PIV Measurement of Flow Field around Film Boiling in He II

Film boiling phenomena in He II were studied using the PIV (Particle Image Velocimetry). Noisy and silent film boiling states were generated on/around a planar or a cylindrical heater. Tracer particles were neutrally buoyant solid H2-D2 particles. The motions of vapour bubble and of tracer particles were PIV-analyzed. The velocity field was found to be composed of AC and DC velocity components. The AC component is caused by the dynamic behaviour of vapour, and the DC results primarily from the thermal counter flow. The time-averaged PIV velocity field provides with the flow field characteristics of each boiling mode.