PIV Measurements and POD Analysis during Natural Convection with Protruded Heater in a Rectangular Enclosure

Abstract

An extensive measurement using 2-D Particle Image Velocimetry (PIV) technique has been carried out during natural convection with a heating sources protruded on the non-heated lower surface of a rectangular enclosure. A time-resolved data series have been captured to analyse the effect of different Rayleigh number on flow fields for fluid of Prandtl number 0.71. A fast and efficient data analysis tool based on the Proper Orthogonal Decomposition (POD) technique has been used to create low dimensional approximations of high dimensional systems for predicting the dominant flow structures. This includes interpolating results at off-design parameters, along with knowledge about contours of different higher modes as well as obtaining information about the energy content in each specific mode. The mean non fluctuating mode showed maximum energy and the same decreased with increasing mode number. This allowed a clear detailed understanding about the complex non-linearities in the problem using a linear decomposition technique