Revisiting Mean Flow and Mixing Properties of Negatively Round Buoyant Jets Using the Escaping Mass Approach (EMA)

Aristeidis A Bloutsos,Panayotis C Yannopoulos

doi:10.3390/fluids5030131

Abstract

The flow formed by the discharge of inclined turbulent negatively round buoyant jets is common in environmental flow phenomena, especially in the case of brine disposal. The prediction of the mean flow and mixing properties of such flows is based on integral models, experimental results and, recently, on numerical modeling. This paper presents the results of mean flow and mixing characteristics using the escaping mass approach (EMA), a Gaussian model that simulates the escaping masses from the main buoyant jet flow. The EMA model was applied for dense discharge at a quiescent ambient of uniform density for initial discharge inclinations from 15° to 75°, with respect to the horizontal plane. The variations of the dimensionless terminal centerline and the external edge’s height, the horizontal location of the centerline terminal height, the horizontal location of centerline and the external edge’s return point as a function of initial inclination angle are estimated via the EMA model, and compared to available experimental data and other integral or numerical models. Additionally, the same procedure was followed for axial dilutions at the centerline terminal height and return point. The performance of EMA is acceptable for research purposes, and the simplicity and speed of calculations makes it competitive for design and environmental assessment studies.

Highlights

The effluents of a wastewater treatment plant or power plant cooling waters are usually discharged in large water bodies like ocean, lakes, etc
The escaping mass approach (EMA) model [74] is an integral model that describes the flow and mixing fields of inclined round or plane buoyant jets issuing into stationary ambient environment of mixing fields of inclined round or plane buoyant jets issuing into stationary ambient environment of uniform density
For the case of round buoyant jets, the conservation partial differential equations (PDE) of continuity, momentum and tracer have been formulated in a curvilinear cylindrical coordinate (PDE) of continuity, momentum and tracer have been formulated in a curvilinear cylindrical system, which is relative to the corresponding curvilinear orthogonal Cartesian coordinate system for coordinate system, which is relative to the corresponding curvilinear orthogonal Cartesian plane buoyant jets [84]

Summary

Introduction

The effluents of a wastewater treatment plant or power plant cooling waters are usually discharged in large water bodies like ocean, lakes, etc. The flow has positive buoyancy, forming turbulent buoyant plumes that affect the receiver. These flows have been extensively investigated through the years [1,2,3,4,5,6,7,8,9]. The emission of dense gases like chlorine, hydrogen fluoride or liquefied natural gas (LNG) occurs when they accidentally leak to the air environment (bounded or unbounded) [10,11]. These gases are usually toxic and/or flammable, causing serious adverse effects to human health, nonhuman biota and generally disasters. The accurate and fast prediction of the flow via mathematical models is crucial in evacuating affected areas and rescuing victims [12,13] and extremely important for the risk assessment of industries and storage areas that handle such hazardous materials [14,15,16]

Methods

Results

Conclusion