the CFD4NRS conference held at MIT in September 2016.