Numerical simulation and analysis of confined turbulent buoyant jet with variable source

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 −ε turbulence model is used to model the turbulent flow. Comparisons show good agreements between simulated and measured results. The average deviation of the simulated temperature by realizable k −ε turbulent model and the measured temperature is within 2%. 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.

Simulation Study on Natural Ventilation Performance in a Low-Carbon Large-Space Public Building in Hot-Summer and Cold-Winter Region of China

“…Mayank et al [30] verified the accuracy of the model by using the realizable k-ε model to perform two-dimensional numerical simulations of a specially designed turbulent channel. Ami et al [31] used the realizable k-ε model to simulate constrained buoyant turbulent jets, where the accuracy of the model was verified by comparing the results of experiments and simulations. Stavrakaki et al [32] used the realizable k-ε model in an experimental study which validated the model.…”

Inward and Outward Opening Properties of One-Sided Windcatchers: Experimental and Analytical Evaluation

“…Equations ( 1) and ( 2) represent the Reynolds-averaged Navier-Stokes equations (RANS); Equation (3) represents the energy equation; and Equations ( 4) and ( 5) represent the turbulence equations. The mathematical model is described using the RANS and energy and the realizable k-turbulent equations [41][42][43][44][45]. The governing partial differential equations with their algebraic constraints are listed below.…”

Numerical Study of Multiple Momentum Jets in a Vegetated Crossflow

“…However, few studies related to multiple jets under the action of vegetation are available. Numerical simulations can provide more complete data and a better visualization of turbulent flows, which are difficult to measure accurately in experimental studies [25][26][27][28][29][30]. This study employs the numerical simulation method and determines the effects of jet spacing and jet-to-crossflow velocity ratio on the flow and turbulence characteristics of multiple jets in the vegetated channel.…”