Digital particle image velocimetry/thermometry and application to the wake of a heated circular cylinder

• Published in: Experiments in fluids 2001-03, Vol.30 (3), p.327-338
• Main Authors: PARK, H. G, DABIRI, D, GHARIB, M
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Instrumentation for fluid dynamics; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Jets; Physics; Thermal instruments, apparatus and techniques; Thermometry; Turbulent flows, convection, and heat transfer; Wakes
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s003480000199

Digital particle image velocimetry/thermometry (DPIV/T) is a technique whereby the velocity and temperature fields are obtained using thermochromic liquid crystal (TLC) seeding particles in water. In this paper, the uncertainty levels associated with temperature and velocity measurements using DPIV/T are studied. The study shows that large uncertainties are encountered when the temperature is measured from individual TLC particles. Therefore, an averaging procedure is presented which can reduce the temperature uncertainties. The uncertainty is reduced by computing the average temperature of the particles within the common specified sampling window used for standard DPIV. Using this procedure, the velocity and temperature distributions of an unsteady wake behind a heated circular cylinder are measured experimentally at Re = 610. The instantaneous DPIV/T measurements are shown to be useful for computing statistical flow quantities, such as mean and velocity-temperature correlations. (Author)