Institute of Thermophysics

Liquid spraying and break-up of droplets in a transonic air flow

Sprays of water, ethanol, and acetone of micrometre-scale droplets are investigated in a transonic flow in a flat converging–diverging nozzle with a shock wave structure downstream. High-magnification two-frame shadowgraphy with a short interframe delay is used to investigate the...

Bubble dynamics during boiling on biphilic surfaces with cavity arrays

The boiling process on a biphilic copper surface with arrays of hydrophobic cavities approximately 100 µm in size and 780 µm in pitch was caught on video. The bubble departure diameters and frequencies were determined as functions of heat flux, and their rise velocities were dete...

Refining the liquidus temperature of the NaCl–KCl system

The liquidus temperature in the NaCl–KCl system was investigated using oscillation phase analysis (OPA). The study encompassed 14 samples with potassium chloride concentrations ranging from 0 to 100 mol %. As a result, the melting points of the pure components were established, a...

Influence of mechanical vibration on nucleate boiling heat transfer at different pressures

The paper presents results of experimental study on the influence of mechanical vibration on heat transfer and evaporation dynamics in nucleation boiling of saturated water (for the pressure interval 10 – 101.3 kPa). Relevance of the study is due to a demand in increasing the hea...

Control of semiconductor surface morphology and wettability via nanosecond laser texturing

Efficient thermal management in modern compact electronics requires surfaces with controlled wettability and strong wicking capability. Although laser-textured silicon is widely studied for its optical response, its wetting and capillary transport properties remain less explored....

Effect of passive perturbation from an obstacle on heat transfer in a turbulent bubble flow: experiment and numerical simulation

The influence of a passive perturbation from a vortex-generating rib on heat transfer in a bubble flow in a flat channel was studied experimentally and numerically. Wall temperature measurements were taken using an IR camera. Unsteady Reynolds-averaged Navier–Stokes equations, wr...

Liquid film thickness in a flat minichannel in turbulent gas-liquid film flow

This work deals with an experimental study of the thickness of a water film driven by a turbulent gas flow in a flat minichannel. It has been found that the transition from macro- to minichannels can lead to a significant reduction in film thickness under comparable parameters. A...