Statistics and scaling properties of temperature field in symmetrical non-Oberbeck-Boussinesq turbulent convection

TL;DR

This study experimentally examines how symmetrical non-Oberbeck-Boussinesq effects influence the statistical and scaling properties of temperature in turbulent convection, finding that most properties remain similar to the Oberbeck-Boussinesq case despite strong dependence on Rayleigh and Prandtl numbers.

Contribution

It provides the first detailed experimental analysis of SNOB effects on temperature field statistics and scaling in turbulent convection near the critical point of SF6.

Findings

Temperature fluctuation rms depends strongly on Ra and Pr.

Most statistical and scaling properties are unchanged from OB case.

SNOB effects do not alter the fundamental temperature field behavior.

Abstract

The influence of symmetrical non-Oberbeck-Boussinesq (SNOB) effect on statistical and scaling properties of temperature field in turbulent convection is investigated experimentally in $SF_{6}$ in the vicinity of its gas-liquid critical point (CP). The main conclusion of the studies is that besides the strong $Ra$ and $Pr$ dependence of the rms of temperature fluctuations normalized by the temperature difference across the cell, different from the Oberbeck-Boussinesq (OB) case of turbulent convection, all rest of statistical and scaling properties of temperature field discussed in details are the same as in the OB case.