Turbulent buoyant confined jet with variable source temperature

TL;DR

This study combines experimental and numerical methods to analyze how variable inlet temperatures affect the behavior and thermal stratification of confined buoyant turbulent jets, revealing nonlinear temperature variations and stratification effects.

Contribution

It introduces a comprehensive investigation of variable inlet temperature effects on buoyant jets using both experiments and simulations, highlighting nonlinear temperature profiles and stratification.

Findings

Temperatures vary nonlinearly along the jet axis.

Thermal stratification persists near the entrance region.

Inlet temperature variations influence buoyancy force and Richardson number.

Abstract

In this work, experimental and numerical investigations are considered for confined buoyant turbulent jet with varying inlet temperatures. Results of the experimental work and numerical simulations for the problem under consideration are presented. Four cases of different variable inlet temperatures and different flow rates are considered. The realizable k-epsilon turbulence model is used to model the turbulent flow. Comparisons show good agreements between simulated and measured results. The results indicate that temperatures along the vertical axis vary, generally, in nonlinear fashion as opposed to the approximately linear variation that was observed for the constant inlet temperature that was done in a previous work. Furthermore, thermal stratification exits particularly closer to the entrance region. Further away from the entrance region the variation in temperatures becomes relatively smaller. The stratification is observed since the start of the experiment and continues during whole time. Numerical experiments for constant, monotone increasing and monotone decreasing of inlet temperature are done to show its effect on the buoyancy force in terms of Richardson number