An instrumented tracer for Lagrangian measurements in Rayleigh-Bénard convection

Abstract

We have developed novel instrumentation for making Lagrangian measurements of temperature in diverse fluid flows. A small neutrally buoyant capsule is equipped with on-board electronics which measure temperature and transmit the data via a wireless radio frequency link to a desktop computer. The device has 80 dB dynamic range, resolving milli-Kelvin changes in temperature with up to 100 ms sampling time. The capabilities of these "smart particles" are demonstrated in turbulent thermal convection in water. We measure temperature variations as the particle is advected by the convective motion, and analyse its statistics. Additional use of cameras allow us to track the particle position and to report here the first direct measurement of Lagrangian heat flux transfer in Rayleigh-B{é}nard convection. The device shows promise for opening new research in a broad variety of fluid systems.

14 pages

References in corpus (2)

• Particles and fields in fluid turbulence
• Measurement of Lagrangian velocity in fully developed turbulence

Cited by in corpus (6)

• Ultimate Turbulent Taylor-Couette Flow
• Lagrangian temperature, velocity and local heat flux measurement in Rayleigh-Benard convection
• Smart Inertial Particles
• Simultaneous temperature and velocity Lagrangian measurements in turbulent thermal convection
• Characterizing flows with an instrumented particle measuring Lagrangian accelerations
• Design, construction and validation of an instrumented particle for the lagrangian characterization of flows. Application to gravity wave turbulence